• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Table of Contents
 Introduction and literature...
 Methods and materials
 Descriptions of adult and...
 Eggs and larvae
 Conclusions
 Literature cited
 Historic note






Group Title: Bulletin - Agricultural Experiment Stations, University of Florida ; 816 (technical)
Title: Morphological studies on the beet armyworm Spodoptera exigua (Hubner) (Lepidoptera Noctuidae)
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027449/00001
 Material Information
Title: Morphological studies on the beet armyworm Spodoptera exigua (Hubner) (Lepidoptera Noctuidae)
Series Title: Bulletin Agricultural Experiment Stations, University of Florida
Alternate Title: Spodoptera exigua
Physical Description: 37, 1 p. : ill. ; 23 cm.
Language: English
Publisher: Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla.
Publication Date: 1980
 Subjects
Subject: Beet army-worms
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 35-38
Statement of Responsibility: Ngo Dong ... et al..
 Record Information
Bibliographic ID: UF00027449
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000404666
oclc - 07425914
notis - ACF0881

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page
    Table of Contents
        Table of Contents
    Introduction and literature review
        Page 1
        Page 2
    Methods and materials
        Page 3
    Descriptions of adult and discussion
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
    Eggs and larvae
        Page 32
        Page 33
    Conclusions
        Page 34
    Literature cited
        Page 35
        Page 36
        Page 37
        Page 38
    Historic note
        Page 39
Full Text

July 1980


Morphological Studies on

The Beet Armyworm
Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae)



Ngo Dong, T. C. Carlysle, H. L. Cromroy, and D. H. Habeck


Agricultural Experiment Stations
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
F. A. Wood, Dean for Research


Bulletin 816 (technical)








Morphological Studies on
The Beet Armyworm
Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae)

Ngo Dong, T. C. Carlysle, H. L. Cromroy, and D. H. Habeck


; IFA


AUTHORS
Drs. Ngo Dong, H. L. Cromroy, and D. H. Habeck are with the Department
of Entomology and Nematology, Institute of Food and Agricultural Sciences,
University of Florida, Gainesville. T. C. Carlysle is with the USDA, Science
Education and Administration, Agricultural Research Group, at the Insect At-
tractants, Behavior, and Basic Biology Research Laboratory, Gainesville.













CONTENTS

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

LITERATURE REVIEW ....................... ............. 1

METHODS AND MATERIALS ............................... 3

DESCRIPTIONS OF ADULT AND DISCUSSION ................. 3
Antennae ............. ................................ 3
Bohm bristles ................ .. ............... ........ 7
Sensilla chaetica ....................................... 7
Sensilla trichodea .............. ... ...................... 10
Sensilla coeloconica ..................................... 13
Sensilla auricillica ....................................... 13
Sensilla styloconica ...................................... 13
Wings ................ ...................... .............. 16
Dorsal forewing .............. .......................... 17
Ventral forewing ....................................... 17
Dorsal hindwing ....................................... 22
Ventral hindwing ........................................ 23
Scent Glands ..................................... ........ 27
Reproductive Organs .......................... ............. 28
EGGS AND LARVAE ...................................... 32
CONCLUSIONS ......................................... 34

LITERATURE CITED ................ ..................... 35










INTRODUCTION

The beet armyworm, Spodoptera exigua (Hubner), is an important insect
pest which is nearly cosmopolitan in distribution. It was first reported in the
United States from Oregon in 1876 (20) and then spread gradually throughout
the country, reaching Florida in 1924 (50). The polyphagous larvae are eco-
nomic pests on many commercial crops grown in Florida, including tomato,
sweet corn, pepper, peanut, fern, chrysanthemum, and gladiolus.
With the advent of strict environmental hazards laws, knowledge of the basic
biology of insect pests has become increasingly important to the new pest con-
trol strategies. The beet armyworm, although often a serious pest in Florida,
has been little studied, especially in regard to its morphology. This publication
describes some details of the internal and external morphology of the beet ar-
myworm, with special emphasis on details of the reproductive and external
sense organs studied, using both light microscopy and scanning electron mi-
croscopy.


LITERATURE REVIEW

Few detailed studies of the morphology and histology of the beet armyworm
have been done. The morphology of the female sex pheromone glands of the
beet armyworm was described along with seven other noctuid species: Auto-
grapha californica (Speyer), Pseudoplusia includes (Walker), Rachiplusia ou
(Guenee), Feltia subterranea (Fabricius), Heliothis zea (Boddie), Heliothis
phloxiphagus (Grote), and Heliothis virescens (Fabricius) (24, 25). The loca-
tion of the glands of each species was described and some comparisons were
presented. Hammad (18) described scent glands of different noctuid species:
Agrotis ipsilon (Hufnagel), Syngrapha circumflexa (Linnaeus), Earias insu-
lana (Boisduval), Leucania loreyi (Duponchel), Ostrinia nubilalis (Hubner),
Chilo simplex (Butler), Platyedra gossypiella (Saunders), and S. exigua. He
reported that the S. exigua scent glands were of the brush-like type and were
found in the eighth abdominal segment.
The external morphology of the antennae of four noctuid species--Tricho-
plusia ni (Hubner), Heliothis zea, S. ornithogalli (Guenee), and S. exigua-
was described, and different types of sensillae were classified, although varia-
tions among the species were slight (26).
These are the only known morphological studies of the beet armyworm.
There are studies, however, of other species of Spodoptera. Most of these are
listed under the generic name Prodenia, by which the majority of the species
were classified before being synonymized with Spodoptera.







