Title Page
 Table of Contents
 Biographical sketch

Title: Second larval instars of Florida Anisoptera (Odonata)
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00099244/00001
 Material Information
Title: Second larval instars of Florida Anisoptera (Odonata)
Alternate Title: Anisoptera
Physical Description: vi, 125 leaves : ill. ; 28 cm.
Language: English
Creator: Dunkle, Sidney Warren, 1940-
Copyright Date: 1980
Subject: Dragonflies -- Florida   ( lcsh )
Odonata -- Florida   ( lcsh )
Insects -- Florida   ( lcsh )
Entomology and Nematology thesis Ph. D
Dissertations, Academic -- Entomology and Nematology -- UF
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
Thesis: Thesis--University of Florida.
Bibliography: Bibliography: leaves 117-123.
General Note: Typescript.
General Note: Vita.
Statement of Responsibility: by Sidney Warren Dunkle.
 Record Information
Bibliographic ID: UF00099244
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000014427
oclc - 06800100
notis - AAB7651


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Table of Contents
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    Table of Contents
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    Biographical sketch
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Full Text








I give my warmest thanks to Dr. Minter J. Westfall, Jr., who

inspired my early enthusiasm for dragonfly study, and who has main-

tained it at its present high level. He has generously contributed

advice, help, and facilities at every phase of this study.

I also sincerely thank the other members of my graduate com-

mittee, Dr. Stratton Kerr and Dr. F. Clifford Johnson, for their

advice and guidance. A special note of appreciation is due to

Dr. John W. Hardy, who provided friendly, personal encouragement

and helped me to obtain financial support.

Many people have helped obtain the specimens on which this

study is based, especially Sandra L. Skar, to whom I am most grateful.

Kenneth Knopf, Curtis Williams, and Michael May also contributed

critical specimens.



ACKNOWLEDGEMENTS . . . . . . . . . . . ii

ABSTRACT . . . . . . . . . . . . .

INTRODUCTION . . . ..... . . . . . 1

Scope of Species Coverage . . . . . . . 2
Scope of Morphological Knowledge of
Anisopteran Second Instars .. . . . ... 7

METHODS . . . . .. . . . . . . . . 16

Obtaining Fertile Anisoptera Eggs .. . . . . 16
Hatching Anisoptera Eggs . . . . . . .. 19
Preserving and Preparing Specimens . . . .. 19

RESULTS . . . . . .... . . . . . . . 23

Morphology of Anisopteran Second Instars . . .. 23
Antennae . . . . . . . . . . 24
Labium . . . . . . . . . . 27
Eyes . . . . . . . . . . 29
Epicranial Tubercles or Horns . . . .. 30
Thorax . . . . . . . . . . 30
Abdomen . . . . . . . . . . 31
Size . . . . . . . . . . . 31
Keys to Florida Anisopteran Second Instars. ... . 32
Key to Families . . . . . . . .. 33
Key to Aeshnidae . . . . . . . .. 35
Key to Gomphidae . . . . . . . .. 37
Key to Gomphus (Stylurus) . . . . ... 39
Key to Gomphus (Gomphus). . . . .... 40
Key to Corduliidae and Libellulidae . . . 42
Diagnostic Descriptions . . . . . . . 55
Petaluridae . . . . . . . . . 55
Aeshnidae .. .... . . . . 57
Gomphidae . . . . . . . . .. 64
Cordulegastridae . . . . . . . .. 73


Macromiidae . . . . . . . . 74
Corduliidae . . . . . . . . ... 76
Libellulidae . . . . . . . ... 84
Behavior . . . . . . . . . . . 103
Locomotion . . . . . . . ... 103
Taxes. . . . . . . . . . . 104

DISCUSSION . . . . . . . . . . . . 107

Taxonomic Problems . . . . . . . . .. 107
Arigomphus . . . . . . . ... 107
Gomphus (Stylurus) townesi . . . . .. .108
Libellula, Ladona, and Plathemis . . ... 108
Basiaeschna . . . . . . . ... 109
Non-Florida Species . . . . . . . ... 110
Epicranial Tubercles or Horns . . . . . ... 112

CONCLUSION . . . . . . . ... . . .115

LITERATURE CITED . . . . . . . . ... . .117

BIOGRAPHICAL SKETCH . . . . . . . . ... .. .124

Abstract of Dissertation Presented to the Graduate Council
of the University of Florida
in Partial Fulfillment of the Requirements
for the Degree of Doctor of Philosophy



Sidney Warren Dunkle

August, 1980

Chairman: Minter J. Westfall, Jr.
Major Department: Entomology and Nematology

Descriptions and identification keys are provided for Florida

anisopteran second instars, including all of the families, 78% of the

genera, and 62% of the 109 species breeding within the state. Com-

parative and supplementary data on 28 non-Florida species are also

given. A list of all previously published illustrations of anisopteran

first and second instars of the world is included. Methods of ob-

taining and hatching Anisoptera eggs are discussed, along with methods

of preparing specimens of second larval instars for examination.

The only known mid-ventral thoracic and abdominal spines in larval

Anisoptera were found in Arigomphus, evidence that this group should

be considered a genus instead of a suhgenus. Epicranial tubercles,

or horns, were found in 25 to 100% of the genera studied in Aeshnidae,

Gomphidae, Macromiidae, Corduliidae, and Libellulidae. Horns have

evolved independently many times in the Anisoptera and are probably

primarily sensory. The behavior of anisopteran second instars and the

use of characters of second instars in solving taxonomic problems

are discussed. Partial life histories for species of Cordulegastridae

and Macromiidae are the first to be described for these families.


The suborder Anisoptera of the insect order Odonata contains

approximately 287 species breeding in the continental United States

and Canada. The immature stages of these insects live in fresh water

or rarely on wet soil or in salt water. Anisoptera or dragonfly

immatures have recently shown increasing potential as indicator

organisms in assessing environmental water quality. Existing keys

for the identification of Nearctic species of immature Anisoptera,

such as Needham and Westfall (1955), work only for well grown specimens.

The present study was undertaken primarily to develop a key to the

youngest mobile immature stage of Florida Anisoptera. I hope that by

using both the keys presented here and keys to older immatures that

most of the specimens in any sample of immature Florida Anisoptera

can be identified. Another objective of this study was to provide

data bearing on taxonomic problems. The newly hatched immatures

show some different characters from fully grown individuals, and these

characters have not been used previously to assess phylogenetic


Before proceeding further, the usage of certain terms in the

following text must be explained. Immature Anisoptera are variously

known as nymphs, naiads, or larvae. I use larva to emphasize the

differences from the adults rather than the similarities to the

adults implied by nymph or naiad. The larva which hatches from the


egg resembles the embryo and has been regarded by many authors as a

separate stage, the pronymph or prolarva. However, it molts its

cuticle in the same way as later larval stags and is best considered

as the first larval instar. An instar is the insect body between

successive molts. The first larval instar cannot walk or eat, and the

stadium lasts only a few seconds to about 2 hours in different species.

The second larval instar, which exists between the first and second

molts, is the earliest mobile feeding stage. Thus my usage of second

larval instar corresponds with that of many recent authors such as

Corhet (1963). An anisopteran second instar is meant when discussing

any species throughout the following text, unless stated otherwise.

How to distinguish an anisopteran second instar from those in other

insect orders, the suborder Zygoptera, and other instars is given at

the beginning of the morphology section. The authors of most species

names are given in Tables 1 and 2; the authors of species not in the

tables are given at their first usage.

Scope of Species Coverage

About 109 species of Anisoptera breed in Florida waters. Anax

amazili (Burmeister), Brachymesia herbida (Gundlach), Tauriphila

australis (Hagen), and Tramea walker Whitehouse have been collected

in Florida but most likely are vagrants to the state. I was able

to hatch eggs from 65 species of Florida Anisoptera, listed in

Table 1. Second larval instars of 3 other species have been described

in the literature, namely Epicordulia princeps (Hagen), Libellula

Table 1. Species of larval anisopteran second instars examined.
The number of females from which larvae were preserved, and
the general locality where the females were collected are
given in the right hand columns. An H after the species
name indicates that the second instar bears epicranial
tubercles or horns on the head.

Species Number Geographic
of Broods Area

Florida Species

Tachopteryx thoreyi (Hagen) 1 Florida

Anax junius (Drury) 7 Florida
A. longipes Hagen 1 Florida
Coryphaeschna ingens (Rambur) 2 Florida
Epiaeschna heros (Fabricius) H 5 Florida
Gomphaeschna furcillata (Say) 1 Florida
Nasiaeschna pentacantha (Rambur) H 1 Florida

Aphylla williamsoni (Gloyd) H 5 Florida
Arigomphus pallidus (Rambur) H 4 Florida
Gomphus (Gomphus) australis Needham 1 Florida
G. cavillaris Needham 3 Florida
G. diminutus Needham 1 Florida
G. exilis Selys 1 Georgia
G. lividus Selys 1 Georgia
G. minutus Rambur 6 Florida
Gomphus (Stylurus) laurae
Williamson 1 Florida
G. plagiatus Selys 1 Florida
G. townesi Gloyd 1 Florida
Iagenius brevistylus Selys H 1 Quebec
Progomphus obscurus (Rambur) 2 Florida

Cordulegaster sayi Selys 1 Florida

Macromia taeniolata Rambur H 1 Florida

Table 1--continued.

Species Number Geographic
of Broods Area

Florida Species--continued.

Helocordulia selysii (Hagen) H

Neurocordulia virginiensis Davis
Somatochlora calverti
Williamson and Gloyd
S. filosa (Hagen)
S. linearis (Hagen)
S. provocans Calvert
S. tenebrosa (Say)
Tetragoneuria cynosura (Say) H
T. sepia Gloyd H
T. stella Williamson H

Brachymesia furcata (Hagen) H
B. gravida (Calvert) H
Celithemis amanda (Hagen) H
C. bertha Williamson H
C. elisa (Hagen) H
C. eponina (Drury) H
C. fasciata Kirby H
C. ornata (Rambur) H
Dythemis velox Hagen
Erythemis simplicicollis (Say)
Erythrodiplax berenice (Drury)
E. minuscule (Rambur)
Ladona deplanata (Rambur)
Lepthemia vesiculosa (Fabricius)
Libellula auripennis Burmeister
L. axilena Westwood
L. flavida Rambur
L. incesta Hagen
L. needhami Westfall
L. semifasciata Burmeister
L. vibrans Fabricius
Miathyria marcella (Selys)
Nannothemis bella (Uhler)
Orthemis ferruginea (Fabricius)

2 Florida,
South Carolina
2 Florida

Florida, Georgia

Florida, Georgia

Table 1--continued.

Species Number Geographic
of Broods Area

Florida Species--continued.

Pachydiplax longipennis (Burmeister)
Pantala flavescens (Fabricius)
P. hymenaea (Say)
Perithemis tenera (Say) H
Plathemis lydia (Drury)
Sympetrum corruptum (Hagen)
S. vicinum (Hagen) H
Tramea carolina (Linnaeus)
T. lacerata Hagen

Non-Florida Species

Aeshna multicolor Hagen

Gomphus (Gomphus) kurilis Hagen)
G. militaris Hagen
Gomphus (Gomphurus) consanguis Selys
G. rogersi Gloyd
Octogomphus specularis (Hagen)

Neocordulia n. sp.
Tetragoneuria semiaquea (Burmeister)

Belonia croceipennis (Selys)
B. saturata (Uhler)
Dythemis nigrescens Calvert
Erythemis collocata (Hagen)
Erythrodiplax connata (Burmeister)
E. funerea (Hagen)
Leucorrhinia frigida Hagen H
Libellula cyanea Fabricius
L. quadrimaculata Linnaeus
Micrathyria didyma (Selys)
M. hageni Kirby

Florida, Mexico
Florida, California

1 California


1 Panama
H 2 South Carolina

1 Texas
1 California
1 Mexico
1 California
1 Mexico
2 Mexico
1 Quebec
2 Georgia
1 California
1 Mexico
2 Mexico


Table 1-continued.

Species Number of Geographic
Broods Area

Non-Florida Species-continued.

Orthemis levis Calvert 1 Mexico
Paltothemis lineatipes Karsh 1 California
Perithemis intense Kirby H 3 Mexico
P. domitia (Drury) H 1 Mexico
Pseudoleon superbus (Hagen) 1 Mexico
Sympetrum illotum (Kagen) 1 California
S. internum Montgomery 1 Quebec
S. obtrusum (Hagen) 4 Quebec
S. semicinctum (Say) 3 Quebec

pulchella Drury, and Sympetrum ambiguum (Rambur). Of the 109 Florida

resident species, 27 are restricted to the panhandle, 11 are restricted

to the tip of the peninsula south of Lake Okeechobee, and 71 occur

in the northern 2/3 of the peninsula. Thus this study includes 68/109

or 62% of the species of Florida Anisoptera, which incorporates all

7 families and 35/45 or 78% of the genera. The coverage of northern

peninsula species is better----52/71 or 73% of the species and 31/37

or 84% of the genera.

I also inspected 28 species not found in Florida to obtain a

better idea of the range of morphological variation possible. These

species also are listed in Table 1 and are discussed in a separate


With caution, the results of this study can be applied to the non-

mountainous parts of the southeastern coastal states from Louisiana

to South Carolina. The coverage of species for this area is 70/120

or 58%, encompassing 35/45 or 78% of the genera.

Scope of Morphological Knowledge of Anisopteran Second Instars

All of the figures of anisopteran second instars which I could

locate in the literature are listed in Table 2. For the sake of

completeness figures of larval first instars also are listed. Some

references may have been overlooked, primarily because titles often

do not indicate that early instars are described. No larval second

instars of the Cordulegastridae or of the Australian Synthemidae

have been illustrated. All of the instars have not been described

Table 2. References to illustrations of anisopteran first and second
instars. In the Structure Illustrated column, a ? to the
left of the name of the structure means that there is
some doubt about the species, a ? to the right of the name
indicates some doubt about the instar. Figures of the first
instar and its parts are listed first under each species.
In the Figure Type column, L = line drawing, B&W = black and
white photograph, C = color photograph. In the Page or Plate
column, the page number of the illustration is given where
possible, plate numbers are preceded by P1. An H after the
species name indicates that the second instar bears epicranial
tubercles or horns.