Barth (4) described the scent glands of S. ornithogalli, and Hammad and
Jarczyk (19) reported on the morphology and histology of scent glands in S.
littoralis (Boisduval) (asP litura), a closely related species found in Africa and
the Middle East.
Many morphological studies have been done onS. litura (Fabricius), an eco-
nomically important species in India, Southeast Asia, and some of the Pacific
Islands. Various parts of the adult nervous system have been described by Sri-
vastava (42, 43) and Mathur (32). The larval nervous system has been de-
scribed by Bahadur and Srivastava (2, 3) and Srivastava (44). Srivastava and
Mathur also described the morphology of the cephalic and prothoracic glands
in mature larvae (45), and the musculature of the head capsule in mature larvae
(46). Jefferson and Rubin (23) clarified the description of the female sex pher-
omone gland. Mathur (30) described the morphology of the excretory system
in larvae. Abnormal variations in wing venation were described by Bhattach-
erjee and Raghaven (5).
The morphology and anatomy of mature larvae of S. littoralis (as Prodenia
litura) was described by Hassan et al. (21). Murad (33) described the muscu-
lature of the sucking pump of S. mauritia (Boisduval). The male and female
genitalia of S. mauritia acronyctoides Guenee and S. abysinia Guenee were de-
scribed by Chatterjee (12).
Callahan's work on the morphology and histology ofHeliothis zea (7) was
particularly useful, and many of his techniques were followed in this study. The
morphology of reproductive systems and mating in two other noctuids, Pseu-
daletia unipuncta (Haworth) and Peridroma saucia (Hubner), were compared
to Heliothis zea (9).
Detailed morphological descriptions of reproductive systems of other lepi-
doptera include those of Feltia subterranea (41). Anagasta kuhniella (Zeller)
(36), Pectinophora gossypiella (Saunders) (48) and Dioryctria abietella (D.
& S.) (14). Good histological descriptions also have been given for the repro-
ductive systems ofH. zea (10), A. kuhniella (34), and Choristoneurafumifer-
ana (Clemens) (38).
Bullock and Horridge (6) reviewed the types of sensilla occurring on insects.
Research by Callahan (8) and his associates (11) described sensillae on the an-
tenna of the adult corn earworm, H. zea, as well as giving notes on some other
noctuids. However, the only description of sensillae on the beet armyworm an-
tenna was made by Jefferson et al. (26).
Kuznetsov (29) has summarized the early work on Lepidoptera scale struc-
ture. Gentil (15) used an optical microscope to study the scale arrangement of
the wings of Lepidoptera. Since then, some genera have been studied in more
detail. Use of the transmission electron microscope on Morpho scales (16, 27,
39) showed that the iridescent colors were structural; they resulted not from
pigments, but from light diffracted by ridges on the scales. Yagi (51) found that
in the genus Colias (Lepidoptera: Pieridae), the yellow and/or orange colors
were not structural; he disclosed the presence of round and spindle-shaped ag-







gregations of pigments. Kolyer and Reimschuessel (27) studied the ultrastruc-
ture of the scales of Colias eurytheme Boisduval and found variations in color
and position. This was the first time the scales were studied with the scanning
electron microscope.


METHODS AND MATERIALS

All the moths were reared in the laboratory on an artificial medium (1). The
reproductive organs were removed from the digestive tract, placed in physio-
logical saline, examined, and photographed. Histological studies were made on
4-day-old virgin moths; alcoholic Bouin's was used for fixation, paraffin for
imbedding, and Mallory's triple stain for staining. Observations were made
with a Zeiss Photomicroscope II, using Nomarski differential interference
contrast.
All measurements of wing scales were made with a compound microscope
equipped with a micrometer. Measurements of all scale types represent aver-
ages of 12 scales. The measurements of internal reproductive organs were de-
termined by measuring the structure on photographs, using a millimeter rule
photographed at the same magnification.
Eggs, first instar larva, antenna, wing scales, and the external reproductive
organs of the adults were observed with the SEM (Cambridge Mark II-A). At-
tention was given primarily to sensory structures: genitalia, antennae, legs, etc.
Insects were mounted routinely on a stub with silver base paint and then intro-
duced into a Denton DV-502 high vacuum evaporator with a pressure of 2 x
10-5 TORR. Subjects then were coated with a 2000 thickness of gold before
being transferred to the SEM for observation. A camera (Tetronik Corporation
1:1) with Polaroid film PN/55 4 x 5 was used with the scanning electron
microscope.


DESCRIPTIONS OF ADULT AND DISCUSSION

Antennae
The beet armyworm moth is about 2.2 cm across the wings (Figures 1, 2).
The forewings are mottled grayish, and the hindwings are off-white with dark
scales along the veins and the border. Males (Figure 1) can usually be distin-
guished from females (Figure 2) by the more pointed abdomen of the males.
The antennae of the beet armyworm are setiform with a large number of fla-
gellar segments. There is considerable variation in the number of segments
from specimen to specimen, and even between antennae of a particular speci-
men. The mean number was 65 segments compared to 63 reported by Jefferson
et al. (26). There was little difference in the mean number of segments between







gregations of pigments. Kolyer and Reimschuessel (27) studied the ultrastruc-
ture of the scales of Colias eurytheme Boisduval and found variations in color
and position. This was the first time the scales were studied with the scanning
electron microscope.


METHODS AND MATERIALS

All the moths were reared in the laboratory on an artificial medium (1). The
reproductive organs were removed from the digestive tract, placed in physio-
logical saline, examined, and photographed. Histological studies were made on
4-day-old virgin moths; alcoholic Bouin's was used for fixation, paraffin for
imbedding, and Mallory's triple stain for staining. Observations were made
with a Zeiss Photomicroscope II, using Nomarski differential interference
contrast.
All measurements of wing scales were made with a compound microscope
equipped with a micrometer. Measurements of all scale types represent aver-
ages of 12 scales. The measurements of internal reproductive organs were de-
termined by measuring the structure on photographs, using a millimeter rule
photographed at the same magnification.
Eggs, first instar larva, antenna, wing scales, and the external reproductive
organs of the adults were observed with the SEM (Cambridge Mark II-A). At-
tention was given primarily to sensory structures: genitalia, antennae, legs, etc.
Insects were mounted routinely on a stub with silver base paint and then intro-
duced into a Denton DV-502 high vacuum evaporator with a pressure of 2 x
10-5 TORR. Subjects then were coated with a 2000 thickness of gold before
being transferred to the SEM for observation. A camera (Tetronik Corporation
1:1) with Polaroid film PN/55 4 x 5 was used with the scanning electron
microscope.


DESCRIPTIONS OF ADULT AND DISCUSSION

Antennae
The beet armyworm moth is about 2.2 cm across the wings (Figures 1, 2).
The forewings are mottled grayish, and the hindwings are off-white with dark
scales along the veins and the border. Males (Figure 1) can usually be distin-
guished from females (Figure 2) by the more pointed abdomen of the males.
The antennae of the beet armyworm are setiform with a large number of fla-
gellar segments. There is considerable variation in the number of segments
from specimen to specimen, and even between antennae of a particular speci-
men. The mean number was 65 segments compared to 63 reported by Jefferson
et al. (26). There was little difference in the mean number of segments between
















">!


Figure I. Beet armyworm moth, male.



\


wr
/~

V'


Figure 2. Beet armyworm moth, female.

the sexes, but there was some difference in the length and width of antennal
segments between male and female (Table 1).
The basal segments of the antennae are short. The segments elongate dis-
tally, reaching their greatest length at about the midpoint of the antenna, then
decreasing gradually in length to the end. The diameter of the segments de-
creases progressively from the base to the tip of the antenna. All antennal seg-
ments of the male are shorter than the comparable ones of the females (Table
1), which results in a longer overall length for the female antenna.


J






Table 1. Comparison of antennal flagellar segment length in beet armyworm
(n=6 for each sex).