Species Structure Figure Page or Reference
Illustrated Type Plate

Tanypteryx hageni Selys

T. pryeri Selys

Uropetala carovei White

Aeshna isosceles (Muller)

A. mixta Latrielle






Trident Setae


L 227 Svihla (1959)



Ando (1962)
Ando and
Miyakawa (1969)

Wolfe (1953)

L 99 Robert (1936)
L P1 15 Robert (1958)

L 80 Robert (1958)
L 230 Munchberg
L 135 Gardner (1950a)

L 135
L 135
L 80
B&W 14,15

3&W Pl 28

Robert (1958)
Ishida (1976)

Table 2--continued.

Species Structure Figure Page or Reference
Illustrated Type Plate

Aeshna viridis Eversmann

Anax imperator Leach

A. junius (Drury)

A. parthenope (Selys)

A. strenuus Hagen

Basiaeschna janata (Say)

H Second


First Labium


First Eye


P1 15
P1 1

Munchberg (1930)
Schiemenz (1953)
Schiemenz (1954)

Robert (1939)
Robert (1958)
Portmann (1921)
Robert (1939)

Corbet (1955)

Pl 1,15 Robert (1958)
61 Corbet (1963)

Pl 4 Butler (1904)
471 Needham and
Betten (1901)
P1 4 Butler (1904)
PI 1 Calvert (1934)
PI 1
Pl 2

P1 15

First Exuviae L
Second L

Second Labium? L

Brachytron pratense (Muller)Hr Second

Ando (1957)
Ando (1962)
Robert (1958)
Munchberg (1932c)
Inoue (1979a)

Williams (1936)

Pl 4 Butler (1904)

229 Munchberg (1930)
42 Schiemenz (1953)
182 Schiemenz (1954)

Table 2--continued.

Species Structure Figure Page or Reference
Illustrated Type Plate

Gomphaeschna furcillata

Hemianax papuensis

Egg Burster
Abdomen 10


Polycanthagyna melanictera First

Gomphus (Gomphus)
graslinellus Walsh

G. spicatus Hagen

G. (Stylurus) annulatus

Lestinogomphus africanus

Ophiogomphus serpentinus

Epophthalmia vittata
sundana Lieftinck H


Second Labium L




Thorax Seta

Kennedy (1936)

Tillyard (1917)
Tillyard (1968)
Tillyard (1917)
Tillyard (1968)

L 71 Ando (1962)

Needham and
Heywood (1929)
Needham and
Westfall (1955)

P1 2 Butler (1904)

L 35 Inoue (1979b)

L 15 Gambles and
L 15 Gardner (1960)

L 731 Munchberg (1932b)

Lieftinck (1931)

Corbet (1963)

Table 2--continued.

Species Structure Figure Page or Reference
Illustrated Type Plate

Epicordulia princeps

H Labium

Epitheca bimaculata
(Charpentier) H

E. marginata (Selys) H

Oxygastra curtisii (Dale)

Somatochlora kennedyi

S. metallica (Van der

S. viridiaenea Uhler H







L 244
L 244

P1 1
P1 33
PI 33
P1 1
P1 2
P1 33
P1 33

Wilson (1917)

Heymons (1896)
Robert (1936)
Robert (1958)

Heymons (1896)

Robert (1936)
Robert (1958)

Sonehara (1968a)

B&W 23 Sonehara (1972)
C P1 33 Ishida (1976)

L 35
L 39

PI 17
PI 17
PI 17

Fraser (1951)

Walker (1925)

L 281 Munchberg (1932a)

Miyakawa (1971)

Tetragoneuria canis

T. spinigera Selys

Second Head
H Labium

a First





L 93 Kormondy (1955)
L 43 Kormondy (1959)

Table 2--continued.

Species Structure Figure Page or Reference
Illustrated Type Plate

Diplacodes haematodes

Erythemis simplicicollis

Leucorrhinia dubia
(Van der Linden)

L. intacta (Hagen)

Libellula depressa

L. fulva Muller

L. luctuosa Burmeister

L. pulchella Drury


L 72 Tillyard (1917)

?Anal Append.
Abdomen 9+10

Second Labium
Anal Append.






L 242
L 242

Wilson (1917)

Needham and
Heywood (1929)
Bick (1941)

Gardner (1953a)
Prenn (1929)

Gardner (1953a)

Wilson (1917)

Gardner (1953b)
Portmann (1921)
Gardner (1953b)

L P1 15 Robert (1958)

L 239
L 239

L 240
L 240

Wilson (1917)

Wilson (1917)

L. luctuosa X L. pulchella Second

L 241 Wilson (1917)

Lyriothemis pachygastra

Nesogonia blackburni

Second Labium L
Antenna L


Miyakawa (1970)

L 291 Williams (1936)

Table 2--continued.

Species Structure Figure Page or Reference
Illustrated Type Plate

Orthetrum albistylum

0. cancellatum (Linnaeus)

0. poecilops Ris

Pachydiplax longipennis

Pantala flavescens

Plathemis lydia (Drury)

Pseudothemis zonata
(Burmeister) K

Sympetrum danae (Sulzer)

S. fonscolombii Selys

S. frequens Selys

S. meridionale (Selys)

S. nigrifemur (Selys)

Second Eye




Abdomen 10


Abdomen 9+10


Tihial Comb

Second Eye

First Exuviae
First Exuviae



P1 15











Ando (1957)
Bilek (1962)

Robert (1958)

Sawano (1966)

Wilson (1917)

Lamb (1925)

Wilson (1917)

Miyakawa (1969)

Gardner (1951a)

Gardner (1951b)

Ando (1957)

Aguesse (1959)

Aguesse (1968)
Aguesse (1959)

Gardner (1962)

Table 2--continued.

Species Structure Figure Page or Reference
Illustrated Type Plate

Sympetrum obtrusum

S. rubicundulum (Say)

S. sanguineum Muller

First L
Second Labium L
Antenna L
Labium L

Second Labium L


Tai (1967)

Trottier (1969)

458 Trottier (1969)

L 24 Gardner (1950b)

S. striolatum (Charpentier) First

S. vicinum (Hagen) .

Tramea lacerata Hagen

Trithemis annulata
scortecii Nielsen

First Labium
Second Head

Second Ligula L
Palp L

Second Palp L

Gardner (1950c)
Corbet (1951)
Schiemenz (1953)
Schiemenz (1954)
Lucas (1899)
Gardner (1950c)

Corbet (1951)
Schiemenz (1953)
Gardner (1954)
Schiemenz (1954)

Tai (1967)

Trottier (1969)

Bick (1951)

83 El Rayah and
El Din Abu Shama

Zyxomma petiolatum Rambur H Second

L 78 Corbet (1963)


for any species in these families or for any species of Gomphidae or

Macromiidae. All or part of the second larval instar of 22 of the Nearctic

species have been illustrated. Second larval instars of 6 other Nearctic

species have been described but not illustrated. These are Aeshna

juncea (Linneaus) described by Robert (1958), A. tuberculifera Walker

by Lincoln (1940), Somatochlora filosa by Dunkle (1977), Tetragoneuria

cynosura by Kormondy (1955,1959), Sympetrum ambiguum by Tai (1967), and

S. semicinctum by Tai (1967). Thus 28/287 or 10% of the Nearctic

species have had the second instar characterized in some degree.

Only 14/287 or 5% of the Nearctic species have had all the instars

described. These are Aeshna juncea described by Robert (1958),

A. tuberculifera by Lincoln (1940), Anax junius by Calvert (1934) and

Macklin (1963b), Somatochlora filosa by Dunkle (1977), Tetragoneuria

cynosura and T. spinigera by Kormondy (1955,1959), Erythemis simplicicollis

by Bick (1941), Pantala flavescens by Lamb (1925,1929), Sympetrum

danae by Gardner (1951a) and Robert (1958), S. vicinum by Nevin (1929)

and Tai (1967), and S. ambiguum, S. obtrusum, S. rubicundulum, and

S. semicinctum by Tai (1967). Three other Nearctic species have been

reared from egg to adult but the instars were not described. These

are Gynacantha nervosa Rambur reared by Williams (1937), Nannothemis

bella by Calvert (1929), and Pachydiplax longipennis by Macklin (1963a).

Of the 109 Florida species, 15 or 14% have had the second instar partially

or fully described, and 7/109 or 6% have had all the instars delineated.

These species are mentioned in the descriptions section of this study.

I have reared or partially reared a number of other species from the

egg which are also mentioned in the species description section.


Obtaining Fertile Anisoptera Eggs

Anisoptera eggs are fertilized with stored sperm released

from the female's spermatheca as the eggs are laid. No parthenogenetic

or ovoviviparous species are known. All of my many attempts to

fertilize Anisoptera eggs dissected from a female with sperm from the

same or a different species in vitro were failures. The major

problem with these experiments seemed to be lack of sperm motility.

F. C. Johnson (personal communication) observed motility in sperm

taken from Perithemis tenera, yet eggs fertilized with these sperm

did not complete embryonic development.

Various methods of obtaining eggs from endophytic Anisoptera,

the Aeshnidae and Petaluridae, have been mentioned in the literature.

Needham and Westfall (1955) proposed placing a fresh Typha stem at

a slant and a little in front of a patch of erect emergent stems, and

changing the stalk every day. A problem with this method is that one

might not be sure of which species oviposited in the stem. Another

method is to watch a female oviposit, then collect the object or soil

sample containing the eggs. One disadvantage of this method is that

some other female of the same or a different species may have previously

oviposited at that spot. Another disadvantage is that a large amount

of time is sometimes needed to find the eggs in the collected material.


Gardner and MacNeill (1952) and Ando (1962) allowed endophytic

species to oviposit in soft stems in a container in the laboratory.

The former used a 100 watt incandescent lamp to warm the container.

I have found white, wet, paper toweling on the floor of a container

more convenient because the eggs can easily be seen. The sides of the

container, and for some species, the top, should be slippery so that

the female must rest on the wet toweling. I used a 4 liter plastic

jug with one side cut out and loosely covered with a plastic bag or

netting. This is a modification of a method developed by Wilbur

(1945). Some endophytic species will not oviposit under these conditions,

even if the female is captured while ovipositing, for example

Coryphaeschna ingens. Other species were reluctant to oviposit but

finally did so after several females were tried, for example Tachopteryx

thoreyi. Anax oviposits readily in captivity and Obana and Inoue (1972)

have a photograph of A. panybeus Hagen ovipositing in a piece of paper

held in the hand. Kubota (1978) used a 10 volt 60 cycle electric

current to induce the release of more than 5 eggs in 70% of the

Zygoptera he worked with, but I was unable to obtain anisopteran eggs

by using this method. No method has been found to induce Cordulegastridae

to oviposit in captivity.

Exophytic species generally release eggs readily into a container

of water if the female was caught while ovipositing, and the abdomen

is tapped to the water surface. Often more eggs are released if only

one pair of wings is held above the back of the dragonfly and the other

pair allowed to move. Lieftinck (1933) obtained more eggs by loosely

holding a female's thorax between his fingers and allowing both pairs of

wings to move. Gentle squeezing of the abdomen often starts a female

ovipositing, and Gardner and MacNeill (1952) suggested stroking the dorsal

surface of the abdomen with a brush. As with the endophytic species,

some exophytic Anisoptera are very reluctant to release eggs when

captured, for example Aphylla and the Macromiidae. Aphylla williamsoni

released eggs only after considerable squeezing of the abdomen. One

Macromia taeniolata female oviposited after I employed the platform

method of Gardner and MacNeill (1952). This method involves pinning

the female's wings to a platform over a dish of water so that her

abdomen dips into the water as she struggles. It should be mentioned

that Lieftinck (1931) easily obtained eggs from the macromiid

Epophthalmia vittata by capturing an ovipositing female, loosely

holding the insect's thorax, and regularly stripping the end of its

abdomen against a piece of soft carton in a bottle of water. Armstrong

(1958) obtained eggs from Hemicordulia australiae (Rambur) by merely

providing a petri dish of water in the bottom of a 38 X 38 cm cage.

It is interesting to speculate that some of the exophytic Anisoptera

may voluntarily release eggs, perhaps as a "squirt," with each tap to

the water surface. Someone should examine the internal anatomy of

these species to determine if such a muscular mechanism exists.

Hatching Anisoptera Eggs

In my experience, eggs hatched best when oviposited into

aged tap water. When water from the wild was used the eggs were

much more likely to mold, especially if many unfertilized eggs were

present. Krull (1929) also found that eggs hatched best in clean

water, but Tillyard (1917) got better results in very dirty water.

Perhaps if enough of a grazing fauna is present, the growth of mold

can be kept in check, hut it is certainly more convenient for obser-

vation if clean water is used. I did not find it necessary to aerate

the water during incubation, even for stream species. Obana and

Inoue (1972) aerated the water with the floating liverwort Riccia, but

presumably green plants used in this way should be continuously


Anisoptera eggs hatch in 5-50 days, depending on species and

temperature, unless diapause intervenes. Egg diapause is known in

Aeshna, Somatochlora, and Sympetrum. The longest hatching time

known to me is 221 days in Aeshna nigroflava Martin (Ando,1962).

Preserving and Preparing Specimens

Larval second instars should be allowed to age for about a day

to develop their color pattern and harden the exoskeleton. Since

alcohol fades the color pattern, the color pattern should be des-

cribed before placing specimens in alcohol. I found that 83% ethyl

alcohol preserved specimens much better than 70% isopropyl alcohol.

Larvae should be preserved at 1 or 2 days of age after hatching

to avoid their becoming pharate third instars, which obscures the

second instar characteristics.

The following procedure is recommended for rapid examination

of anisopteran second instars. If the investigator wishes, he or she

may examine the specimens under a dissecting microscope, or in a

depression slide under a compound microscope, until he/she finds

that removal of the labium is necessary.

1. Describe the color pattern before preservation. Alter-

nating light and dark backgrounds under the specimen allows

different parts of the color pattern to be seen more

clearly under a dissecting microscope.