Length (p) Width (i.)
Item mean range mean range
Females
Proximal 125.3 112-144 164.0 114-180
segments
Middle 132.8 127-139 100.0 91-108
segments
Distal 88.8 84-91 63.2 57-72
segments
Males
Proximal 101.0 91-110 141.6 129-151
segments
Middle 122.7 111-132 114.7 96-140
segments
Distal 77.5 74-86 58.3 50-64
segments



The dorsal surface of the flagellum is covered by overlapping scales (Figure
3). Rows of scales oriented diagonally across each segment cover the dorsal
surface of the antenna. Slightly more than half of the antennal circumference is
covered with scales at the base of the antenna. Progressing distally, more of the
antennal circumference is covered with sensilla until, near the tip, two-thirds
the circumference is covered with sensilla.
Most sensilla are found on the ventral surface of the antennal flagellum (Fig-
ures 4, 5). At least six distinct kinds of sensilla were recognized, some of which
can be classified into subtypes. All dimensions given are means of 12 measure-
ments (Table 2).


Table 2. Measurements and proposed functions of sensilla on beet armyworm antenna.

Diameter
Sensilla types Length tI* at base L*
Sensilla coeloconica 9.6
Sensilla auricillica 12 4.8
Sensilla styloconica 15.6 7.2
Trichodea types 1,2 17-29 1-2
Trichodeatype3 38-58 2-5
Trichodea type 4 84-125 4-5
(d only)
Chaetica 6 55-123 5-10
Chaetica 9 43-91 5-5.5
Bohm bristles 9 24-39
Bohm bristles S 17-23
*n=12


























Figure 3. Dorso-lateral view of antennal segment showing convergence of scale surface
with sensory surface. Distal portion of antenna with dorsal surface to the right (X850).


c-
4.-~~~ r


Figure 4. Lateral view of the ventral surface of the basal portion of antenna (X650).
































Figure 5. Most distal segment of the antenna, showing sensors covering most of the
circumference (X 1300).



Bohm bristles (Figures 6, 7). The Bohm bristles are spine-like sensilla found
only on the scape and pedicel. They taper more sharply than the sensilla chae-
tica of the flagellum. Two types of Bohm bristles occur: short ones (type 1),
which are numerous; and long ones (type 2), which are less numerous, are
evenly dispersed among type 1, and have a socket and sclerotized ring at the
base. Bohm bristles are longer in females; their average length varies from
24-39/ compared to 17-28. in males.
On the scape, bristles are concentrated on four domes: two large domes lat-
erally, and two small ones, one ventral and one dorsal. On the pedicel, bristles
occur only on two lateral domes near the intersegmental area between the ped-
icel and the first flagellar segment.
Sensilla chaetica (Figures 8, 9). The sensilla chaetica are blunt spines set in
a membranous socket on the flagellar segment. Magnification (at 6200X, Fig-
ure 10) shows that the surface of the spine is covered with radial ridges or stria-
tions.
Sensilla chaetica have a fixed position on both male and female antennae.
Two chaetica are located on the scale side (dorsal) and are the only sensillae
occurring there. One chaeticum is always located on each side of the ventral
surface at the convergence point of the scale side with the sensory side. Sensilla
chaetica are positioned at about the middle of the length of each segment. Their






























Figure 6. Bohm bristles on scape dome of female (X900).




rnA M t -OO'

ilkI,'iftfi


Figure 7. Close-up of Bohm bristles on scape dome of female (X2400).
























Figure 8. Chaeticum and trichodea on segment near base of antenna (X2600).


;VA


Figure 9. Close-up of chaeticum on the antenna (X6500).

9































Figure 10. Close-up of a large chaeticum, showing radial striations (X6200).


angle with the segment is about 350. The basal segments have only one chae-
ticum on the sensory or ventral side. Two chaetica occur on the sensory or ven-
tral surface at approximately the 20th segment, making a total of six chaetica
per segment.
The longest chaetica on both male and female moths are located on each side
of the antenna at the convergence point of the scale side with the sensory side.
The chaetica of the male are longer, measuring approximately 108 / at the base
of the antenna, reaching 132p towards the middle and tapering to 94/) at the
distal end. Chaetica on the female are 77/. at the base of the antenna, are 91 I
near the middle, and taper to 72p. at the tip.
Chaetica on the ventral surface of males measure from 77[p at the end of the
antenna to 89bp near the middle and 79/. at the tip. The same chaetica on the
females are 43 p, 79)L, and 65pL respectively. The angle of chaetica on the ven-
tral surface ranges from 450 to 800 on both males and females.
The chaetica on the scale or dorsal surface of the antenna are more consistent
in length and take less angle in relation to the antennal segment than any of the
other chaetica. These chaetica range from 48p. long at the base of the antenna
to 67p. at the tip. The angle is 150 to 350 in relation to an antennal segment.
These chaetica originate at the distal end of the first row of scales.
Sensilla trichodea. These sensilla probably play a role in pheromone detec-
tion. The most numerous sensory hairs on the antennae can be separated into
four types. Type I consists of short, porous trichodea having pores arranged in








rows. The pores originate dorsally on the sensillum and continue a distal down-
ward orientation to the ventral part of the sensillum (Figure 11). They measure
15-20/. in length and 1-2/z in diameter at the base. Callahan (8) called them
stubby basiconica. Type 2 consists of long porous trichodea measuring 20-30/
in length and 1-2g in diameter at the base. The pore rows originate on the ven-
tral part of the sensillum and extend on both sides of the sensillum in a dorso-
distal direction until the two rows converge at the mid-dorsal point (Figures 12,
13). Both types of porous trichodea are thin-walled and both are randomly ar-
ranged on the sensory side of the antenna. Type 3 consists of nonporous tricho-
dea (Figure 14). They are thick-walled and measure 38-58/ long and 2-5t/ in
diameter at the base. These sensilla are sharply pointed and arranged randomly
over the entire sensory surface of both male and female antennae. Type 4 con-
sists of extremely long trichodea found only on the male beet armyworm moth,
arranged in six rows per segment with five to six trichodea per row, each tri-
chodea measuring 84-125t/. Three rows originate ventro-laterally on each side
of the antenna at the convergence point between the scale side and the sensory
side. The long trichodea orient diagonally in rows.
All of the other sensilla types are arranged centrally between the rows of long
trichodea. Antennal segments bearing the long trichodea rows extend from the
base of the antenna to approximately the 40th segment. Sensilla on the remain-
ing segments are comparable to those on the female antenna. The ultra-struc-
ture of the nonporous trichodea (type 3) shows a fluted configuration arranged
circularly (Figure 14).


Figure II. Short porous trichodae (X9600).


































Figure 12. Long porous trichodea (X4000).


Figure 13. Long porous trichodea (X12,000).


12
































Figure 14. Non-porous trichodea (X6200).
Figure 14. Non-porous trichodea (X6200).


Sensilla coeloconica (Figure 15). These sensilla have been referred to as pit
peg or picket-fence sensors (8). Each sensillum consists of a porous peg with
inward slanting spines oriented circularly around its periphery. Twelve to fif-
teen spines are arranged in a circular fashion with a fluted peg in the center.
Spines curve inward toward the tip of the peg. Diameter of the pit is about
9-10O on both male and female antennae. Pits occur randomly over the sensory
surface of the antenna with six to ten per segment.
Sensilla auricillica. This type of sensillum has been called spoon sensor (17)
and shoe-horn sensor (8); however, sensilla auricillica, as used by Jefferson et
al. (26), is more consistent with other Latin terms. Sensilla auricillica are ear-
like or spatula-shaped sensors averaging 12[. long and 5/L wide. Two to four
occur per segment on both male and female. The wall is thin and porous. These
sensilla are consistently located distal to the chaetica which are located at the
convergence point of the sensory side with the scale side of the antenna (Fig-
ures 16, 17).
Sensilla styloconica (Figure 18). The sensilla styloconica are cone-shaped
sensory structures mounted at the apices of stout cuticular pegs. Callahan (8)
called them taste rods. There is only one per segment, the size ranging from
16L1 long on the basal segment to 29/1 on the distal segment and 7.2jL in diam-
eter. They occur at the distal end of each segment in the center of the sensory
side.





















Figure 15. Sensilla coeloconica (X6000).

mF m l[g~


Figure 16. Sensilla auricillica and button-like sensor (X6400).

14


































Figure 17. Sensilla auricillica (X6400).


Figure 18. Sensilla styloconica (X4000).







The lack of neuroelectrophysiological information makes it impossible at
this time to assign reasons for morphological arrangements of the sensilla, and
consequently one can only conjecture about the placement of certain sensilla
on the antennae.

Wings
The wings can be differentiated into zones based upon the types of scales
found there. These zones do not correspond with wing venation. Approximate
zones for both sexes and both wings (dorsal and ventral) are shown in Figure
19. In general, the zones are similar on both wings, dorsally and ventrally, and
are similar in both sexes. An exception is the ventral surface of the forewing,
which will be discussed later. Zone 1 usually takes up the anterior one-fourth
of each wing and zone 2 covers the remainder of the wing. The third zone forms
the border and consists of three to five rows of scales.








7-12
ED 3


Figure 19. Zonal division of wings. Left: dorsal surface of forewing (top) and hindwing
(bottom), showing zonal division for both males and females. Right: ventral surface.
Forewing of male at top and female at center. Hindwing of both male and female, bot-
tom.
























Figure 20. Dorsal forewing scales in zone 1 (X230).


Dorsalforewing. Scales found in zone 1 (Figure 20) of both male and female
moths gradually increase in width from the shaft to the tip. They are serrate at
the tip with 3 to 6 points in the males and 4 to 6 in the females. Average lengths
are 292L and 280tL in males and females, respectively. Average width is the
same (41 g) for both sexes. Pigmentation is more heavily concentrated down
the mid-line and the outer margin of the scale and across the apex. The scales
in the female are darker than in the male.
There are two types of scales in zone 2. One type is similar to those in zone
1 in that the scales gradually increase in width from the base to the apex. The
length and width of this type is 2621. x 47> for males and 276/ x 56I for fe-
males. Scales are serrate at the tip with 5 to 6 points for males and 5 to 7 for
females. Heaviest pigmentation is concentrated along the mid-line from the
shaft to the distal end of the scale and across the apex.
Interspersed under the serrate scales are the basal scales. These are blunt-
tipped scales 120/1 x 45p, (males) and 134/, x 50g (females). The blunt tip may
be indented at three or four points in the females. There is less pigmentation in
these scales than in the serrate scales (Figure 21).
The border scales are confined to three to five rows on the outer edge of the
wing. These scales are elongate, and the shaft comprises approximately half of
the length. The width gradually increases from the shaft to the tip, and both
shaft and scale are pigmented. Scales are larger in males, measuring 610L x
78A with 5 to 9 points compared to 470/ x 53/1 with 4 to 5 points in the female
border scales. Width of the shaft is 7.2/1 for males and only 5.0/1 for females
(Figure 22).
Ventralforewing. There are three zones in the ventral forewing of both male
and female moths. Zone 1 covers about one-fifth of the wing area and zones 2
and 3 about two-fifths each. The only difference between males and females is





















Figure 21. Dorsal forewing covering and basal scales in zone 2 (X230).


Figure 22. Border scales on dorsal forewing (X230).


that zones 1 and 3 are adjacent at the base of the wing in the males, while in the
female, zone 2 completely separates zones 1 and 3 (Figure 19).
Scales found in zone 1 of both male and female moths gradually increase in
width from shaft to tip. They are serrate at the tip, with 4 to 6 points in the males
and 3 to 5 points in the females. Average lengths are 312jL and 251 in males
and females, respectively. Average widths are 56g and 44g, respectively (Fig-
ure 23).
There are two types of scales in zone 2. One type is serrate, similar to those
in zone 1, with 6 to 7 points for males and 4 to 6 points for females. The length
and width of this type scale is 280g x 50tL for males and 307p x 49/ for fe-


A%, v-


now y-'

























Figure 23. Scales on ventral forewing in zone 1 (X230).


NWW E-- -
Figure 24. Basal scales and covering scales on ventral forewing in zone 2 (X230).



males. The second type consists of basal scales which are interspersed under
the serrate scales. These scales are shorter and blunt at the tip (Figure 24), with
a slight inward taper. Average measurements of these scales are 169/ x 52/
and 140/ x 51/x in males and females, respectively.
Covering scales in zone 3 are similar in both males and females. They are
blunt tipped, but there are sometimes indentations in females (Figure 25). The
ultrastructure is shown in Figure 26. Measurements are 315 L x 55gt and 308/z
x 51 p. in males and females, respectively. There are blunt basal scales under
the covering scales in males. Their measurements are 96p/ x 48jL. There is no
evidence of basal scales in females.








r~ll.1


Figure 25. Scales on ventral forewing in zone 3 (X230).


Figure 26. Ultrastructure of scales in zone 3 (X5700).


There is a sac-like structure (Figure 27) covered with spine-like scales at the
posterior base of zone 3 where the forewing and hindwing are joined. A sexual
dimorphism characteristic was found: in females the scales are smooth and are
larger at their base (Figure 28), while in males the scales are stronger and have
about the same diameter for the entire length (Figure 29). The function of the
sac-like structure is not known, but it may minimize friction between the wings
and facilitate the movements of both wings.


rzr3'-- --- --i 7




































Figure 27. Spine-like scales on posterior base of ventral forewing on sac-like structure
and regular scales in zone 3 (X200).