2. Measure head width and total body length, using an ocular

micrometer in a dissecting microscope.

3. Look for horns, dorsal abdominal spines, and ventral abdom-

inal spines while rolling the specimen on its side in a

dish of alcohol under the high magnification of a dissecting

microscope. Note whether the palps of the labium cup

dorsally in front of the face or lie in the same plane

as the prementum.

4. Arrange the specimen on its side in a drop of alcohol on

a microscope slide with labium extended and legs and anten-

nae pulled away from the labium. An eyedropper of alcohol

should be ready to add alcohol if the specimen begins to

dry out.

5. Cut the labium through the postmentum, using the tip of

a small, sharp scalpel.

6. Arrange the labium in the center of the slide, dorsal

side up. Arrange the body dorsal side up near the labium,

with legs and antennae extended.

7. Flow a fresh drop of alcohol onto the slide from the side

of the specimen. Quickly place one edge of a coverslip

near the specimen, and lower it gradually to force out air

bubbles. Centering the specimen under the coverslip and

centering the coverslip on the slide allow the specimen

to be located more easily under the compound microscope.

The body of the specimen will be somewhat wrinkled and

distorted, but the labial parts, antennae, and legs are

in one plane for accurate observation and measurement.

8. Blot away excess alcohol from the edge of the coverslip,

and seal the edges of the coverslip with a permanent

mounting medium. Some of the mounting medium should

overlap onto the top of the coverslip along its entire

margin. The slide should be handled and stored horizontally

until the mounting medium has hardened for several days.

The result is a semi-permanent slide which dries out in a

few days or weeks. Thus observations should be made soon

after preparation. Some features can be seen on a dry

specimen, however, and a slide can be partially or entirely

restored by scraping away some of the mounting medium, and

allowing fresh alcohol to flow under the coverslip.


9. Label the slide.

10. The specimen is most easily located under a compound

microscope if the objective lens is swung out of the way,

the specimen centered in the hole of the stage, and the

objective lens then clicked back into position.


Morphology of Anisopteran Second Instars

In order to use the keys given later, one must ascertain that

the specimen to be identified is actually an anisopteran second instar.

Anisopterans are insects which have 2 antennae, 3 major body divisions,

and 6 legs. As members of the order Odonata, they are distinguished

from all other insects by the enlarged, grasping labium of the larvae,

shown in Figure 1. Larvae of the donate suborder Anisoptera have

3 pointed appendages at the tip of the abdomen. The length of these

appendages is less than or equal to the combined length of the

posterior 3 abdominal segments. In the suborder Zygoptera, these

appendages are nearly as long, or longer, than the abdomen. The

anisopteran first instar has all of its appendages directed posteriorly,

and is not able to walk. The anisopteran second instar is about 1-2 mm

long in the exophytic families, 2-3 mm long in the Petaluridae and

Aeshnidae. With some possible exceptions to be discussed later,

anisopteran second instars have 3-segmented antennae, 1-segmented

tarsi, no wing pads, no cerci, a maximum of 1 major palpal seta on

each palp, and no major premental setae. Anisopteran third instars

are about 26% larger than the second instar (Calvert,1929), and often

have more antennal segments, tarsal segments, and major palpal setae.

The ways in which certain structures of some species change with growth

are given in Table 3 and the species descriptions.

Antennae. The 3 segments of the antennae are known from the base

toward the tip as the scape, pedicel, and flagellum. The pedicel is

generally longer than the scape, and the flagellum is longer than the

other 2 segments taken together. The scape has an enlarged seta on the

medial side in all the families except Gomphidae.

Fraser (1951) reported that Oxygastra curtisii had 4-segmented

antennae, but his figures also show 2- or 3-segmented tarsi, 2 major

palpal setae, and 2 major premental setae. If one compares these numbers

with the growth changes of other Corduliidae in Table 3, it appears that

Fraser was describing instar 4 when he thought he had instar 2.

Lamb (1925) stated that Pantala flavescens had 4-segmented antennae,

but all specimens of this species I have seen had 3-segmented

antennae. Lamb may have seen the pharate third instar within the

exuviae of the second. Gardner and MacNeill (1952) recommended examining

the exuviae of an instar to correctly determine the number of antenna

and tarsal segments. Munchberg (1932b) claimed that the antennae of

Ophiogomphus serpentinus and Gomphus flavipes (Charpentier) were

2-segmented. I suspect that the antennae of these species are actually

3-segmented, because in Gomphidae the antennae slope ventrally, the

scape is short, and the scape may be partly telescoped into the head.

The dark stripes Munchberg described on the dorsal thorax and abdomen

of 0. serpentinus are probably thick setae, indicating that he did not

examine this species in lateral view. Wilson (1917) in his descriptions

of several Corduliidae and Libellulidae thought that the tip of the

Table 3. Changes in the number of antenna and tarsal segments, and
the number of major labial setae, during instars 2 to 4 of
some Florida Anisoptera. SWD refers to data from the present

Species Antennae Tarsi Major Major Reference
Palpal Premental
Setae Setae
234 2 3 4 234 23 4

Tachopteryx thoreyi

3 3 4-5 1 2 2

Gomphaeschna furcillata 3 4 4

Nasiaeschna pentacantha 3 3 4
Epiaeschna heros 3 3 4
Coryphaeschna ingens 3 3 4
Anax junius 3 4 4
A. longipes 3 3 3-4

Arigomphus pallidus
Gomphus minutus
Progomphus obscurus

Cordulegaster sayi

Macromia taeniolata

Helocordulia selysii
Somatochlora calverti
S. filosa
S. provocans
Tetragoneuria cynosura

1 1 1-2

Kennedy (1936),
Calvert (1934)

3 3 5 1 2 2 0 1 2 0 1 3 SWD

3 3 3 1 1 1 1 12 0 1 3 SWD

33 112
3 3 4-5 1 1 2

1 1 2 01 1
112 0 1 3

Dunkle (1977)


Table 3--continued.

Species Antennae Tarsi Major Major Reference
Palpal Premental
Setae Setae
2 3 4 2 3 4 2 3 4 23 4

Brachymesia gravida
Erythemis simplicicollis
Ladona deplanata
Orthemis ferruginea
Pantala flavescens

Sympetrum ambiguum

S. vicinum
Tramea lacerata

3 3 4 1 1 11 1 2 0 1 2 SWD
3 3 4 1 1 1 1 2 0 1 3 Bick (1941)
3 3 4 1 1 1 1 1 2 0 1 3 SWD
3 3 4 1 1 1 1 1 2 0 1 3 SWD
3 3 4-5 1 1 1 0-1 1 4 0 2 4 Lamb (1925),
Miyakawa (1977)
3 3 4 1 1 1 1 2 3 0 1 4 Tai (1967),
Trottier (1969)
3 3 4 1 1 1 1 2 0 1 3-4 Tai (1967)
3 3 4 1 1 1 1 1 2 0-1 1 3-4 Bick (1951)

antennal flagellum was the third segment. Thus his second "joint"

or segment is the proximal part of the flagellum, his "first joint"

or "basal joint" is the pedicel, and his "base" is the scape.

Labium. The terminology used for labial parts is shown in

Figure 1. Minor Palpal Setae numbers 1 and 2 were present in nearly

all species I examined, but showed little variation that could be

used as key characters. Minor Premental Setae 6,7, and 8 were

constantly present in the Macromiidae, Corduliidae, and Libellulidae,

and some species of other families. These setae showed differences in

position, but the differences seemed to depend at least in part on how

the labium was flattened on a slide. The other Minor Palpal Setae and

Minor Premental Setae often required extremely critical focus and

lighting to see, and were not constantly present. The Ligular Setae

also demanded critical focusing to observe. The Dorsal Ligular Setae

are usually lateral as well as dorsal to the Ventral Ligular Setae,

but the relative positions of the 2 pairs of Ligular Setae appeared

to be determined by how the labium was flattened on a slide. The best

taxonomic characters displayed by the labium were the palpal teeth and

the condition of the ligula. The Ligula is a convenient term for the

antero-medial area of the prementum. It may have an anterior projection

or an open or closed medial cleft.

The numbers of labial setae and ligular teeth in the remainder of

the text refer to the number on either the right or left side unless

stated otherwise. Petaluridae, Aeshnidae, and Gomphidae have a flat

labium with no major labial setae in any instar. Macromiidae, Corduliidae,

Figure 1. Composite labium of anisopteran second instars, identifying
terms used in the text. No single species has all the
features shown and few if any species normally have Major
Premental Setae in the second instar. Numbers 1-5
identify Minor Palpal Setae; numbers 6-12 identify Minor
Premental Setae. The Palps shown have 3 pointed teeth,
2 rounded teeth, and a crenate antero-medial corner.
The Ligula has a Ligular Projection with 3 teeth on each side,
and both the Ligular Projection and the Ligula have an
open cleft.

and Libellulidae have a cupped labium with usually 1 major palpal seta

in the second instar, more major palpal setae plus major premental

setae in later instars. Cordulegastridae have a cupped labium without

major labial setae in the second instar, both major palpal setae and

major premental setae in later instars.

A few authors have recorded the presence of major premental

setae in the second instar. Gardner (1951b) stated that Sympetrum

fonscolombii has 1 major premental seta. Bick (1951) stated that

Tramea lacerata sometimes has 1 major premental seta in the second

instar, but all the specimens I examined lacked major premental setae.

Lieftinck (1933,p 413) said that second instars of Procordulia artemis

Lieftinck have a "Labium with two mental setae, the outermost much

shorter than the inner, the latter vestigial. . This may mean

that the setae he saw were not major setae.

Several writers, for example Lamb (1925), have noted that

major palpal setae may be lacking from 1 or both palps in individuals

of species that normally have a major palpal seta on each palp. The

characteristic labia are shown for 5 families of Anisoptera in Figure

2. The labia of Corduliidae and Libellulidae are like the labium

of Macromiidae.

Eyes.Anisopteran second instars lack ocelli but have a pair of

compound eyes. Ando (1957,1962) found that the number of ommatidia

in each compound eye of the 22 species he examined was constant

within a species. The numbers of ommatidia he found within families

were 7 in Petaluridae, 170-270 in Aeshnidae, 7 in Gomphidae,

7 in Cordulegastridae, 7 in Macromiidae, 7-10 in Corduliidae, and

7-19 in Libellulidae. Unfortunately I was unable to accurately

count the ommatidia in my specimens with either bright field or

phase contrast microscopy, and so could not use ommatidial number

as a key character.

Epicranial Tubercles or Korns. Some species of Anisoptera

have 1 or 2 pairs of outgrowths of the head exoskeleton which have

the position, but of course not the structure, of mammalian horns.

For simplicity, these outgrowths are referred to as horns if they

are as long or longer than their width at the base, or as tubercles

if they are shorter than their basal width. The distribution of

horns within the Anisoptera is discussed in a later section.

Thorax. The thorax, as in other insects, has 3 segments, which

are from anterior to posterior the prothorax, mesothorax, and meta-

thorax. A pair of setae on 1 or more of these segments may be enlarged

and be a useful taxonomic character. The legs consist of 6 segments,

which from the base distally are the coxa, proximal trochanter, distal

trochanter, femur, tibia, and tarsus. The tarsus becomes 3-segmented

in later instars. The tip of the tarsus always bears 2 equal claws,

unless these are lost by accident.

The setae on the underside of the distal end of the tibiae are

spiniform digging setae in the Petaluridae, Cordulegastridae, and

some Gomphidae. These setae are branched in one plane with 3-7

divisions, forming tibial combs, in the Aeshnidae, Macromiidae,

Corduliidae, and Libellulidae. The number of comb setae is best

seen in ventral view. Some setae on the underside of the tarsi in

the Aeshnidae are branched, and some are serrated along the most

ventral side, forming tarsal combs. MacNeill (1967) discussed tibial

and tarsal combs-of several anisopteran families.

Abdomen. The abdomen consists of 10 segments in all instars,

numbered from the base toward the posterior end as segments 1 to 10.

Posterior to segment 10 are 3 short, pointed, anal appendages.

These comprise a dorsal epiproct and 2 ventral paraprocts. The

2 cerci, lateral in position, do not appear until several instars

have passed. Medial to the anal appendages are 2 flap-like anal

valves which may be as long as the paraprocts in the second instar,

but become hidden by the anal appendages in later instars.

The dorsal and lateral abdominal spines, so useful in the

taxonomy of late instars, are generally lacking in the second instar.

Aeshnidae and Gomphidae have lateral abdominal spines. Dorsal

abdominal spines are known to occur only in some species of Gomphidae.

Arigomphus pallidus has ventral thoracic and abdominal spines, and to

my knowledge, it is the only anisopteran to possess such spines.

A large mass of yolk fills the midgut. This is often enough to

sustain the larvae to the third instar. According to Johannsen and

Butt (1941), the midgut lumen is not open in Plathemis lydia until

the end of the second instar, and food eaten before that time

accumulates in the posterior end of the foregut. The rectal gills

form an opague mass in the posterior end of the abdomen.

Size. Body size is not generally a useful character for separ-

ating species or genera of anisopteran second instars, but size is

useful in separating instars. Total length is measured in dorsal

view from the base of the lahrum to the tip of the epiproct, and

thus excludes the antennae. Head width is the maximum width, usually

across the eyes, and excludes lateral horns. Head width is more

reliable than total length because the abdominal segments can tele-

scope. Specimens in alcohol are extended, and thus longer than

living specimens. The measurements given in this study are taken

from specimens in alcohol.

Keys to Florida Anisopteran Second Instars

In the following keys, I have used the characters which are

easiest to see first. In many cases, identifications are possible

without detaching the labium. Where color pattern is used, I have

also tried to include one or more structural characters. Major

qualifications in the use of the keys are stated at the beginning

of each key, or at the appropriate place within the key. Number of

structures given is the number on the left or right side unless

otherwise stated. Left margin numbers in parentheses indicate the

previous couplet choice which led to that point and allow the

user to verify the characters of a group by quickly backtracking

through the key.