Figure 28. Scales on anterior anal area of
the forewing (female, ventral) (X2700).


Figure 29. Scales on anterior anal area of
the forewing (male, ventral) (X2000).







Dorsal hindwing. There are two zones in both males and females. Zone 1
covers the anterior one-fifth of the hindwing and zone 2 takes up the remainder.
The anterior and posterior edges of the hindwing have many piliform (hair-like)
scales varying from 600/ to 1200g long and 3.5g to 6g wide. Only the males
have these piliform scales interspersed in both zones 1 and 2 (Figure 30); there
are none in the females in either zone. Covering scales are mostly light gray or
white except the scales on the veins, which have darker pigmentation.
The covering scales in zone 1 are serrate, with 2 to 5 points in males and 4 to
6 points in females. Pigmentation in zone 1 is darker than in zone 2. The meas-
urements are 228tL x 52/t for males and 252gi x 58. for females. The basal
scales are blunt-tipped and interspersed underneath the covering scales. Aver-
age measurements are 138/ x 50ju.
The covering scales in zone 2 are serrate, with 2 to 4 points for males and 4
to 6 points for females (Figure 31). Their average measurements are 200g x
55[/ (males) and 238[ x 53g (females). White scales are predominant. There
is no pigmentation in the females, and a slightly dark pigmentation in the
males. Blunt-tipped basal scales are interspersed beneath the serrate scales.
Their average measurements are 170/z x 48/.
The border scales are serrate, with 3 to 5 points in the males and 4 to 5 points
in the females. The shaft is one-half the total length of the scale. The scales
vary in length from 438/ to 860/ in males and 425/ to 854Ai in females. The
average width is 40k. in males and 64g in females. The scales are heavily pig-
mented. The width of the peduncle varies from 4.5/t to 6L. The most distin-
guishing characteristic separating males from females is the frenulum spine
number: there is only one in the males but there are three and sometimes four
in the females.


Figure 30. Dorsal hindwing: scales in zone 1 and piliform scales (X230).


























Figure 31. Dorsal hindwing: scales in zone 2 (X230).

Ventral hindwing. The zonal division is similar to that of the dorsal surface.
Covering scales in zone 1 are serrate, with 4 to 5 points for both sexes (Figure
32). Their measurements are 252i/ x 48A in males and 225/1 x 51 g in females.
The scales are pigmented. The basal scales are blunt tipped and measure 101
x 49)u.
All of the scales in zone 2 are white. The covering scales are serrate, with 3
to 5 points in males and 3 to 4 points in females. Lengths of the scales are much
shorter in females compared to those of males (125x to 240/) but the width is
approximately the same, 50/L in males and 53/1 in females. The basal scales are


Figure 32. Ventral hindwing: scales in zone 1 (X230).



























Figure 33. Ventral hindwing: scales on zone 2 (X230).


blunt tipped and are interspersed beneath the covering scales. Their measure-
ments are 100pL x 51 /u in males and 103/t x 47/L in females (Figure 33).
There are four colors of scales: orange, white, gray, and black, with all var-
iations between the last two. The color is not structural but is caused by pigment
grains inside the scale. The white scales do not contain any pigment. At low
magnification there are no apparent differences in form of different colored
scales; but when viewed at 5400X, the upper surfaces of the orange scales have
higher longitudinal ribs, and the cross ribs are consistently circular and accen-
tuated (Figure 34). The gray or black scales have relatively smooth, shallow
grooves between the ribs, and the cross ribs have no regular pattern (Figure 35).
















Figure 34. Ultrastructure of orange scale showing high longitudinal ribs and circular
cross-ribs (X5400).























Figure 35. Ultrastructure of gray scale showing shallow grooves and irregularly pat-
terned cross-ribs (X5400).


Figure 36. Ultrastructure of scale on ventral hindwing in zone 2, showing smooth
groove without perforations (X5700).


Figure 37. Ultrastructure of border scale on ventral hindwing, showing smooth groove
with perforations (X5700).







Preliminary examination of the ultrastructure of scales at magnification in
excess of 5,000X revealed differences that offer possibilities for further classi-
fication of scale types. There are distinct differences in the structure of ribs and
cross ribs. The groove is smooth, either without perforations (Figure 36) or
with perforations in some scales (Figure 37). The groove in others is perforated
with numerous large openings (Figure 38). The cross ribs can be straight (Fig-
ure 38) or curved (Figure 39). Another variation found in border scales on the
forewing is a thickening at every third or fourth rib. A comparative study of the
ultrastructure of wing scales of various families of moths could reveal some
meaningful information on relationships throughout the order.


Figure 38. Ultrastructure of the scale on dorsal forewing in zone 2, showing straight
cross-ribs (X5700).

--d -


mrai"_4PA;qFWMM


Figure 39. Ultrastructure of scale on dorsal hindwing in zone 2, showing curved cross-
ribs (X5500).


"L1T)II"-~ I






Scent Glands


The scent glands are situated ventrally in the non-sclerotized area between
the eighth and ninth abdominal segments (Figure 40), which is contrary to
Hammad's report that the glands covered the ninth abdominal segment of the
beet armyworm (21). The scent glands are exocrine glands derived from epi-
dermis, and are class 3 gland cells as defined by Noirot and Quennedey (35).
They form a typical ventral eversible sac as found in other species studied in the
Amphipyrinae, in contrast to the dorsal sac or fold occurring in the Plusiinae
and the scent ring found in the Cucullinae (25).
The drawing of the scent gland (Figure 41) shows glandular cells and the
wavy, spongy surface of the scent gland. The diameter of the scent glandular
cells is about 10-15/A. The wavy surface of the gland area (microvilli) indicates
that when the tip of the abdomen is extruded, the glandular cells will expand
fully and provide the maximum surface for release of pheromone. The scent
gland of the beet armyworm is therefore similar in location and structure to that
ofSpodoptera ornithogalli, described by Barth (4).



VllthI Figure 40. (left) Location of the scent gland
in the intersegmental area between the ninth
sternite (center) and the eight sternite (sur-
rounding the ninth sternite). Tip of abdo-
men would be at center left. Dark shading
indicates sclerotized area.

Figure 41. (below) Cross section of scent
gland (close-up of lower portion of Figure
40). Drawing shows wavy surface of the
scent gland and glandular cells underneath,
with eighth abdominal sternite at the bot-
.07mm tom.



IXth






Reproductive Organs

The genital complex of lepidopteran females involves the seventh through
tenth abdominal segments. The tenth abdominal segment of S. exigua is mod-
ified by two lateral plates which serve as an ovipositor. These plates have three
types of sensilla: trichodea, button-like, and sensory hairs. The external geni-
talia of the male consists of the vinculum, which lies ventral to the aedeagus.
The left and right arms are actually a single piece forming the sternum of the
ninth abdominal segment. The tergal area of the ninth segment, called the teg-
umen, is fused with the coxosternal arc, the vinculum, to form the base of the
male genitalia. The paired claspers are appendages of the ninth segment and
articulate at the coxopodite area of the vinculum. The uncus is part of the tenth
tergum. Some of the types of sensilla found on the antennae are also found on
the male genitalia: for example, chaeticum and trichodea. The ultrastructure of
the scales show similar longitudinal ridges and transverse veins as found in the
wing scales but without the holes.
The striking difference between the male and female genitalia is that many
more scales are found around the male genitalia, while more sensilla are found
on the female. Why sensors are much more numerous in the female genitalia is
not known; however, it is likely associated with the necessity of the female to
locate a suitable oviposition site, using the ovipositor as a test organ.
The female reproductive system consists of a pair of ovaries which open to a
pair of lateral oviducts (Figure 42). Each ovary is composed of four ovarioles
(or egg tubes). Ovariole development of the oocytes is panoistic. Maturity of
developing eggs is indicated by the color: white at the beginning, then pink-
purple, and finally greenish when the eggs are mature. The two lateral oviducts
join the median oviduct, which opens to the gonopore (oviporus and anus) at
the ninth segment. Two other glands open to the gonopore:
1) The paired accessory glands, consisting of small, long tubules, which are
enlarged at the base to function as reservoirs of the accessory glands, and
which open to a median duct joining the gonopore.
2) The spermatheca, also opening to the gonopore, which is composed of
four parts:
a) large lobe utriculuss) of spermatheca (Figure 42i)
b) small lobe (lagena) (Figure 42h)
c) upper loop of ductus receptaculi (spermathecal duct) (Figure 42j)
d) convoluted area and lower loop of ductus receptaculi (Figure 42k)
The utriculus and the lagena form paired lobes which taper posteriorly to
form separate ducts that eventually converge to form a single duct just anterior
to the looped area of the ductus receptaculi. The utriculus is much larger than
the lagena. For recognition, the lagena must be filled with sperm to cause ex-
pansion of the lagena wall. Two separate glands were found to extend from the
anterior end of the utriculus. Each gland was connected to separate, unidenti-
fied reservoir-like structures. Subsequent studies will attempt to identify and
determine the function of these structures.


























































Figure 42. The female reproductive system:
a. bursa copulatrix
b. vaginal duct
c. vulva
d. ovaries
e. lateral oviduct
f. median oviduct
g. oviprous and anus (gonopore)


h. lagena
i. utricularis
j. spermathecal duct
k. lower loop of ductus receptaculi
1. accessory gland
m. reservoir or accessory gland






























3mm

Figure 43. The spermatop
a. capsule
b. neck
c collum
d. sperm bun


There are two ducts at the base of the sper-
matheca, one opening to the gonopore, and
the other leading to the base of the bursa
copulatrix.
The gonopore, which consists of oviporous
and anus, is on the ninth abdominal segment,
while the copulatory vulva opens on the eighth
abdominal segment.
The bursa copulatrix is the most conspicu-
ous organ in the female insect. The sides are
twisted and ridged with sclerotized ribs. At
C the top of the sac-like organ is the site of cap-
sule formation of the spermatophores. The
most spermatophores found in the bursa co-
pulatrix was four. The spermatophore is com-
posed of a capsule and a sclerotized tube or
collum (Figure 43). The neck-connection be-
tween the capsule and the collum is elbowed,
making the capsule vertical to the tube. The
capsule loses its spherical shape and becomes
)hore: flattened when the sperm are released through
the seminal duct, but the collum remains a
hard, sclerotized structure during the lifetime
dles of the female.


Table 3. Measurements of female internal reproductive organs and spermatophore.


Organs
Accessory glands
Reservoir of accessory glands
Spermatheca utriculuss)
Lagena
Spermathecal duct
Lagena duct
Lower loop of ductus receptaculi
Bursa copulatrix
Ovarioles
Vaginal duct
Seminal duct
Oviductus communis
Lateral oviduct
Spermatophore
Capsule
Neck
Collum


Mean length (mm)*
5.5
.8
1.2
.40
1.6
1.6
.6
3.0
29.1
1.5
1.9
2.5
1.8

1.2-2.0
1.4-2.0
3.0-4.0


1.2 (width)






1.0-1.3 (width)
.2-.3 (diameter)
.2-.3 (diameter)






Table 4. Measurements of male internal reproductive organs.
Organs Mean length (mm)*
Seminal vesicles 1.5
Vas deferens 2.0
Accessory glands 24.0
Ductus ejaculatorius duplex 6.1
Ductus ejaculatorius simplex 51.2
Testis 1.2 (in diameter)
*n=6


The adult male reproductive system has only one fused testis as compared to
two separate testes in the last larval instar. The two large bean-like testes in the
larval stage shrink and fuse in the prepupal stage as the larva shrinks and de-
creases in size. The moth tes-
tis is located around the fourth
and fifth abdominal segments.
It is spherical and rose-col-
ored. The paired seminal ves-
icles lead from the testis to the
vas deferens, which opens into
the ductus ejaculatorius du- / A
plex near the midpoint (Figure D
44). The seminal vesicles are
about three times as wide as
the vas deferens. Both are
creamy-white, as are the re-
maining glands and ducts of E
the organs. The two accessory
glands (as two parallel ducts)
are joined together for their
entire length before they open
into the basal end of the duc-
tus ejaculatorius simplex. The
latter fuses into the ductus eja- G
culatorius simplex, which is
the longest duct of the repro- 5mm
ductive organ. About one-
sixth of the distance from the Figure 44. The male reproductive system:
beginning, there is an enlarge- a. testis
ment of the duct. The ductus b. seminal vesicle
ejaculatorious simplex leads to c. vasdeferens
d. accessory gland
the endophallus. The aedea- e. ductus ejaculatorius duplex
gus is the sclerotized part sur- f. ductus ejaculatorius simplex
rounding the endophallus. g. aedeagus







EGGS AND LARVAE

Eggs are oblong spheroids, circular in cross section, with a diameter of ap-
proximately 0.42 mm. They are greenish when oviposited, turning cream-col-
ored within a few hours, and finally becoming dark just before hatching,
because of the black color of the larval head. Eggs are laid in clusters of five to
more than one hundred. The masses of eggs are covered with whitish scales
from the tip of the female abdomen, except that egg masses oviposited later are
often not covered, because the female moth has lost almost all the setae at the
abdominal tip (Figure 45). The micropyle, located at the top of the egg, is sur-
rounded by a petal-like pattern with the number of petals varying from 7 to 11
(Figure 46). The whole egg is composed of many concave surfaces delineated
by higher ridges (Figure 46). Many tiny pores, called aeropyles, can be seen
distributed at the edges of the ridges at 1300X (Figure 47). These aeropyles
play a principal role in gas and moisture exchange (22).
There are five larval instars and occasionally six. The first instar larva is
about 1 mm long with a whitish body and black head. The body color is highly
variable from specimen to specimen in later instars, ranging from light green to
olivaceous to near black. The head becomes a lighter brown, with a number of
near-white reticulations on the epicranium. The width of the first instar head
capsule is 0.25 mm (n=6). Full grown larvae measure from 30 to 35 mm in total
body length.