Key to Families

lA. Mid-dorsal or mid-ventral spines present on some segments of

the abdomen (Figures 6A,6B) ................. Gomphidae in part

1B. No mid-dorsal or mid-ventral abdominal spines present ....... 2

2A.(1B) Lateral spines present at least on abdominal segment 9,

labial palps lie in nearly the same plane as the prementum .. 3

2B. No lateral abdominal spines present, labial palps flared

dorsally (except in Petaluridae) to lie nearly perpendicular

to the plane of the prementum ............................... 4

3A.(2A) Body with a conspicuous color pattern; eyes usually

large, covering about half of the sides of the head (1/3 in

Gomphaeschna); tibial and tarsal combs present; ligular cleft

present but closed (Figure 2C) .................... Aeshnidae

3B. Body uniformly gray or brown; eyes small, covering about 1/3

of the sides of the head; no tibial combs, tarsal combs, or

ligular cleft present (Figure 2D) ........... Gomphidae in part

4A. (2B) Labial palps lie in nearly the same plane as the

prementum; 4 flat, lanceolate, digging setae on the under-

side of the distal end of each tibia (Figure 6C); local, in

spring seepages in deciduous forest in north Florida ..........


4B. Labial palps nearly perpendicular to plane of prementum,

tibial combs or tapered setae present on distal ends of

tibiae (Figure 6D); various habitats ....................... 5

5A.(4B) No tibial combs and no major palpal setae present in the

second instar; ligula projecting anteriorly, the projection

widely V-cleft (Figure 2B); habitat streams in north Florida

(head shown in Figure 7B) ......................... Cordulegastridae

5B. Tibial combs and 1 major palpal seta present; ligular projection

if present small and bifid (Figure 2E); habitats various....6

6A. (5B) Head with a pair of large horns, each tipped with a flat,

scale-like seta (Figure 6G); sides of the thorax with a short,

robust seta above each leg base ................. Macromiidae

6B. Horns, if present, tipped with a tapered or brush-like seta

(Figure 6H); setae above leg bases, if present, are tapered...7

7A.(6B) Palps with antero-medial corner crenate, ligula with a

bifid-notched projection (Figure 3) ............. Corduliidae

For the convenience of the user, some genera of Corduliidae

and Libellulidae may be identified without removing the labium

by going directly to the combined key to these families from

this point.

7B. Palps with antero-medial corner slightly if at all crenulate;

ligula without a projection, but 1-3 teeth are sometimes present

(Figure 3) .................................... Libellulidae

Key to Aeshnidae

Genera Not Examined:

Basiaeschna janata -- streams in the Florida panhandle

Boyeria vinosa -- streams

Gynacantha nervosa Florida peninsula, temporary forest ponds

Triacanthagyna trifida (Rambur) -- Florida peninsula, probably

temporary forest ponds

lA. Head with a pair of long, lateral horns behind the eyes which

extend laterally farther than the eyes; vertex with a second

pair of short, forward-slanting horns; beginning with the

third instar dorsal abdominal spines are present (Figure 7A)...

Nasiaeschna pentacantha

IB. Head with only one pair of horns, or no horns; never any

dorsal abdominal spines ................................... 2

2A.(1B) Head with one pair of postero-lateral conical horns

which are about as high as wide at the base .. Epiaeschna heros

2B. No horns on head ........................................... 3

3A. (2B) Lateral spines on abdominal segment 9 only; antennae as

long as head; eyes small, covering about 1/3 of the sides

of the head .................................... Gomphaeschna

3B. Lateral abdominal spines on segments 7-9; antennae shorter

than head; eyes large, covering about 1/2 of the sides of

the head ................................................... 4

4A.(3B) Mid-dorsal red stripe from prothorax to posterior edge

of abdominal segment 4; antennae pale, with distal half of

flagellum bent laterally, narrowed, and darkened; frons with

a lengthwise ridge; abdominal segment 7 gray, with a mid-

dorsal and lateral pale spots ............ Coryphaeschna ingens

4B. No red markings; antennae not as above; frons bulging but not

ridged; abdominal segment 7 without pale spots ............. 5

5A. (4B) Large pale mid-dorsal spot on abdominal segment 8; pale

+ mark on head, with posterior arm of + mark narrow and

nearly parallel sided; abdominal tergites pigmented to their

anterior and posterior edges; medial palpal margin smooth;

5-6 ligular teeth on each side of midline; ligular setae no

longer than ligular teeth ........................ Anax junius

5B. No pale spot on 8; pale + mark on head, with posterior arm

widely divergent rearward; abdominal tergites with yellow-

brown anterior and posterior edges, giving abdomen a tiger-

banded appearance; medial palpal margin crenate; 3-4 ligular

teeth on each side with a gap in the row; a pair of ligular

setae extend beyond ligular teeth ................ Anax longipes

Key to Gomphidae

Genera Not Examined:


Erpetogomphus designatus Hagen -- Apalachicola River

1A. Prominent dorsal abdominal spines present (Figure 6B) ...... 2

1B. No dorsal abdominal spines present ........................ 4

2A.(1A) Dorsal abdominal spines present on 1 or 2 to 9; flagellum

flattened, oval in dorsal view; head with 2 pairs of horns

(Figure 7C) ........................... Hagenius brevistylus

2B. Dorsal abdominal spines on 3 to 9 or on 8 and 9; flagellum

cylindrical, pointed; head with 1 pair of horns or horns

absent .................................................. 3

3A. (2B) Head with a pair of backward slanting horns; dorsal

abdominal spines on 3 to 9 (Figure 6B).... Aphylla williamsoni

3B. Head without horns; dorsal abdominal spines on 8 and 9 .......


4A.(1B) Head with a pair of horns, each tipped with a dark brown seta

bulbous in its basal half (Figure 6F); mid-ventral spines present

on mesothorax, metathorax, and abdominal segments 2 to 8 (Figure 6A)

Arigomphus pallidus

4B. No horns on head; no ventral thoracic or abdominal spines .......

Genus Gomphus 5

5A.(4B) Setae on epiproct minute or absent; either pairs of stout

stubby setae dorsally on abdominal segments 2-9 or pairs of stout

spike-like setae on each segment from mesothorax to abdominal

segment 10 ............................... Gomphus (Stylurus)

5B. Setae on epiproct robust; no stubby dorsal abdominal setae;

dorsal spike-like setae, if present, on abdominal segments 1-9...6

6A.(5B) Abdominal segment 10 not well set off from rest of abdomen,

mid-dorsal length of segment 10 47% or less of its maximum width;

abdomen appears short, broad, and blunt in dorsal view;

burrowing hooks on distal ends of pro- and mesotibiae moderately

well developed ........Gomphus (Gomphurus) and probably

Gomphus (lylogomphus)

None of the Florida species of these subgenera were examined.

6B. Abdominal segment 10 set off from segment 9 as a breathing

siphon, its mid-dorsal length 48% or more of its maximum width;

tibial burrowing hooks poorly developed .....Gomphus (Gomphus)

Key to Gomphus (Stylurus)

Species Not Examined:

G. ivae Williamson--north Florida streams

G. potulentus Needham--panhandle streams

lA. Pairs of stout, pointed, spike-like setae dorsally on each

segment from mesothorax to abdominal segment 10 .....G. townesi

IB. No stout setae on thorax or abdominal segments 1 and 10, but stout,

blunt dorsal setae are present on abdominal segments 2-9 ....2

2A.(1B) Abdominal segments each with 3 pairs of dorsal setae, thus

each of the stubby setae is flanked by a medial and a lateral

hair-seta; a robust seta present above antenna bases; second

instar about 1.46 mm long ........................G. laurae

23. Abdominal segments 2-8 each with 2 pairs of dorsal setae, no

hair-setae medial to the stubby setae; no robust seta above

antennal bases; second instar about 1.26 mm long .....G. plagiatus

Key to Gomphus (Gomphus)

Species Not Examined:

G. hodgesi Needham--panhandle streams

G. descriptus Banks--the Florida record from Chipola Dead Lake

needs to be confirmed

lA. Head with thick blunt seta mounted on conical base nearly as tall

as wide on each rear corner; mid-dorsal length of abdominal

segment 10 68% of its basal width; habitat sand-bottom lakes....

G. australis

IB. Rear corner setae of head, if thickened, not blunt or mounted

on a high conical base; mid-dorsal length of abdominal segment 10

usually 54% or less of its basal width (62% in G. minutus);

various habitats ............................................ 2

2A. (B) Body brown; medial pairs of dorsal setae on abdominal

segments 1-9 dark and thickened, appearing black at 50X; only

3 pairs of setae on head behind level of eyes ....G. lividus

2B. Body usually gray (brown in G. exilis); medial setae on abdomen

may be thickened and darkened, but not enough to appear black

at 50X; 4 or more pairs of setae on head behind level of eyes...3

3A.(2B) Mid-dorsal length of abdominal segment 10 62% of its

basal width .................................... G. minutus

3B. Mid-dorsal length of abdominal segment 10 48-54% of its

basal width ................................................... 4


4A. (3B) Mid-dorsal length of abdominal segment 10 54% of its basal

width, appearing cylindrical; body gray; western Florida

panhandle ...................................... G. diminutus

4B. Mid-dorsal length of abdominal segment 10 48-50% of its

basal width, flattened; body gray or brown; Florida panhandle

or peninsula ............................................. 5

5A. 4B) Body brown; slow streams and lakes in the western Florida

panhandle; 6 anterior palpal teeth; 5-6 ligular teeth .........

G. exilis

5B. Body gray; sand-bottom lakes in both panhandle and peninsula;

8 anterior palpal teeth; 7 ligular teeth ...... G. cavillaris

Key to Corduliidae and Libellulidae

Genera Not Described:

Crocothemis servilia Drury -- south Florida

Idiataphe cubensis (Scudder) -- south Florida

Macrodiplax balteata (Hagen) -- primarily coastal, and marl


Tauriphila australis (Hagen) -- south Florida, may not breed

in Florida

1A. Dorsum of head with conspicuous horns ..................... 2

B1. No tubercles or horns on head ............................. 10

2A.(1A) Pairs of thick, inflated, cylindrical setae on occiput,

each segment of thorax, and each of the first 9 abdominal

segments (Figure 61) ....................... Perithemis tenera

2B. Setae on occiput, thorax, and abdomen may be thickened but

are pointed, not inflated or cylindrical .................. 3

3A.(2B) Horns tipped with a thick, brush-like seta (Figure 6H) or

hooked posteriorly at the tip; 2 setae anterior to each horn..4

3B. Horns tipped with a thin, tapered seta, rarely a slightly

brushy seta; 1 seta anterior to each horn (2 setae..in

Helocordulia and Neurocordulia) ............................ 5

4A.(3A) Horns tipped with a thick brush-seta; 6 anterior palpal

teeth (Figure 3B) ............................. Tetragoneuria

4B. Horns hooked posteriorly at the tip; 7-8 anterior palpal

teeth .................................. Epicordulia princeps

5A.(3B) Horns 2X as tall as width at base, or taller .......... 6

5B. Horns as tall as wide, or shorter ......................... 7

6A.(5A) One thick seta posterior to each horn; midgut usually

pigmented ....................................... Brachymesia

6B. Two thin setae posterior to each horn; midgut not pigmented ...

Celithemis in part

7A.(5B) Palps with 6 pointed anterior teeth; ligula with a bifid

projection (Figures 3A,3C); habitat streams ............... 9

7B. Palps with 2-4 pointed anterior teeth (Figures 4C,4D); ligula

without a projection, but sometimes 1-3 teeth present;

habitat usually still water .............................. 8

8A.(7B) Horns divergent laterally; flagellum about 59% as long

as width of head .......................... Sympetrum vicinum

8B. Horns vertical; flagellum 62-70% as long as width of head ......

Celithemis in part

9A. 7A) Major palpal seta shorter than movable hook (Figure 3C);

femora unbanded; midgut may be pigmented ....... Neurocordulia

9B. Major palpal seta longer than movable hook (Figure 3C);

femora with dark hands at 1/4 and 3/4 of their length;

midgut not pigmented .................. Helocordulia selysii

10A.(1B) Eyes large, occupying the anterior 1/2 to 2/3 of the

lateral margin of the head (Figure 7D); body dark gray;

habitat Sphagnum bogs ...................... Nannothemis bella

10B. Eyes smaller, covering approximately the anterior 1/3 of the

lateral head margin; color and habitat various............. 11

11A.(10B) Head dorsum with a large, conspicuous, pale, mid-dorsal

mark which narrows anteriorly; femora unbanded or with one

distal band ..................................... ........ 12

11B. Head dorsum without a conspicuous pale mark; femora often

with 2 dark bands, but may be unbanded or have 1 dark band.. 14

12A.(11A) Pale mid-dorsal head mark is wedge-shaped; tip and base

of flagellum dark; paraproct tip-seta about 44% as long as

paraproct; habitat salt marsh ......... Erythrodiplax berenice

12B. Pale mid-dorsal head mark is violin-shaped; flagellum

unbanded; paraproct tip-seta about 17-20% as long as paraproct;

habitat not salt marsh ................................... 13

13A.(12B) Pale mid-dorsal stripe from labrum to abdominal segment

9; anterior palpal margin with 1-3 low, pointed teeth

(Figure 4A); widespread distribution .............. Erythemis

13B. Pale mid-dorsal stripe not extending to the posterior

abdomen; anterior palpal margin with 3-5 larger, pointed

teeth (Figure 4F); south Florida ........ Lepthemis vesiculosa

14A.(11B) Femora with dark bands at 1/4 and 3/4 of their length ...15

14B. Femora unbanded, or with 1 dark distal band ...................21

15A. (14A) Read dorsum freckled with brown lateral to level of antennal

bases; antennae unbanded; abdominal segments 1-4 and 8-9 dark

brown dorsally; prementum short and wide, its mid-sagittal

length about 55% of its width ..........Miathyria marcella

15B. Color pattern not as above, head dorsum unpatterned; flagellum

usually banded; abdomen usually concolorous medially along its

length; premental length 65% or more of its width ........16

16A. (15B) Basal halves of pedicel and scape darker than anterior

halves ...........................Pachydiplax longipennis

16B. Pedicel and scape both concolorcus .......................17

17A.(16B) Flagellum 59-64% as long as maximum width of head, tarsi

mostly pale with brown distal tip, palpal teeth occupy nearly

the entire anterior margin (Figure 3F) .....most Tramea

17B. Flagellum less than 56% as long as maximum width of head,

tarsi usually without a darker distal tip, at least the medial

1/3 of the anterior palpal margin without teeth ..........18

18A.(17B) Anterior palpal margin with 2-4 low serrate teeth (Figure 4D),

not common in Florida ................... most Sympetrum

18B. Anterior palpal teeth not so low as to appear serrate, and

often more than 4 teeth present; common species in Florida ...19

19A.(18B) Tip and base of tarsus darker than middle portion, dorsal

head surface without longitudinal lines of fine points, 2 or 3

of the palpal teeth pointed ........Erythrodiplax minuscule

19B. Tarsus concolorous, gray; dorsal head surface with or without

longitudinal lines of fine points, 2-5 of the palpal teeth

pointed .................................................. 20

20A.(19B) Distal ends of tibiae not pale, posterior head setae

about 1.5X the thickness of the adjacent more anterior setae,

dorsal surface of head without longitudinal lines of fine

points ..............................Ladona deplanata

20B. Distal ends of tibiae pale, posterior head setae less than

1.5X the thickness of the adjacent more anterior setae, dorsal

surface of head with longitudinal lines of fine points .......


21A. (14B) Tip and base of flagella dark ....................... 22

21B. Flagella unhanded ...................................... 25

22A.(21A) Flagella 59-64% as long as maximum width of head;

tarsi mostly pale with brown distal tip ...... Tramea in part

22B. Flagella less than 56% as long as maximum width of head;

tarsi without dark distal tip ............................ 23

23A.(22B) Dorsum of head marked with brown, a mid-dorsal, longi-

tudinal, club-shaped mark on occiput; posterior pair of head

setae about 1.5X as thick as the adjacent anterior pair;

tibia with both proximal dark hand and gray band at 2/3 of

its length; anterior palpal margin toothed nearly to medial

margin (Figure 5C) ......................... Plathemis lydia

23B. Dorsum of head without distinct markings; head setae of about

the same thickness; tibiae with only proximal dark band, or

unbanded; more than half of anterior palpal margin without

teeth ................................................... 24

24A.(23B) Anterior palpal margin with 4 pointed teeth plus 2-3

square-ended teeth (Figure 5D); tibiae with dark proximal

band ................................... Orthemis ferruginea

24B. Anterior palpal margin with 2-4 low, pointed,-serrate teeth

(Figure 4D), no square-ended teeth; tibiae unbanded ...........

Sympetrum in part

25A.(21B) Femur with a dark band at 2/3 of its length; foregut

and midgut pigmented with dark granules; flagellum with long,

transparent, acuminate tip about 20% of the length of the

flagellum ................................... Dythemis velox

25B. Femur unbanded; foregut and midgut not pigmented with dark

granules; transparent flagellum tip, if present, less than

15% of the length of the flagellum ....................... 26

26A.(25B) Labium corduliid -- anterior palpal margin with 7-8

pointed teeth, antero-medial corner crenate, bifid ligular

projection present (Figure 3D) ................. Somatochlora

26B. Labium libellulid -- anterior palpal margin with 2-4 of the

teeth pointed; antero-medial corner may be slightly crenate;

ligular teeth may be present, but are not formed into a bifid

projection (Figures 4D,5H) ................................ 27


27A. (26B) Anterior palpal margin with 2-4 tall, pointed teeth plus

4-5 rounded teeth (Figure 5H) ....................... Pantala

27B. Anterior palpal margin with 2-4 low, pointed teeth laterally,

the rest of the margin smooth or slightly crenulated

(Figure 4D) ................................ Sympetrum in part



0.25 mm




Figure 2. Prementum and palps of second larval instars of 5 families
of Anisoptera, seen in dorsal view at 200X. A. Petaluridae,
B. Cordulegastridae, C. Aeshnidae, D. Comphidae, E. Macromiidae.







Figure 3. Left palp and anterior premental margin of Corduliidae
and Libellulidae second instars in dorsal view at 430X.
A-D Corduliidae, E-F Libellulidae.





01 \




Figure 4. Left palp of Libellulidae second instars in dorsal
view at 430X.










Figure 5. Left palp of Libellulidae second instars in dorsal
view at 430X.











Figure 6. Spines and setae of anisopteran second instars.
A and B at 100X, C-J at 430X. A. Left lateral view of
ventral thoracic and abdominal spines, B. Left lateral
view of dorsal abdominal spines, C. Ventral view of distal
hind tibia showing digging setae, D. Ventral view of
distal fore tibia showing tibial comb, E. Claws and distal
end of fore tarsus, F-H. Horns as seen flattened by a
cover slip, I. Occipital seta, J. Dorsal view of left
paraproct showing bottle-brush setae.





Figure 7. Heads of anisopteran second instars in dorsal view.
A. at 100X, B-D. at 200X.

Diagnostic Descriptions

The descriptions in this section are not intended to be complete

in every detail, but to supplement and confirm identifications made

with the keys. Where possible, growth changes for the third and fourth

instars are given so that the reader can separate those instars from

the second instar, and as a step toward identifying all the instars of

Florida Anisoptera. More instars are described for Macromiidae and

Cordulegastridae because no life histories in these families have been

published previously. Some growth changes are listed in Table 3 for

ready comparison among species. The ommatidia of all species in

life are dark red-brown to black. I did not note any differences

more than individual variation between specimens from different broods,

regardless of geographic origin.

Petaluridae. The only petalurid species in eastern North

America is described below. It is a generally scarce and local insect

whose habitat is hillside spring seepages in deciduous forest. No

tibial or tarsal combs are present, and the palps lie in the plane of

the prementum.

Tachopteryx thoreyi

Diagnosis: The general appearance is distinctive, due to the combination

of large size, uniformly brown coloration, stout antennae, and

stout legs. T. thoreyi has several features unique among the

Anisoptera of Florida, including the ligula with an open cleft,

the stout spine at the base of the movable hook, and the 4 stout

setae at the distal end of the tibia.

Size: Total length 2.24-2.38 mm, head width 0.48-0.51 mm.

Color: Entirely pale brown in life; head, thorax, and abdominal

segments 1-2 a little darker.

Head: About 2X as wide as long. Antennae stout, pedicel about as

wide as long, ratio of segment lengths about 2:3:7.

Labium: Palps with 7-11 sharp teeth, the row extending well onto the

medial border; a short, stout, spine at the base of the movable

hook; ligula with an open V-shaped cleft flanked by a large

triangular tooth and 2 short setae on each side (Figure 2A).

Thorax: Legs stout, 4 large digging setae at the distal end of

each tibia (Figure 6C).

Abdomen: Many long hair-setae, no dorsal or lateral spines.

Growth Changes:

Instar 3: Total length 2.50 mm, head width 0.72 mm, tarsi

2-segmented, 6-7 equal ligular teeth, 11-13 palpal teeth.

Instar 4: Total length 3.30 mm head width 0.88 mm, antennae

4-5 segmented, tarsi 2-segmented, 9 ligular teeth,

17 palpal teeth, small lateral spine on abdominal

segment 9.

Remarks: Wilson (1917) found that the second instars of the Zygoptera

Enallagma hageni (Walsh) and E. signatum (Hagen) had a spur at

the base of the movable hook as in T. thoreyi. Possibly these

spurs are homologous with che major palpal setae of other families

of Anisoptera and Zygoptera.

Aeshnidae. Larvae of this family have a characteristic

appearance in all instars, given by the large eyes, elongate subcylindri-

cal abdomen, prominent color pattern, and general paucity of setae. A

characteristic of aeshnids not found in other second instar larvae is

the tarsal comb, composed of mixed branched and serrated setae on the

ventral side of the tarsi. The tibial combs each consist of several

branched setae, more than in other families. The labium (Figure 2C)

has the palps truncate and lying in the same plane as the prementum.

The palps have small teeth all along the anterior border. Near the

base of the movable hook is a short but stout seta which is in the

position of the major palpal setae of the Cordulegastridae, Macromiidae,

Corduliidae, and Libellulidae. As Corbet (1955,p 194) said, "It is

tempting to regard this as representing the homologue of the primary

palpal seta . of the . Libellulidae." The ligula is cleft,

but the cleft is closed, except in some cases for a minute anterior notch.

All species examined had lateral abdominal spines on 7-9 except for

Gomphaeschna furcillata which had lateral spines on 9 only. G. furcillata

is also unique in having small eyes for an aeshnid, evidently compensated

for by its exceptionally long antennae. All species examined lack

dorsal abdominal spines in the second instar. Long tip setae are present

on the paraprocts (except in Coryphaeschna) but there is no tip seta

on the epiproct.

Genera Not Examined:

Basiaeschna janata

Boyeria vinosa

Gynacantha nervosa

Triacanthagyna trifida


Species Not Examined:

G. antilope (Hagen)-known habitats Sphagnum-Taxodium swamps

Gomphaeschna furcillata

Diagnosis: The general appearance is distinctive among aeshnids due

to the long antennae, small eyes, color pattern, and lateral

abdominal spines present only on 9.

Size: Total length 2.44 mm, head width 0.44 mm.

Color Pattern: Generally pale brown, distal half of flagellum pale,

top of head with a large pentagonal pale spot, legs pale with

dark band at 3/4 the length of the femur, abdomen darkens

posteriorly to 9 but 10 and epiproct pale, paraprocts with wide

median brown band.

Head: Eyes small for an aeshnid, occupying the anterior 1/3 of the

lateral head margin; antennae as long as head, flagellum bulging

distally beyond a slight constriction. Four pairs of setae

dorsally, each pair thicker than the adjacent anterior pair;

2 eyelash setae.

Labium: A notched tooth and 2 short setae on each side of the ligular

cleft, the latter slightly open anteriorly; palps with 9-11

anterior teeth, medial margin slightly serrate; minor premental

setae 6-8 present.

Abdomen: Lateral spine only on 9.

Remarks: This species was reared to instar 4 from eggs obtained by

Kennedy (1936). He described dark lateral spots on abdominal

segments 3-7, and 2 bristles on each eye. The latter are

actually above the eye, but appear at certain microscope focus

planes to grow from the eye.

Growth Changes from Kennedy (1936), and original data:

Instar 3: Total length 2.5 mm; antennae 4-segmented; 4-6

ligular teeth, each with a seta lateral to it; lateral

spines on abdominal segments 8-9.

Instar 4: Total length 3.0 mm; antennal segment 4 with black

tip and base, segment 3 with black base, curved black

spot medial to each eye; 5-6 ligular teeth. Tarsi 1-

or 2-segmented and lateral abdominal spines on 8 and 9,

6-7 ligular teeth.

Nasiaeschna pentacantha

Diagnosis: Easily distinguished from other Florida aeshnids by the

2 pairs of horns on the head (Figure 7A).

Size: Total length 2.56 mm, head width 0.76 mm.

Color Pattern: Mostly dark brown, antennae pale except for dark tip

and base of flagellum, anterior half of head pale, abdominal

segments 1-4 mostly pale, the pale areas of head and abdomen

connected by a narrow pale mid-dorsal line on the thorax,

femora pale with dark bands at 1/4 and 3/4 of their length,

abdominal appendages pale.

Head: Rear corners with anteriorly curved horns which extend laterally

beyond the level of the eyes, anterior vertex with a second

pair of anteriorly slanted shorter horns.

Labium: Ligula with 4-5 pointed teeth and 2 short setae; palps with

9-10 pointed anterior teeth, medial margin serrate.

Abdomen: Minute lateral spine on 6, large divergent lateral spines

on 7-9; no dorsal spines.

Growth Changes:

Instar 3: Mid-dorsal spines on abdominal segments 7-9. These

remain to the last instar and are unique among Nearctic

aeshnids. Tarsi 2-segmented, large lateral spines on

abdominal segments 6-9.

Instar 4: Antennae 4-segmented, tarsi 2-segmented.

Remarks: Munchberg (1930) showed the European Brachytron pratense

with similar but straighter lateral horns on the head, but

B. pratense lacks vertex horns.

Epiaeschna heros

Diagnosis: Quickly recognized by color pattern and the 1 pair of short

horns on the rear corners of the head.

Size: Total length 2.72 mm, head width 0.80 mm.

Color Pattern: In life mostly black; flagellum with white band

around middle; anteclypeus with variable pale spots; posterior

half of head dorsum with a large crescent-shaped pale mark;

labium gray, femora transparent with dark bands at 1/4 and 3/4

of their length; tibiae pale with dark proximal, central, and

distal bands; tarsi and claws gray; abdominal segemnts 1-4, 10,

and epiproct white; antero-lateral corners of abdominal

segments 6-9 white; base and tip of paraprocts black.

Head: Each rear corner with a conical projection whose length equals

its basal width.

Labium: Ligula with 3-5 pointed teeth and 1 short seta; 10-13 pointed

palpal teeth (Figure 2C).

Abdomen: Short lateral spines on 7-9.

Growth Changes:

Instar 3: Tarsi 2-segmented; 13-14 palpal teeth; 9 ligular

teeth, the sixth from the slightly open cleft the largest.

Instar 4: Tarsi 2-segmented; antennae 4-segmented; lateral

spines on abdominal segments 6-9; 13-15 palpal teeth;

10-11 ligular teeth, the sixth the largest.


Species Not Examined:

C. viriditas Calvert -- south Florida

Coryphaeschna ingens

Diagnosis: Easily recognized by the color pattern, particularly by

the red mid-dorsal stripe on the thorax. The form of the

antennae and the ridged frons are also distinctive.

Size: Total length 2.92 mm, head width 0.88 mm.

Color Pattern: Mostly brown, antennae pale, pale median spot on

anterior frons, pair of small pale spots on front of bulge of

frons, pale crescent-shaped mark on head dorsum extends from

eye to eye, pale mid-dorsal stripe extends from pale area of

head to epiproct, this stripe wide on thorax and abdominal

segments 1-4 and.7, but obscure on abdominal segments 5-6 and

8-10. A red mid-dorsal stripe within the pale stripe on thorax

and abdominal segments 1-3. Epiproct brown, paraprocts pale.

Legs pale with dark bands on femora at 1/4 and 3/4 of their

length. Sides of abdominal tergite 7 pale. Palps at base of

movable hook and prementum at base of palps brown, remainder


Labium: Ligula with 4-5 teeth and 2 short setae; 12-13 anterior

palpal teeth, medial palpal margin serrate.

Abdomen: Lateral spines on 7-9; paraprocts pointed, without tip-setae.

Growth Changes:

Instar 3: Tarsi 2-segmented, small lateral abdominal spine

on 6, general body color pale with fine longitudinal

green lines.

Instar 4: Antennae 4-segmented, rear corners of head angulate,

suggesting the shelf-like occiput of later instars.

Remarks: This was the only species examined with a red marking.


The 2 regional species are similar in structure but differ in

color pattern. Anax amazili CBurmeister) probably does not breed

in the United States.

Diagnosis of Anax junius: Color pattern distinctive, pale + mark on

top of head with posterior arm narrow; large mid-dorsal

pale spot on abdominal segment 8.

Diagnosis of Anax longipes: Color pattern distinctive, pale + mark

on top of head, with posterior arm widening posteriorly;

abdomen with yellow-brown bands between the gray segments.

Size: Total length 2.80 mm, head width about 0.80 mm. Calvert (1934)

said the total length of A. junius can he as short as 1.9 mm,

and the head width ranges from 0.70-1.0 mm.

Color Pattern: Major differences between the 2 species are given

above. Both are mostly gray-brown and have a pale spot on

each rear corner of the head. A pale mid-dorsal line on the

thorax continues and widens on abdominal segments 1-2 and

narrows on segment 3. Legs paler than the body, and a pale

epiproct. A. longipes has tergites 2-9 of the abdomen with

anterior and posterior edges yellowish brown, creating narrow

tiger-like bands.

Labium: Ligula with 4-6 teeth and 1 short seta, 12-13 anterior

palpal teeth. A. longipes tends to have the medial palpal

margin crenate, and the ligular setae longer than the ligular


Abdomen: Lateral spines on 7-9 in both species.

Growth Changes of A. junius from Calvert (1934) and Macklin (1963b):

Both authors describedall the instars of this species.

Instar 3: Antennae 4-segmented; tarsi 2-segmented;

segments 1,.2, and 8 of abdomen pale; head width

0.94-1.14 mm.

Instar 4: Like instar 3, but head width 1.00-1.31 mm.

Growth Changes of A. longipes:

Instar 3: Antennae 3- to 4-segmented, tarsi 2-segmented;

total length of exuviae 3.16 mm, head width of

exuviae 1.2 mm; small lateral abdominal spine on

segment 6.

Instar 4: Like instar 3, but total length 4.20 mm, head

width 1.48 mm.

Gomphidae. Larvae of this family are quickly recognized by

their characteristic appearance produced by their short antennae,

small eyes, short legs, lack of color pattern, and usually setose

body. An incipient tiny fourth antennal segment is located at or

near the tip of the flagellum, and the scape lacks the enlarged

medial seta of the other families. Characteristic of gomphids are

the burrowing hooks, which are projections of the postero-distal

part of the fore- and mid-tibiae. The distal ends of the tibiae

have 2 strong setae which are probably the homologues of the tibial

comb setae of other families. Two "bottle-brush" setae are present

on the medial side of each paraproct (Figure 6J), but these are

poorly developed in the subgenus Stylurus. The tip setae of the anal

appendages are small of absent. Some species are the only Anisoptera

known to have dorsal or ventral abdominal spines in the second instar.

The labial palps lie in the same plane as the prementum and have

large pointed teeth anteriorly (Figure 2D). The ligular margin has

several teeth and 1 or 2 short setae on each side.

Genera and Subgenera Not Examined:

Drgoogomphus armatus Selys -- streams

D. spinosus Selys -- streams

Erpetogomphus designatus -- Apalachicola River

Gomphus (Gomphurus) dilatatus Rambur -- streams

G. hybridus Williamson -- Apalachicola River

G. modestus Needham -- Yellow River

Gomphus (Kylogomphus) geminatus Carle -- panhandle streams

Hagenius brevistylus

Diagnosis: Easily distinguished from other gomphids by the 2 pairs

of horns on the head and the oval flagellum.

Size: Total length 1.04-1.30 mm, head width 0.32 mm.

Color: Body gray-yellow, darker hand around central part of femora.

Head: Flagellum oval in dorsal view; a pair of long posterior horns,

each tipped with a slender seta; a second pair of horns as

high as wide behind eyes, each with 3 cylindrical setae on

its summit (Figure 7C).

Labium: Palps with 5 anterior teeth, 1-2 small medial teeth; ligula

with 2 teeth and 1 short seta on each side.

Abdomen: Dorsal spines on 1 or 2-9, no lateral spines.

Aphylla williamsoni

Diagnosis: Readily recognized by the presence of 1 pair of horns on

the head, and dorsal abdominal spines on 3-9.

Size: Total length 1.72 mm, head width 0.32 mm.

Color: Gray.

Head: Lateral edge of flagellum straight in dorsal view, a pair of

horns slant posteriorly without summit setae, head as

long as wide.

Labium: Palps with 5 fang-like distal teeth, 4 medial teeth; ligula

with 6-7 teeth, approximately the fourth from the midline

the longest.

Abdomen: High, slender, dorsal spines on 3-9 (Figure ;6B); 10 nearly

2X as long as anal appendages.

Growth Changes: In a specimen 9 mm long, the dorsal spines on 3-9

are proportionately low, but dorsal spines have developed

on 1 and 2 which remain to the final instar. The 9 mm

larva has segment 10 already tubelike, and as long as

segments 5-9 of the abdomen. Bick and Aycock (1950) and

Hornuff (1950) have described some growth changes in this

species from the eighth or ninth instar, which is 15 mm

long, to the last instar.


Species Not Examined:

P. alachuensis Byers -- Florida peninsula

P. bellei Knopf and Tennessen -- Florida panhandle

Progomphus obscurus

Diagnosis: Quickly distinguished by its paucity of setae, and dorsal

spines on abdominal segments 8 and 9.

Size: Total length 1.48 mm, head width 0.34 mm.

Color: Transparent in life, uniformly brown in alcohol.

Antennae: Flagellum with straight lateral edge in dorsal view, about

35% as long as head width.

Labium: Palps with 5-6 anterior teeth, 1-2 small medial teeth;

prementum narrows anteriorly, widest at half its length;

minor premental seta 9 points straight anteriorly; ligula

slightly notched, with 4-6 teeth on each side.

Thorax: Protarsi short, about 35% as long as the head width.

Abdomen: Dorsal spines present on segments 8 and 9; nearly without


Growth Changes:

Instar 3: Antennae with rudimentary fourth segment at

the distal tip of the flagellum; total length 1.76 mm,

head width 0.40 mm; rudiments of dorsal spines on

abdominal segments 4-9.

Instar 4: Antennae 4-segmented, the fourth segment 1/5

as long as the third; total length 1.64 mm in life,

head width 0.44 mm; rudiments of dorsal spines on

abdominal segments 1-9, no lateral abdominal spines;

labrum with anterior medial bump; tarsi still


Remarks: The thick cuticle, smooth body surface, and narrowed

prementum seem to be adaptations for sand burrowing.

Arigomphus pallidus

Diagnosis: The ventral thoracic and abdominal spines (Figure 2A),

and the bulbous setae tipping the horns (Figure 6F) are


Size: Total length 1.60 mm, head width 0.34 mm.

Color: Transparent in life.

Head: Occiput with a pair of posteriorly slanting horns which also

spread laterally, each horn tipped with a dark seta

that is inflated proximally. Two setae are placed near

the base of the antennae, and 2 more setae are placed

medial to each horn.

Labium: Anterior palpal margin with 6 teeth, medial margin with

1-2 teeth; 5-7 ligular teeth (Figure 2D); minor

premental seta 9 sometimes resembles a bottle-brush,

like the setae on the paraprocts.

Abdomen: Unique mid-ventral spines on segments 2-8, each flanked by

a seta on both sides. Lateral spines on 5-9, prominent

on 6-9; a pair of dark, thick, dorsal setae mounted on

tubercles on 1-9; segment 10 as long as wide.

Thorax: Unique mid-ventral spines on meso- and metathorax.

Growth Changes:

Instar 3: Head width 0.44 mm; total length 1.92 mm; antennae

with tiny terminal fourth segment; setae on horns clavate,

bulbous distally; palps with 5 anterior teeth and 3 medial

teeth; ligula with 8-9 teeth on each side; prothorax with

a dorsal pair of bulbous setae; lateral spines only on

abdominal segments 7-9.

Instar 4: Read width 0.50-0.54 mm, total length 2.64-2.68 mm,

12 ligular teeth, small dorsal spine on abdominal segment 9,

tarsi 1-segmented and ventral spines still present on thorax

and abdomen. Larvae 10 mm long lack horns and ventral spines.

Gomphus (Gomphus)

Species Not Examined:

G. hodgesi

G. descriptus

The species in this subgenus are much alike. The key

presented earlier must be considered somewhat tentative. This subgenus

can be differentiated from other Floridae Gomphidae in that horns,

dorsal abdominal spines, and specialized abdominal setae are all

lacking, but well developed bottle brush setae are present on the

paraprocts. The second instars are transparent in life. Abdominal

segment 10 is developed to some extent as a respiratory siphon, 48%

or more as long as wide. Tiny abdominal spines are present on the

posterior abdominal segments, hut it is often a subjective judgement

as to whether a particular segment does or does not have a spine.

G. australis, G. cavillaris, and G. diminutus have the seta at the

rear corner of the head thickened. This seta is exceptionally robust

and mounted on a tubercle in G. australis. Two pairs of dorso-lateral

setae are present on abdominal segments 2 to 9. The epiproct has 2

pairs of robust lateral setae. Knopf (1977) has synonymized G. brimleyi

Muttkowski with G. cavillaris on the basis of identical electrophoretic

patterns of 22 proteins.

Growth Changes of G. minutus:

Instar 3: Total length 1.76 mm, head width 0.42 mm, rudimentary

fourth segment at distal end of antenna, lateral spines

on abdominal segments 6-9, palps with 5-7 anterior teeth

and 2-3 medial teeth, 8-9 ligular teeth of uneven length,

3 bottle-brush setae on each lateral margin of epiproct.

Instar 4: Total length 1.86 mm, head width 0.46 mm, antennae

4-segmented, lateral spines on abdominal segments 5-9,

palps with 6 anterior teeth and 4 medial teeth, 11 ligular

teeth, 4-5 bottle-brush setae on each lateral margin of

epiproct, tarsi still 1-segmented.

Gomphus (Stylurus)

Of the 3 species of this subgenus examined, G. laurae and

G. plagiatus are much alike, but G. townesi is so different as to

seem to belong to another genus. All 3 species, however, have the

following characters in common: Head as wide or wider behind the eyes

as across the eyes, no tubercles on head, no abdominal spines

dorsally, no setae on the epiproct, and reduced development of the

bottle-brush setae on the paraprocts. The claws of last larval instars

of all 3 species are hairy, but only G. townesi of the anisopteran

second instars examined had hairy claws.

Species Not Examined:

G. ivae

G. potulentus

Gomphus (Stylurus) laurae

Diagnosis: A pair of stubby dorsal setae on each of abdominal segments

2-8, each of the stub-setae flanked on both sides by hair-setae.

Size: Total length 1.46 mm, head width 0.34 mm.

Color: Gray.

Labium: Palps with 5-6 teeth anteriorly, 2-3 small medial teeth;

7-9 ligular teeth of even length but uneven thickness.

Thorax: Two pairs of dorso-lateral setae on prothorax, usually 1 pair

on meso- and metathorax. Protarsi and mesotarsi short, length

of protarsus 33% of head width.

Abdomen: A pair of stout, stubby, dorso-lateral setae on each of 2-9;

becoming flattened and scale-like on 8-9; the stub-setae flanked by

hair-setae medially and laterally on 2-8, laterally only on 9;

lateral spines on 4-9, minute on 4-6, large and flat on 7-9.

Comphus (Stylurus) plagiatus

Diagnosis: Like G. laurae, hut stub-setae not flanked medially by


Size: Total length 1.06-1.26 mm, head width 0.30-0.32 mm.

Color: Gray.

Labium: Palps with 5-6 anterior teeth, 1-4 small medial teeth;

5-6 ligular teeth.

Thorax: Length of protarsus 32% of head width.

Abdomen: Stout, stubby, dorso-lateral setae on 2-9, flanked by

hair-setae laterally but not medially; lateral spines on 5-9,

large and flat on 7-9.

Gomphus (Stylurus) townesi

Diagnosis: Pairs of spike-setae on rear corners of head and every

body segment except the prothorax, claws hairy (Figure 6E).

Size: Total length 1.56 mm, head width 0.34 mm.

Color: Gray.

Head: A stout spike-like seta at each rear corner.

Labium: Palps with 4-7 anterior teeth and 2-5 small medial teeth;

7-9 ligular teeth.

Thorax: Prothorax with 2 pairs of hair-setae dorsally; meso- and

metathorax with a pair of dorsal, medial, thick, dark, spike-

setae mounted on tall cone-shaped tubercles, each of the these

flanked by a hair-seta laterally. Leg setae and claws are

themselves finely hairy at 430X; protarsus 32% of head width;

burrowing hooks prominent.

Abdomen: Pairs of dorsal, stout, dark, spike-setae mounted on tubercles

on segments 1-9, similar but shorter setae not mounted on

tubercles on 10; spike-setae flanked by medial hair-setae on 1-8

and by lateral hair-setae on 1-9; lateral spines on 4-9, large

and divergent on 6-9.

Cordulegastridae. Only the genus Cordulegaster is found in

North America. All of the species live in unpolluted spring seepages

or streams. Judging from the single species available for examination,

the second instars are in a less advanced growth stage than second

instars of the remaining families, in that the second instar of C. sayi

lacks major palpal setae and tibial combs. Both of these types of

setae develop in the third instar.

Species Not Examined:

C. fasciata Rambur

C. maculata Selys

Cordulegaster sayi

Diagnosis: The widely cleft projecting ligula is distinctive (Figure 2B).

Size: Total length 1.68 mm, head width 0.34-0.36 mm.

Color: Gray-yellow.

Head: Eyes directed as much anteriorly as laterally; flagellum long,

3-4X length of pedicel (Figure 7B).

Labium: Entire ligula projecting anteriorly, the projection widely

V-cleft in the midline; 4-5 sharp, separated, anterior palpal

teeth of about equal length; no major palpal setae; movable

hook short and blunted.

Thorax: No tibial combs, claws long and slender.

Abdomen: Numerous hair-setae, no dorsal or lateral spines.

Growth Changes:

Instar 3: Total length 2.30 mm, head width 0.44-0.48 mm;

1 major palpal seta, 1 major premental seta; anterior


palpal teeth large and interdigitating; tarsi 2-segmented;

3-5 stout spine-like setae on distal ends of tibiae, some

of these branched; a pair of thick blunt setae dorsally on

each thoracic segment and abdominal segments 4 and 5.

Instar 4: Two major palpal setae, 3 major premental setae, antennae

5-segmented, 3 blunt setae on dorsal surface of epiproct.

Instar 5: Four major premental setae, lateral abdominal spine on 9.

Instar 6: Three major palpal setae, 6 major premental setae.

Instar 7: Major premental setae 6-7, antennae 6-segmented,

lateral abdominal spines on 8 and 9, protarsus 2-segmented,

meso- and metatarsus 3-segmented, pairs of blunt setae on

each segment of thorax and abdominal segments 1-5.

Total length 5.44 mm, head width 1.05 mm.

Remarks: The blunt setae on the dorsum of thorax and abdomen look as

if they could be depth sensors, informing the larva how deep

it is buried in silt.

Macromiidae. The single species available for examination has

a labium resembling that of the Corduliidae with the antero-medial

corner of the palp crenate, and sometimes a bifid ligular projection

(Figure 2E). The rostral horn so characteristic of the later instars

is not present in any of the first 6 instars. The tibial combs are

like those of the Corduliidae and Libellulidae, with 2 branched setae

at the distal end of each tibia on the underside. The general appearance

of the larva in late instars is distinctive with its long, gangling, legs,

but in the second instar all the larvae of the Corduliidae and Libellulidae

resemble Macromiidae because they too have relatively long legs.

No dorsal or lateral abdominal spines are present.

Genus Not Examined:

Didymops floridensis Davis--sand-bottomed lakes

D. transversa (Say)


Species Not Examined:

M. alleghaniensis Williamson--panhandle streams

M. georgina (Selys)

Macromia taeniolata

Diagnosis: The scale-like seta on the summit of each horn is unique

(Figure 6G).

Size: Total length 1.28 mm, head width 0.30-0.34 mm.

Color: Gray-yellow.

Head: No rostral horn; a pair of tall, thick, horns on vertex, each

tipped with a flat, scale-like seta; 3 setae are present anterior

to each horn, the most posterior of these on the base of the horn.

Labium: Palps with 5-7 anterior teeth, the lateral 2-5 pointed;

antero-medial corner of palp crenulate; ligula with a low

triangular tooth and a short seta on each side, sometimes a

bifid ligular projection. One major palpal seta present(Figure 2E).

Thorax: A short, robust seta on the side of the thorax above the base

of each leg, claws long and slender.

Abdomen: Paraproct and epiproct tip-setae short and blunt, that of

paraproct 15% of paraproct length excluding the seta.

Growth Changes:

Instar 3: No seta at tip of horn, 1 major premental seta,

dagger-setae on several palpal teeth.

Instar 4: Two major palpal setae, 3 major premental setae.

Instar 5: Three major palpal setae, 4 major premental setae,

tarsi 2-segmented, antennae 4-segmented.

Instar 6: Three or four major palpal setae, 6 major premental

setae, tarsi 2-segmented, antennae 4-segmented, a black

line connecting the eyes across the frons. Still no

rostral horn, dorsal abdominal spines, or lateral abdominal


Remarks: The only other macromiid second instar that has been described

is the Oriental Epophthalmia vittata (Lieftinck,1931). This

species has several unique features: 2-branched horns, cupped

setae on the thorax, forked setae on abdominal segments 8-10,

and a truncate epiproct with 2 equal setae at the apex. Lieftinck's

Figure 27 represents the antero-medial corner of the palp

as not crenulate.

Corduliidae. The larvae of this family and the Libellulidae are

similar, but in the second instar Corduliidae can be usually differenti-

ated by the presence of a small bifid-notched ligular projection and

a crenate antero-medial palpal border. Representative labia of all

the Florida corduliid genera examined are shown in Figure 3. Some

Libellulidae have small ligular projections, but these are usually

cleft to the base, forming separate teeth. Some species of Libellulidae

have the antero-medial palpal border slightly crenulate (Figures 5C,

5E, and 5E). The differences between these 2 families tend to disappear

in the third and fourth instars because the ligular projection becomes

relatively smaller in the Corduliidae, and the palpal margins become

crenulate in the Libellulidae.

The labial palps are cupped dorsally, set in a plane nearly

perpendicular to the prementum. One major palpal seta is present.

The anterior palpal margin is variably toothed, with the largest teeth

near the lateral border and diminishing to creations near the medial

border. The teeth are taller, occupy more of the anterior margin,

and are of more nearly even length than in most Libellulidae. Both

pairs of ligular setae and most or all of the minor labial setae

shown in Figure 1 are present.

The top of the head typically has 4 pairs of setae and in most

genera a pair of horns. On each segment of the thorax are 1 pair of

robust setae dorsally and 1 or 2 small setae laterally. Most segments

of the abdomen have 3 pairs of setae dorsally. Dorsal and lateral

spines are absent. The legs are long and gangling with tibial combs of

2 branched setae on each tibia. Some species have distinctive

color patterns.

Helocordulia selvsii

Diagnosis: Diagnostic are the combination of a pair of short horns, the

corduliid labium, banded femora, and only one dark band on the

antennae, that around the base of the flagellum.

Size: Total length 0.98 mm, head width 0.38 mm.

Color Pattern: Mostly transparent in life with a gray band around

the base of the flagellum, gray bands at 1/4 and 3/4 the length

of the femur, and gray tarsi.

Head: A pair of postero-lateral conical horns, each as high as wide,

and with a tapered seta at the summit. Two setae stand anterior

to each horn.

Labium: Palps with 6 large, pointed, anterior teeth; antero-medial

corner of palps crenate; bifid ligular projection deeply cleft;

dorsal and ventral ligular setae about equal in size (Figure 3A).

Thorax; Each segment with a pair of thick dorso-lateral setae mounted

on tubercles.

Abdomen: Paraprocts sometimes have bottle-brush setae, as in the


Growth Changes:

Instar 3: No ligular projection, 1 major premental seta.

Instar 4: Two major palpal setae, 3 major premental setae,

5-segmented antennae, 2-segmented tarsi; horns twice as

tall as wide, slanting posteriorly, without a summit seta.


Species Not Examined;

S. georgiana Walker--western panhandle

Diagnosis: The combination of the corduliid labium with lack of horns

is diagnostic in Florida.

Size: Total length 1.68-1.88 mm, head width 0.40 mm.

Color: Almost no color pattern. Body gray to pale brown with

rusty-brown rectal gills. In life, S. linearis had dark gray

tarsi, and S. provocans had the thorax and legs paler than

the rest of the body.

Head: No horns present, but see Remarks below. S. filosa has a

pair of low postero-lateral bumps present. Dorsally on the

head are 4 pairs of setae, the postero-lateral pair the thickest.

Labium: Palps with 7-8 anterior teeth, with a minute seta on the most

lateral tooth; antero-medial corner of palps crenate; ligula

with a bifid tooth; ventral ligular setae larger than dorsal

ligular setae (Figure 3D).

Thorax and Abdomen; Setal pattern like that of Tetragoneuria except

that the setae are not on conical bases.

Remarks: Miyakawa (1971) stated that the Japanese S. viridiaenea

Uhler has a pair of tubercles on the occiput, each tipped

with a brush-seta as in Tetragoneuria. In the third instar

a smaller tubercle develops at the base of the seta behind

the eyes, and the brush-seta of the occipital tubercle is

replaced by 4-5 hair-setae. Gardner (1954) also report horns

in second instar S. metallica.

Growth Changes: In S. calverti, S. filosa, and S. provocans, the

ligular projection is not obvious in the third instar and is

no larger than adjacent teeth in the fourth instar. For other

growth changes in these three species, see Table 3. Growth

changes of S. kennedyi are similar (Walker,1925) except that

instar 4 has 5-segmented antennae.


Species Not Examined:

N. alabamensis Hodges -- streams

N. molesta (Walsh) -- Apalachicola River

N. obsoleta (Say) -- bald cypress (Taxodium) rimmed lakes in

north Florida

Diagnosis : The short and robust major palpal seta, shorter than

the movable hook, is unique (Figure 3C). The bottle-brush

setae of the paraprocts are also not found in other regional

larvae, except in the Gomphidae and some Helocordulia. The

color pattern and pair of short horns are as in Helocordulia,

except that the femora are unbanded.

Size: Total length 1.22-1.26 mm, head width 0.32-0.36 mm.

Color Pattern: In life, body nearly transparent with the internal

parts of the head, thorax, and abdomen pale brown. Gray band

at base of flagellum; legs gray with paler proximal trochanter,

joints, and tips of the tarsi; abdomen darker gray along the

lateral edges. Midgut pigmented in alcohol.

Head: A pair of short horns on the occiput about as high as wide,

tipped with a thick seta. Two long setae anterior to horns,

1 short seta posterior to horns. Two eyelash setae above

each eye.

Labium: Major palpal seta thickened for most of its length, shorter

than movable hook. Anterior palpal margin with 6 pointed

teeth, crenate antero-medial corner; bifid ligular projection

present; dorsal ligular setae larger than ventral ligular


Thorax: A pair of long, thick, dark setae on each segment, mounted

on conical bases.

Abdomen: Medial side of each paraproct with 2 bottle-brush setae.

Growth Changes of N. virginiensis:

Instar 3: One major premental seta, 1 major palpal seta a

little longer than movable hook, 3 dagger-setae on

anterior palpal margin, horns without a summit seta.

Instar 4: One major premental seta, 2 major palpal setae,

antennae 5-segmented, tarsi 2-segmented, total length

1.56 mm in life, head width 0.56 mm, horns bright orange.


Species Not Examined:

T. costalis (Selys)

T. spinosa (Hagen) -- Florida panhandle

As expected from adult and last larval instar morphology, second

larval instars of the 3 Florida species examined are nearly identical.

Second larval instars of T. sepia in the one brood available were

dark brown, the other species gray to pale brown.

Diagnosis: The pair of tall horns on the head, tipped with brush-

setae (Figure 6H), combined with the corduliid labium, and 6

anterior palpal teeth, are diagnostic.

Size: Total length about 1.0 mm, head width about 0.36 mm.

Color Pattern: Generally pale brown, T. cynosura in life had the tip

and base of the flagellum gray, basal half of the pedicel gray,

scape gray, distal trochanter gray, femora with gray bands at

1/4 and 3/4 of their length, tibiae gray with pale distal end,

tarsi gray with pale distal end, claws black, antero-lateral

parts of abdominal tergites dark, tips of paraprocts black.

Colors quickly lost in alcohol.

Head: A pair of tall horns on the vertex, each tipped with a thick

seta which usually has the distal end divided and brush-like.

Anterior to each horn are 2 setae, behind each horn on the

occiput is a shorter, thicker seta. The antennae are longer

than the head.

Labium: Labial palps with 6, or occasionally 7, anterior teeth and

a crenate antero-medial corner; ligula with a bifid tooth,

ventral ligular setae much larger than dorsal ligular setae

(Figure 3B). Butler (1904) illustrated a trifid ligular

tooth for T. cynosura.

Thorax: A pair of robust dorso-lateral setae on each segment, set

on conical bases. Lateral to these are 1 small seta on the

prothorax, 2 small setae on the meso- and metathorax.

Abdomen: Segments 5-9 with 5 pairs of setae dorsally, the second

from the midline longest and thickest. The latter are set

on conical bases in T. sepia and T. stella. The longitudinal

tracheae may be pigmented in the base of the abdomen.

Remarks: Kormondy (1955,1959) did not find key differences among

second instar larvae of T. canis, T. cynosura, and T. spinigera.

In his Table 11 (1955), only 1 of 22 characters he measured

did not overlap in size. The shortest epiproct of T. cynosura

was 0.01 mm longer than the longest epiproct of T. spinigera.

Growth Changes of T. cynosura from Kormondy (1955,1959):

Instar 3: One major premental seta, a 2-segmented tarsus in

some specimens.

Instar 4: Antennae 4-5 segmented, tarsi 2-segmented, 2 major

palpal setae, 3 major premental setae. The horns on the

head increased in size to instar 6, remained unchanged

to instar 8, and disappeared by instar 11.

Epicordulia princeps

The second instar of E. princeps, which the author considers

synonymous with E. regina (Hagen), was described by Wilson (1917).

The labium was studied by Butler (1904). The following data are

from these sources.

Diagnosis: Similar to Tetragoneuria, but larger, with 7-8

anterior palpal teeth instead of 6. According to Wilson

(1917) the tips of the horns are hooked posteriorly, but

possibly the "hooks" are thick setae bent over posteriorly

by a cover slip. Wilson also stated that the dark abdominal

markings on the tergites are postero-lateral, rather than


Size: Total length 1.25 mm.

Color: Mostly pale, basal half of flagellum black, basal half of

pedicel black, abdomen with dark spots on the posterior margin

at the lateral edge of each tergite.

Head: A pair of tall occipital horns with the tips hooked posteriorly.

Labium: Palps with 7-8 anterior teeth and a crenate antero-medial

corner. A bifid ligular projection is present.

Remarks: Walker (1966) lumped Tetragoneuria and Epicordulia into

the old world Epitheca. Also, some odonatologists consider

Epicordulia princeps to be a separate species from E. regina.

Both of these problems need more study.

Libellulidae. Most libellulid genera lack horns on the head,

ligular projections, and crenations on the antero-medial palpal

border. Otherwise, Libellulidae are nearly identical to Corduliidae.

See the discussion of the Corduliidae for differences between these

2 families. Representative labia are shown for all the Florida

genera examined in Figures 3, 4, and 5. The ligula of nearly all

the Libellulidae examined looks like Figure 3F.

Genera Not Examined:

Crocothemis servilia

Idiataphe cubensis

Macrodiplax balteata

Tauriphila australis


Both of the Florida species were examined, but no definite

differences could be found between them. Brachymesia furcata occurs

only in south Florida.

Diagnosis: A pair of tall, vertical horns on the vertex, each

usually tipped with a hair-seta. A large, thick seta stands

behind each horn, and the midgut is usually pigmented.

Size: Total length 1.12-1.14 mm, head width 0.30-0.32 mm.

Color Pattern of B. gravida: Mostly transparent in life; tip and

base of flagellum gray, scape and pedicel gray; distal trochanter

gray; femora with gray band at 1/4 and black band at 3/4 of

their length, distal end white; femoro-tibial and tibio-tarsal

joints pale; base of tibiae dark, obscure pale band at 1/4 of

their length, the remainder gray; abdominal tergites with

antero-lateral corners dark, postero-lateral corners white;

paraprocts with white base and dark tip; The color pattern

of the available B. furcata specimens was lost in alcohol.

Head: A pair of tall, vertical horns 0.08 mm long on the vertex,

each with a hair-seta at the summit. The summit seta is

occasionally thickened with a few brush-like divisions, as in

Tetragoneuria. A small seta is located anterior to each horn,

and a large, thick seta posterior to each horn. Flagella about

55% as long as head width.

Labium: Palps with 3 pointed lateral teeth, and 1-3 medial blunt

teeth on the anterior margin; the medial 1/4 of the anterior

margin smooth (Figure 5B). Ligula often with a pair of pointed

teeth between the ventral ligular setae, more often in B. gravida.

Thorax: Each segment with a pair of robust dorso-lateral setae mounted

on small, conical tubercles. Since the eggs of B. furcata are

dark green, and the eggs of B. gravida range from yellow to

green, the midgut is often pigmented with dark yolk granules.

Growth Changes in B. gravida:

Instar 3: One major premental seta, palps with antero-medial

corner crenate, a dagger-like seta at antero-medial

corner of palp.

Instar 4: Two major palpal setae, 1 major premental seta,

antennae 4-segmented, no dorsal or lateral abdominal

spines, 3 dagger-setae on anterior palpal margin, horns

still tall and tipped with a seta, tarsi still 1-segmented.

Nannothemis bella

Diagnosis: Eyes relatively larger than in any other species seen

except species of the Aeshnidae, covering the anterior 1/2 to

2/3 of the lateral head margin (Figure 7D); body dark gray;

Florida panhandle in Sphagnum bogs.

Size: Total length 1.10 mm, head width 0.38-0.40 mm.

Color Pattern: Generally dark gray, distal half of the flagellum

pale, femora with dark bands at 1/4 and 3/4 of their length,

trochanter dark, obscure dark bands at proximal end of tibia

and proximal end of tarsus. Longitudinal tracheal trunks

pigmented full length, from head to hindgut.

Head: Eyes exceptionally large, spanning 1/2-2/3 of the lateral

length of the head; 4 pairs of dorsal setae.

Labium: Distal margin of palps with 4-5 teeth, the lateral 2 or 3

pointed, the medial ones rounded, the medial 2/3 of the distal

margin may be slightly crenulate (Figure 4B).

Thorax: Tarsi relatively short, about 34% as long as head width.

Perithemis tenera

Diagnosis: Immediately distinguished by the pair of tall, vertical

horns on the vertex, with a thick, cylindrical seta standing

behind each horn (Figure 61).

Size: Total length 1.10 mm, head width 0.30 mm.

Color Pattern: In life, generally pale brown; black bands at tip

and base of flagellum; wide pale mid-dorsal stripe on thorax;

dark distal trochanter; dark bands at 1/4 and 3/4 the length

of the femur; tibia dusky, with dark proximal band; tarsi

dusky; lateral edges of tergites white posteriorly, black

anteriorly; paraprocts black-tipped. Specimens become

transparent in alcohol.

Head: A pair of tall vertical horns on vertex, each with a hair-

seta at the tip. Posterior to each horn is a thick, inflated,

cylindrical seta, mounted on a conical base. Anterior to each

horn is a small seta, with another posterior to each inflated


Labium: Anterior palpal margin with 5 teeth, the lateral 2 pointed,

the others truncate or serrate with apices hooked medially;

medial part of anterior margin smooth for a distance of 2

tooth-widths (Figure 5F).

Thorax and Abdomen: A pair of thick, inflated, cylindrical setae

dorsally on each segment from the prothorax to abdominal

segment 9.


No constant differences could be found among the 6 species


Species Not Examined:

C. verna Pritchard -- south to Lake City

Diagnosis: A pair of vertical horns on the vertex 1-2X as high as

their width at the base, each tipped with a hair-seta. There

are 2 hair-setae behind each horn.

Size: Total length about 1.16 mm, head width about 0.34 mm.

Color Pattern: C. ornata in life had the tip and base of the flagellum

dark, delimiting a white band around the middle; distal half

of the pedicel white, basal half black; black band at 3/4 the

length of the femur; white bands at both ends of the femur

and distal end of the tibia; antero-lateral corners of abdominal

tergites black. The only marking on alcohol specimens of all

the 6 species examined was the dark femoral band. Also, the

longitudinal tracheae were pigmented in the thorax and base of

the abdomen.

Head: A pair of vertical horns on the vertex 1-2X as high as basal

width, each horn with a hair-seta at the summit. One seta

stands anteriorly to each horn, 2 setae behind each horn.

Flagellum 62-70% as long as the head width.

Labium: Palps usually with 3-4 teeth laterally on the anterior

margin. C. eponina has 2-3 teeth. The medial half of the

anterior palpal margin is smooth (Figure 4C).

Remarks: C. eponina seems most different from the other species

examined in that it has taller horns, and sometimes only 2

anterior palpal teeth.

Dythemis velox

Diagnosis: Recognized by the combination of a dark band at 2/3

the length of the femur, darkly pigmented foregut and midgut,

and long transparent tip on the flagellum. Not found in the

Florida peninsula.

Size: Total length 1.14 mm, head width 0.34 mm.

Color: Gray with a pigmented foregut and midgut, although the yolk

is the usual pale yellow; faint brown bands at 2/3 the length

of the femora.

Head: Flagellum with a clear acuminate tip 20% of flagellum length,

flagellum 54% as long as head width; 3 or 4 pairs of setae

on vertex.

Labium: Anterior palpal margin with 3 or 4 pointed teeth laterally,

1 blunt tooth medially, medial 1/3 of the anterior margin

smooth (Figure 3E).


Species Not Examined:

E. plebeja (Burmeister)--south Florida

Erythemis simplicicollis

Diagnosis: E. simplicicollis has a distinctive color pattern. Body

dark brown with a nearly full length pale mid-dorsal stripe

from the labrum to segment 9 of the abdomen. The pale stripe

is widened to 1/4 the width of the head on the occiput. Palps

with only 1 or 2, occasionally 3, pointed anterior teeth.

Size: Total length 1.18 mm, head width 0.36 mm.

Color Pattern: In life dark brown with a cream-colored mid-dorsal

stripe from labrum to abdominal segment 9, the stripe widened

to about 1/4 the head width in a violin-shaped marking on the

occiput. Femur pale with brown distal band, tibia pale with

brown proximal band, the femoro-tibial joint pale. Tarsi and

claws brown. Sides of thorax above coxae with small pale spots,

and epiproct pale. In alcohol the legs become brown with

pale joints.

Head: Vertex with 3 or 4 pairs of setae; eyes directed laterally

and dorsally, not anteriorly.

Labium: Anterior palpal margin with 1-3 low pointed teeth laterally,

with a few medial creations; most of anterior border nearly smooth

(Figure 4A).

Abdomen: Seta at tip of paraproct short, about 20% of paraproct

length excluding the seta.

Growth Changes from Bick (1941), who described all the instars:

Instar 3: One major premental seta, anterior palpal margin

with 3 dagger-like setae.

Instar 4: Three major premental setae, 2 major palpal setae,

anterior palpal margin with 6 dagger-setae, antennae

4-segmented, tarsi still 1-segmented.

Remarks: The western Nearctic E. collocata has a pale mid-dorsal

line which extends posteriorly only to abdominal segment 3,

but the labium is like that of E. simplicicollis. The labium

of both species is different from that of Lepthemis vesiculosa,

which some odonatologists consider congeneric with Erythemis.

The figure of E. simplicicollis in Needham and Heywood(1929)

is apparently some other species, since prominent horns on the

vertex are shown.

Wilson (1917) and Bick (1941) have both described the second

instar of E. simplicicollis. Bick questioned the existence of

the minor labial setae figured by Wilson, and thought that Wilson

indicated a cleft prementum in his figure. My specimens have the

minor palpal and premental setae as shown by Wilson. Probably

Wilson did not intend to show a cleft prementum, but rather folds

or lines to demonstrate that the prementum is slightly cupped.

Lepthemis vesiculosa

Diagnosis: In Florida, restricted to the southern peninsula. Morpholog-

ically like Erythemis simplicicollis, as in the short paraproct

tip-setae, but with 3-5 large pointed teeth on the anterior palpal

margin instead of 1-3 small pointed teeth (Figure 4F). Color

pattern unknown, probably similar to that of E. simplicicollis.

Size: Total length 1.30, head width 0.42 mm.

Color Pattern: Specimens in alcohol are pale brown with an obscure

pale mid-dorsal line on the thorax.

Head: Dorsal surface with 4 pairs of setae.

Labium; Anterior palpal margin with 3-5 pointed teeth laterally,

followed by 1 or 2 blunt teeth medially, then low crenations

to a smooth antero-medial margin.

Abdomen: Setae at tips of paraprocts short and stout, about 17%

as long as the paraprocts excluding the setae.


Species Not Examined:

E. umbrata (Linnaeus) -- south Florida

Diagnosis for E. berenice: The color pattern is distinctive, and

the habitat is salt marsh. Body brown with a large, pale,

wedge-shaped mark on the top of the head; tip and base of the

flagellum dark; color pattern superficially like Erythemis


Diagnosis for E. minuscule: Color pattern markedly different from

E. berenice. Color pattern similar to that of Libellula, except

that the tip and base of the tarsi are darker than the central


Size: Total length 1.14-1.18 mm, head width 0.32-0.38 mm.

Color Pattern of E. berenice: Body brown with the following areas

pale: a large wedge-shaped mark on the head dorsum, spreading

posteriorly from a point on the frons; zones at the bases of

the compound eyes; femoro-tibial joint; tibio-tarsal joint;

mid-dorsal line on thorax; and segments 9 and 10 of the abdomen.

The tip and base of the flagellum are dark.

Color Pattern of E. minuscule: Mostly translucent in life; tip and

base of the flagellum black; distal trochanter gray; femora

with gray band at 1/4 and black band at 3/4 of their length,

distal end white; tibiae with black proximal band and obscure

pale band at 1/4 of their length; tarsi gray with base and

tip darker; lateral edges of abdomen darker, postero-lateral

corners of tergites white.

Head: Four pairs of setae on dorsum, these setae thin in E. berenice,

thick and robust in E. minuscule. Flagellum of the antennae

long, 52-56% as long as head width. Surface of head covered

with curved lines of fine dark points in E. berenice, apparently

not so in E. minuscule.

Labium: Anterior palpal margin with 4 teeth, the most lateral 2 or 3

pointed, the others rounded; medial half of the distal margin

smooth. The pointed teeth are larger in E. berenice (Figure 4E).

Abdomen: Paraproct tip-seta exceptionally long and thin in

E. berenice, about 44% of paraproct length, compared with

about 33% in E. minuscule.

Remarks: Some odonatologists consider E. minuscule to be a subspecies

of E. connata. No difference was noted between second instars

of these two species or subspecies. The other species differ-

ences observed in this genus are relatively great for libellulids.


L. pulchella was not examined in this study, but was described

by Wilson (1917). No differences among the 8 Florida species were

found on which to base a key.

Diagnosis: Color pattern like that of Ladona deplanata, Erythrodiplax

minuscule, Pachydiplax longipennis, Perithemis tenera, and

Tetragoneuria, but distinguished by the combination of pale

distal ends on the tibiae, lines of fine points on the surface

of the top of the head, pale unbanded scape and pedicel, and

lack of horns.

Size: Total length about 1.0 mm, head width 0.32-0.38 mm.

Color Pattern: In life, body mostly pale yellow-brown, with the

following dark gray or black: tips and bases of flagella;

proximal trochanter; bands at 1/4 and 3/4 the length of the

femora; the tarsi, claws, anal valves, and the tips of

paraprocts. Tibiae gray with pale distal ends and band at

1/4 of their length, the proximal end darker. Abdominal ter-

gites with black antero-lateral corners, and white postero-

lateral corners. The coxae and both ends of the femur are


Head: Dorsum with 4 pairs of setae, these becoming a little thicker

posteriorly; dorsal surface with longitudinal lines of minute


Labium: Anterior palpal margin with 3, sometimes 4-5 pointed teeth

laterally, and 1, sometimes 2, rounded teeth medially; medial

1/3-1/2 of anterior margin smooth (Figure 5E).

Abdomen: Terminal seta of paraprocts 2X as long as the terminal

seta of the epiproct. Epiproct with 1 or 2 robust lateral

setae on each side. Longitudinal tracheal trunks pigmented

in basal part of abdomen.

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