Figure 45. Beet armyworm eggs partly covered with scales from tip of female abdomen
(X120).

























Figure 46. Apex of egg, showing micropyle and chorion design (X850).

of ^^ '.-"g


Figure 47. Egg surface, showing aeropyles (pores) in edge of ridges (X 1300).































Figure 48. Overall view of anterior portion of first instar larva (X 160).


Only the first instar larva (Figure 48) was examined with the scanning elec-
tron microscope, and its description follows. The six ocelli are arranged in a
semi-circular position and are unequal in size: the third ocellus is the largest,
while the first and the sixth ocelli are smaller than the others. Setae on the head
are more pointed than those on the body, with lengths varying from 0.02 to
0.08 mm. These setae are usually curved or bent near the tip, while the body
setae are more or less straight and are thicker. The body setae are also inserted
on a raised pinaculum which has a much larger diameter and is chalaza-like,
whereas those on the head have only a simple peritreme. There are numerous
tiny spicules on the body, evenly distributed almost everywhere except on some
transverse folds and on the intersegmental positions of the larva.



CONCLUSIONS

On the basis of this research, the following morphological distinctions have
been determined for the beet armyworm:
1. The female antennae are longer than male antennae.
2. There are six morphologically distinct types of sensilla on the antennae
of each sex. The male, however, does have a distinct pattern arrangement
of the long sensilla trichodea.







3. Wing areas can be divided into distinct zones based on types of scales.
4. Scent glands are present in the ventral intersegmental area between the
eighth and ninth abdominal segments.
5. The female ovary is composed of four ovarioles.




LITERATURE CITED

1. Bacheler, J. S., and T. C. Emmel. 1975. Genetic control of maculation hindwing
color inApantesisphalerata (Arctiidae). J. Res. Lepidop. 13(1):49-56 (1974).
2. Bahadur, J., and B. B. L. Srivastava. 1968. Studies on the nervous tracts in the
brain of the larva of Prodenia litura Fabr. (Lepidoptera:Noctuidae). Acta. Zool.
Stockholm 49:163-75.
3. 1968. The nerves of the thoracic segments of the larva of Prodenia litura
Fabr. (Lepidoptera:Noctuidae). J. N. Y. Entomol. Soc. 74(4):168-79.
4. Barth, R. 1961. Die Druesenorgane des Weichens von Prodenia ornithogalli Gue-
nee (Lepidoptera:Noctuidae). Ann. Acad. Brasil Cienc. 33:429-33.
5. Bhattacherjee, N. S., and M. V. Raghavan. 1968. Some abnormal variation in the
wing venation of Prodenia litura Fabr. (Lepidoptera:Noctuidae). Indian J. Ento-
mol. 29(1):98-99.
6. Bullock, T. H., and G. A. Horridge. 1965. Structure and function in the nervous
systems of invertebrates. W. H. Freeman and Co. San Francisco and London.
1719p.
7. Callahan, P. S. 1958. Serial morphology as a technique for determination of repro-
ductive patterns in the corn earworm, Heliothis zea (Boddie). Ann. Entomol. Soc.
Amer. 51(5):413-28.
8. 1969. The exoskeleton of the corn earworm, Heliothis zea
(Lepidoptera:Noctuidae) with special reference to the sensilla as polytubular die-
lectric arrays. Univ. Georgia Coll. Agr. Exp. Sta. Res. Bull. 54:1-105.
9. Callahan, P. S., and Joan B. Chapin. 1960. Morphology of the reproductive mem-
bers of the family Noctuidae, Pseudaletia unipuncta and Peridroma margaritosa,
with comparisons toHeliothis zea. Ann. Entomol. Soc. Amer. 53(6):763-82.
10. Callahan, P. S., and Thomas Cascio. 1963. Histology of the reproductive tracts and
transmission of sperm in the corn earworm, Heliothis zea. Ann. Entomol. Soc.
Amer. 56(4):535-56.
11. Callahan, P. S., E. F. Taschenberg, and T. C. Carlysle. 1968. The scape and pedicel
dome sensors a dielectric aerial wave guide on the antennae of night flying
moths. Ann. Entomol. Soc. Amer. 61:934-37.
12. Chatterjee, S. N. 1969. The identity ofSpodoptera mauritia acronyctoides, Gue-
nee, S. pecten Guenee and S. abyssinia Guenee (Lepidoptera:Noctuidae) based on
a comparative study of the male and female genitalia. Proc. Nat. Inst. Sci. India
(part B). Biol. Sci. 35(1):45-52.
13. Chlodkovky, N. 1884. Uber die Hoden der Lepidoptera. Zool. Anz. 7:564-8.






14. Fatzinger, C. W. 1970. Morphology of the reproductive organs ofDioryctria abie-
tella (Lepidoptera:Pyralidae [Phycitinae]). Ann. Entomol. Soc. Amer. 63(5):1256-
62.

15. Gentil, K. 1935. Der Bau der Schillerschuppen von Papilio paris. Entomol. Rund-
shau 52:230-32.

16. 1942. Elekronmikroskopishe untersuchung des feinbaues schillernder
listen von Morpho-schuppen. Z. Morphol. Oklog. der Tiere 38(2):345-55.

17. Griffith, P. 1968. Investigation of insect electromagnetic communication. ERL rep.
No. 68-3. Electronic Res. Lab., Univ. Calif., Berkeley.

18. Hammad, S. M. 1961. The morphology and histology of the sexual scent glands in
certain female lepidopterous moths. Bull. Soc. Entomol. Egypte 45:471-82.

19. Hammad, S. M., and J. H. Jarczyk. 1958. Contributions to the biology and bio-
chemistry of the cotton leafworm, Prodenia litura Fabr. III. The morphology and
histology of the sexual scent glands in the female moth of Prodenia litura Fabr.
Bull. Soc. Entomol. Egypte 42:253-61.
20. Harvey, L. F 1876. Canad. Entomol. 8:54.
21. Hassan, A. S., A. M. EI-T. Shehata, and S. M. Hammad. 1958. The morphology
and anatomy of the mature larvae of Prodenia litura F (Lepidoptera:Agrotidae,
Xenobiinae) Bull. Soc. Entomol. Egypte 42:291-309.
22. Hinton, H. E. 1969. Respiratory systems of insect egg shells. Annu. Rev. Entomol.
14:343-68.

23. Jefferson, R. N., and R. E. Rubin. 1970. Sex pheromones of noctuid moths. XVII.
A clarification of the description of the female sex pheromone gland of Prodenia
litura. Ann. Entomol. Soc. Amer. 63(2):431-3.

24. Jefferson, R. N., H. H. Shorey, and L. K. Gaston. 1966. Sex pheromones of
noctuid moths. X. The morphology and histology of the female sex pheromone
gland of Trichoplusia ni (Lepidoptera:Noctuidae). Ann. Entomol. Soc. Amer.
59:1166-9.
25. Jefferson, R. N., H. H. Shorey, and R. E. Rubin. 1968. Sex pheromones of noctuid
moths. XVI. The morphology of the female sex pheromone glands of eight species.
Ann. Entomol. Soc. Amer. 61(4):861-65.

26. Jefferson, R. N., R. E. Rubin, S. U. McFarland, and H. H. Shorey. 1970. Sex
pheromones of noctuid moths. XXII. The external morphology of the antennae of
Trichoplusia ni, Heliothis zea, Prodena ornithogalli, and Spodoptera exigua. Ann.
Entomol. Soc. Amer. 63(5):1227-38.
27. Kinder, E., and F Suffert. 1943. Ueber den Feinbau Schillernder Schmetterling-
schuppen von Morpho-typ. Biol. Zentr. 63:268.
28. Kolyer, J. M., and Annemarie Reimschussel. 1970. Scanning electron microscopy
on wing scales of Colias eurytheme. J. Res. Lepidop. 8(1):1-15.
29. Kuznetsov, N. Ya. 1915. Fauna of Russia and adjacent countries. Trans. Mercado,
Ed. B. Golek, U.S. Dept. Comm.:148-62.
30. Mathur, L. M. L. 1968. Morphology of the excretory system of the noctuid larvae
Prodenia litura Fabr. and Trichoplusia ni Hbn. Indian J. Entomol. 28(1):61-66.







31. 1969. Morphology of the nervous system of the noctuid larvae Prodenia
litura Fabr. and Trichoplusia ni Hbn. Indian J. Entomol. 29(1):25-33.
32. 1969. Morphology of the nervous system of adult Prodenia litura. Ann.
Entomol. Soc. Amer. 62(3):525-29.
33. Murad, H. 1969. Musculature of the sucking pump ofSpodoptera mauritia Bois-
duval (Lepidoptera:Noctuidae). Proc. Nat. Acad. Sci. India (Sect. B) Biol. Sci.
37(2):135-58.

34. Musgrave, A. J. 1937. Histology of the male and female reproductive organs of
Ephestia kuhniella. Proc. Zool. Soc. London (B), 107:337-64.
35. Noirot, C., and A. Quennedey. 1974. Fine structure of insect epidermal glands.
Annu. Rev. Entomol. 19:61-80.

36. Norris, M. J. 1932. Contributions towards the study of insect fertility. I. The struc-
ture and operation of the reproductive organs of the genera Ephestia and Plodia.
Proc. Zool. Soc. London 3:595-611.
37. 1933. Contributions towards the study of insect fertility. II. Experiments
on the factors influencing fertility in Ephestia kuhniella Z. (Lepidoptera:Phycitidae).
Proc. Zool. Soc. London 4:903-34.
38. Outram, 1. 1971. Morphology and histology of the reproductive system of the male
spruce budworm Choristoieurafumiferana. Canad. Entomol. 102:404-14.
39. Richards, O. G. 1944. Notes and news in entomology (Stereoscopic electron mi-
crographs of Morpho cypris iridescent scales). Entomol. News 55(7): 190-93.
40. Shorey, H. H., and R. L. Hale. 1965. Mass rearing of the larvae of nine noctuid
species on a simple artificial medium. J. Econ. Entomol. 58:522-4.
41. Snow, J. W., and P. S. Callahan. 1968. Biological and morphological studiesof the
granulate cutworm, Feltia subterranean (F) in Georgia and Louisiana. Univ. Geor-
gia Res. Bull. 42. 23 p.
42. Srivastava, B. B. L. 1967. Nervous system of the head of Prodenia litura (Lepi-
doptera:Noctuidae). Zool. Pol. 17(4):315-22.
43. 1970. Studies on the nervous part, tracts and commissure in the brain of
Prodenia litura Fabr. (Lepidoptera:Noctuidae). ACTA Anat. 74(2):243-66.

44. 1972. Nervous system of abdominal segments of the larva of Prodenia
litura (Lepidoptera:Noctuidae). J. Georgia Entomol. Soc. 7(1):37-50.

45. Srivastava, B. K., and L. M. L. Mathur. 1963. Morphology of cephalic and pro-
thoracic glands of the mature larva of Prodenia litura Fabr. (Lepidoptera:Noctuidae).
Indian J. Entomol. 25:116-22.
46. 1964. Morphology and musculature of the head capsule of mature larva
of Prodenia litura Fabr. (Lepidoptera:Noctuidae). Indian J. Entomol. 26(1):78-91.
47. Virkki, N. 1963. Gametogenesis in the sugarcane borer moth, Diatraea sacchar-
alis (F.) Crambidae. J. Agr. Univ. Puerto Rico 47(2):102-37.
48. Wellso, S. G., and P. L. Adkisson. 1962. The morphology of the reproductive sys-
tem of the female pink bollworm moth, Pectinophora gossypiella Saunders. J.
Kansas Entomol. Soc. 35:233-35.










49. Wilson, J. W. 1932. Notes on the biology of Laphygma exigua Hubner. Florida
Entomol. 16:33-39.
50. __ 1934. The asparagus caterpillar: its life story and control. Univ. Fla. Agr.
Exp. Sta. Tech. Bull. 271. 26 p.
51. Yagi, N. 1954. Note of electron microscope research on pterin pigment in the scales
of pierid butterflies. Annot. Zool. Japonenses27(3):l 13-14.


































All programs and related activities sponsored or assisted by the Florida
Agricultural Experiment Stations are open to all persons regardless of race, color,
national origin, age, sex, or handicap.



This public document was promulgated at an annual cost of $2347 or a
cost of $1.56 per copy to disseminate new basic information on the beet
armyworm.









HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs