Title: Florida Entomologist
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Title: Florida Entomologist
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Creator: Florida Entomological Society
Publisher: Florida Entomological Society
Place of Publication: Winter Haven, Fla.
Publication Date: 1932
Copyright Date: 1917
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Subject: Florida Entomological Society
Entomology -- Periodicals
Insects -- Florida
Insects -- Florida -- Periodicals
Insects -- Periodicals
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Florida Entomologist
Official Organ of the Florida Entomological Society

Vol. XVI SEPTEMBER, 1932 No. 2

THREE NEW APHIDS OF THE TRIBE CHAITOPHORINI*
A. N. TISSOT
Two of the three species of aphids here described were found
feeding on the leaves and twigs of willows in Florida. The third
species is rather common on the leaves of some of the oaks.
CHAITOPHORUS LONGIPES, new species
Alate viviparous female. (Plate II, figs. 1-7.) Prevailing color brown.
Length of body 2.24 mm. Body and appendages armed with long, straight
or slightly curved hairs. Head dark brown; wider than long, without an-
tennal tubercles. Front of head broadly rounded and armed with very
long hairs, some having a length of .136 mm., and arising from rather
large conical bases. Width of head through the compound eyes .381 mm.
Eyes dark reddish-brown with large ocular tubercles. Ocelli large, bor-
dered with very dark brown. Antennae about one-half the length of the
body; the first segment dark brown, the second somewhat lighter brown.
The basal one-third of the third segment yellowish-brown, the remainder
of the third and the whole of the three following segments dark brown.
With the exception of the two basal ones the segments of the anten-
nae are definitely imbricated. All the segments of the antennae with a
few pointed spines, those of the two basal segments shorter and more
curved than the others. The third segment with eight rather small, cir-
cular sensoria arranged in a single row that extends almost the full
length of the segment; the fourth segment with one sensorium; the fifth
with the usual terminal one and the sixth with the usual group at the
base of the unguis. The length of the antennal segments as follows: I,
.095 mm., II, .054 mm., III, .340 mm., IV, .190 mm., V, .177 mm., VI, base,
.095 mm., unguis, .326 mm. Rostrum dark brown; reaching to second
coxae.
Prothorax brown, somewhat lighter than the head; other two thor-
acic segments about same color as the head; wing insertions yellowish.
Prothorax with small, dark brown lateral tubercles, and armed with
numerous prominent hairs situated on conical bases. Wings long and nar-
row; hyaline. Fore wing with stigma and veins yellowish-brown. The
media twice-branched; the radial sector present, only slightly curved. A
row of short curved hairs along the posterior margin of the stigma. Hind
wing with two oblique veins. Legs brown; a small basal portion of the

*Contribution from Department of Entomology, Florida Agricultural
Experiment Station. Published September 20, 1932.











THE FLORIDA ENTOMOLOGIST


femora and the middle portions of the tibiae yellowish-brown, the remain-
ing parts dark brown. The legs rather thickly set with mostly straight
hairs, those of the tibiae being longest. Length of hind tibiae, .775 mm.
Abdomen light brown with dark brown markings. Along each lateral
margin is a row of six dark brown spots more or less circular in outline.
Each of the segments anterior to the cornicles has an elongated dark
brown area on the dorsal surface; between the cornicles and the cauda
are found three dark brown bands extending all the way across the seg-
ments. Dorsal and lateral surfaces of the abdomen plentifully supplied
with long, slightly curved hairs, the longest being about equal in length
to those of the head; the ventral surface with a few very short fine
hairs. Cornicles pale yellowish-brown with the apex somewhat darker
brown; truncate, widest at the base and tapering rather gradually to
the apex. Surface of the cornicles imbricated or faintly reticulated. Width
at the base .136 mm., width at apex .054 mm., length .082 mm. Cauda
distinctly knobbed with a definite constriction and a large cone-shaped
base. Two median and two lateral curved hairs arising from the cauda,
the lateral being much the longer. Anal plate straight or slightly rounded,
with numerous hairs straighter and longer than those of the cauda.
Cauda and anal plate medium brown.
Apterous viviparous female. (Plate II, figs. 8-10.) Prevailing color
brown. Length of body 1.72-2.12 mm. Body and appendages armed with
numerous long hyaline hairs. Head brown with the anterior margin
darker than the remainder. Width of head through the eyes .435-.490 mm.
Width of head much greater than the length. Front margin broad;
straight or slightly rounded. Head with several long hairs arising from
large conical or globular bases. Antennae six-segmented, somewhat over
half as long as the body, armed with a few scattered hairs much shorter
than those of the head. Basal portion of the third segment yellowish-
brown, remainder of the antennae dark brown. Third segment without
sensoria, the usual ones at the apex of the fifth and at the base of the
unguis of the sixth. Segments III to VI definitely imbricated. Length of
antennal segments: III, .286-313 mm., IV, .122-.177 mm., V, .136-.163 mm.,
VI, base, .082-.095 mm., unguis, .272-.299 mm.
Thorax brown with lateral dark brown areas. Prothorax with small
dark brown lateral tubercles. Hairs of the thorax similar to those of the
head and of about the same length. Legs brown with the bases of the fe-
mora slightly lighter than the remaining portions. All segments of the
legs with numerous hairs, those of the tibiae being longest and most
numerous. Length of hind tibiae .707-.775 mm.
Abdomen brown, somewhat lighter than the head and thorax, the lat-
eral margins being darker than the other portions. The hairs on the abdo-
men numerous, those around the margin being the longest found anywhere
on the body. Cornicles truncate, widest at the base and tapering toward
the apex; the width at the base greater than the length. Surface with
faint imbrications. Color of the cornicles yellowish-brown. Cauda definite-
ly knobbed, with a broad conical base and armed with four slightly curved
hairs. Anal plate broad; straight or slightly curved with several curved
hairs. Cauda and anal plate brown, somewhat darker than the abdomen.
Apterous oviparous female. Prevailing color brown, much as in vivi-
parous female. Length of body 2.2 mm. Body more elongate and less ro-










VOL. XVI-No. 2


bust than in apterous viviparous female. Body and appendages with long
hyaline hairs. Head brown, darkest along anterior margin. Frontal mar-
gin straight or slightly rounded. Width through the compound eyes .422
mm. Head with several long hyaline hairs arising from large globular
bases. Eyes reddish-brown with large ocular tubercles. Antennae slight-
ly less than half the length of the body six- or five-segmented (in some
specimens the third and fourth segments only partially divided), armed
with a few hyaline hairs. The first two segments concolorous with the
head, the basal portion of the third yellowish-brown, the remainder of the
segments dark brown. Third and fourth segments without sensoria, the
usual primary ones at the apex of the fifth segment and at the base of
the unguis. Segments III to VI imbricated though III and IV are only
faintly so. Length of antennal segments as follows: III, .157 mm., IV, .128
mm., V, .157 mm.; VI, base, .10 mm., unguis, .30 mm.
Thorax brown, the lateral margins concolorous with the head. Hairs
of thorax about equal in length to those of the head. Legs brown with the
bases of the femora and the middle portions of the tibiae of the first two
pairs of legs lighter than the remaining portions. The hind tibiae consid-
erably swollen with numerous scattered and somewhat tuberculate sensoria.
The hairs of the tibiae much longer than those of the other leg segments.
Abdomen brown, somewhat lighter than the head and thorax. The sur-
face of the abdomen armed with numerous hyaline hairs, those around the
lateral margin being the longest of the body. Cornicles yellowish-brown,
truncate, widest at the base and tapering toward the apex, the surface
faintly imbricated. Cauda short, definitely knobbed and armed with a few
slightly curved hyaline hairs. Anal plate broadly rounded with numerous
hairs. Cauda and anal plate slightly darker than the abdomen.
Type locality: Gainesville, Florida.
Types: Holotype alate viviparous female taken on Salix
longipes Dec. 13, 1928 (F 434-28), deposited in the U. S. Na-
tional Museum Collection, Cat. No. 44308. Morphotype apterous
viviparous female and morphotype apterous oviparous female,
same data as holotype also deposited in the U. S. National Mu-
seum Collection. Paratypes in the collections of the Ent. Dept.,
Florida Agr. Exp. Sta.; of A. A. Granovsky; and in that of the
author. Types selected from eight alate females. Type material
collected by the author.
Notes: This aphid seems to be rather similar to Chaitophorus
pusillus Hottes and Frison but differs from that species in the
following respects: the abdomen is light brown with dark brown
markings instead of yellowish as in pusillus; the stigma of the
wing is long, narrow, and acutely pointed instead of short and
bluntly pointed as in pusillus; it feeds largely on the twigs
whereas pusillus feeds on the leaves. There is another aphid,
Sipha minute n. sp., which feeds upon the willow, often in rather
close association with C. longipes. They can readily be sepa-










THE FLORIDA ENTOMOLOGIST


rated, however, by their general appearance and habits. The
former is much smaller, is yellowish-green and feeds almost
exclusively upon the leaves; the latter is decidedly brown in


2 /


6


~ff~ \\l I P%


7


113-. 19~
19

16







?8

22


241 \


26


"2


New Florida Aphids-Plate II
Explanation of Plate II
Chaitophorus longipes n. sp.
Figs. 1-7-Alate viviparous female; 1, head; 2, antenna; 3, anal plate;
4, cauda; 5, cornicle; 6, wings; 7, stigma.
Figs. 8-10-Apterous viviparous female: 8, head; 9, antenna; 10, cor-
nicle.
Patchia obscure n. sp.
Figs. 11-16-Alate viviparous female: 11, head; 12, wings; 13, cor-
nicle; 14, cauda; 15, anal plate; 16, antenna.
Figs. 17 & 18-Apterous viviparous female: 17, cornicle; 18, antenna.
Figs. 19 & 20-Oviparous female: 19, cornicle; 20, antenna.
Sipha minute n. sp.
Figs. 21-26-Alate viviparous female: 21, head; 22, antenna; 23, wings;
24, cornicle; 25, cauda; 26, anal plate.
Figs. 27-29-Apterous viviparous female: 27, head; 28, antenna; 29,
cornicle.


V .N.T1 s o1


s~~-~--~


I Oft


^









VOL. XVI-No. 2 21

color and rarely feeds on the leaves, being almost always found
on the young and tender stems of the willow.
Collections: Salix longipes, Gainesville, Dec. 13, 1928
(F 434-28 and F 435-28), May 18, 1929 (F 530-29), May 16,
1930 (F 641-30), Sept. 18, 1930 (F 704-30); Salix sp., Ocoee,
July 22, 1932 (F 960-32), (M. R. Brown).

PATCHIA OBSCURA, new species
Alate viviparous female. (Plate II, figs. 11-16.) Prevailing color dark
reddish-brown. Length 1.60 mm. Head very dark brown. Width through
the compound eyes .449 mm. Anterior margin of the head with several
hairs which curve inward; the two middle ones considerably longer than
the others. Eyes black, with prominent ocular tubercles. Ocelli bordered
with black. Antennae six-segmented, about half as long as the body. First
two segments concolorous with the head, remaining segments lighter brown
with the apices somewhat darker than the basal portions. Length of an-
tennal segments as follows: I, .068 mm., II, .054 mm., III, .313 mm., IV,
.190 mm., V, .177 mm., VI, base, .102 mm., unguis, .048 mm. Right an-
tennae with nine sensoria on the third segment, left antenna with eight
sensoria. The sensoria large, circular, and arranged in an even row along
the segment. Fourth segment without sensoria. All the antennal seg-
ments with prominent hairs, these being most numerous on the third,
fourth, and fifth segments. With the exception of the first two segments
the antennae are imbricated. Rostrum reaching to the hind coxae; the
basal and apical portions very dark brown, the mid-portion light brown.
Prothorax brown, about the same shade as the head; anterior margin
about as wide as the head but becoming much wider behind. Posterior
lateral margins of prothorax with prominent tubercles. Meso- and meta-
thoracic segments very dark brown with the lobes black. Wings shaded
with black. Stigma black; the veins of both pairs of wings bordered with
broad black bands, the entire wing surface having a scale-like appearance.
Fore wing with radial sector present though somewhat fainter than the
other veins; media twice-branched; hind wing with both media and cu-
bitus present. Legs entirely brown, the hind pair darker than the other
two. All portions of the legs thickly set with reclining, slightly curved
hairs. Length of hind tibia 1.061 mm.; second joint of hind tarsus .128 mm.
Abdomen reddish-brown, with the lateral margins somewhat darker
than the remainder. Posterior portion with numerous hairs. Cornicles
black; width greater than the length, truncate, somewhat constricted
about the middle. Cauda rounded, almost hemispherical. Anal plate bi-
lobed with the indentation shallow. Cauda and anal plate dark brown,
with long slightly curved hairs arising from conical bases.
Apterous viviparous female. (Plate II, figs. 17 and 18.) Length 2.00
mm. Body and appendages brown. Head dark brown; eyes black with
definite ocular tubercles. Antennae about half as long as the body, six-
segmented; light brown at the base, shading to dark brown at the apex.
Length of segments as follows: I, .074 mm., II, .061 mm., III, .258 mm.,
IV, .190 mm., V, .204 mm., VI, base, .136 mm., unguis, .048 mm. Third and
fourth segments without sensoria; the usual terminal ones on the fifth








THE FLORIDA ENTOMOLOGIST


and sixth. All segments with prominent hairs; third to sixth segments
imbricated. Rostrum brown; reaching to second coxae.
Thorax and abdomen dark brown. Prothorax with prominent pointed
lateral tubercles. Legs brown, hind pair darker than the other two. All
parts of the legs with numerous prominent hairs. Length of hind tibia
1.00 mm. Cornicles black; truncate, much wider than long. Cauda round-
ed, anal plate-bilobed. Cauda and anal plate dark brown with many long
curved hairs.
Oviparous female.-Plate II, figs. 19 and 20. Color entirely brown,
very similar in appearance to the apterous viviparous female. The most
noticeable difference between these two forms is the somewhat swollen
hind tibia of the oviparous female. This segment of the leg bears a few
scattered sensoria.
Type locality: Gainesville, Florida.
Types: Holotype alate viviparous female taken on Quercus
nigra Apr. 18, 1928 (F 355-28), placed in the U. S. National
Museum Collection. Cat. No. 44309. Morphotype apterous vivi-
parous female, Gainesville, Feb. 14, 1929 on Quercus nigra and
Morphotype apterous oviparous female same data as apterous
viviparous female also deposited in National Museum Collec-
tion. Paratypes in the U. S. National Museum Collection and
in the collections of the Entomology Department, Florida Agr.
Exp. Sta.; of A. A. Granovsky, and in that of the author. Type
selected from 30 alate viviparous females. Type material col-
lected by the author.
Notes: This species is one of the most common aphids found
on the oaks in Central Florida. It does not form large colonies
and usually not more than two or three individuals will be found
on a single leaf. The alate females when at rest are very con-
spicuous against the green background of the leaf. The black-
banded wings are folded together roof-like and slightly ele-
vated over the back. Apterous females are sometimes found
but the alate form is greatly predominant.
Collections: Quercus sp., Micanopy, May 13, 1926 (F 125-
26); Monticello, Aug. 31, 1927 (F 260-27), (Walker) ; Gaines-
ville, Apr. 5, 1928 (F 342-28), (Bratley) ; Quercus michauxii,
Gainesville, Apr. 3, 1928 (F 330-28), (Bratley and Tissot);
Quercus nigra, Gainesville, Apr. 18, 1928 (F 355-28), May 14,
1928 (F 388-28), Feb. 14, 1929, (F 467-29); Prunus (?) sp.,
Lake City, May 27, 1897, (Quaintance) ; Liquidembar styraci-
flua, Gainesville, May 13, 1927 (F 231B-27). This last collection
consisted of a single alate female which probably flew to the
sweet gum from oaks growing in the vicinity.









VOL. XVI-No. 2


SIPHA MINUTA, new species

Alate viviparous female. (Plate II, figs. 21-26.) Prevailing color, vari-
ous shades of green; length 0.98 mm. Head dark greenish-brown, margins
brown. Width through the compound eyes .340 mm. Front of head with
four long hairs, the length of the longest at least equal to the combined
lengths of the first two antennal segments. Eyes dark reddish-brown with
large ocular tubercles. Ocelli bordered with dark brown. Antennae five-
segmented, nearly as long as the body, with a few long, prominent hairs.
First two segments greenish, the remaining segments dusky with the apex
of the fourth, the basal portion of the fifth, and the apex of the unguis
dark brown or black. Third segment of irregular thickness, with eight
circular sensoria arranged in a single row; fourth segment with one sen-
sorium near the apex. Segments three to five imbricated. Length of the
antennal segments as follows: I, .068 mm., II, .041 mm., III, .272 mm., IV,
.163 mm., V, base, .095 mm., unguis, .340 mm. Rostrum light brown, tip
black; reaching to second coxae.
Thorax pale green, lobes olive brown, wing insertions yellowish. Pro-
thorax without lateral tubercles; with several curved hairs much shorter
and finer than those of the head. Wings hyaline. Fore wing with the
media twice-branched, radial sector present, only slightly curved; stigma
hyaline or faintly dusky, veins faint. Hind wing with the oblique veins
very faintly indicated. Legs greenish or slightly dusky, the apices of the
tibiae and the tarsi light brown. Hairs on the legs short, fine, and hya-
line. Length of hind tibia .530 mm.
Abdomen very pale yellowish-green with a few bright green markings.
Hairs of the abdomen hyaline, somewhat longer than those of the thorax.
Cornicles truncate, slightly longer than wide, faintly imbricated; pale
green, somewhat dusky at the apex. Cauda distinctly knobbed, with a few
curved hairs. Anal plate entire, rounded, with several prominent hairs.
Cauda and anal plate green.
Apterous viviparous female. (Plate II, figs. 27-29.) Prevailing color
yellow. Head, thorax, and abdomen all a uniform yellow without markings.
Eyes red. Antennae five-segmented; the first two segments same color as
the head; the third, the basal portion of the fourth, and the basal half of
the unguis, yellowish-brown; the apex of the fourth, the base of the fifth,
and the apex of the unguis, darker brown. Rostrum brown, black-tipped;
reaching to third coxae. Legs a uniform yellowish-brown. Cornicles yellow-
ish-brown, apical portion darker than remainder; length somewhat greater
than the width; surface of the cornicles faintly imbricated. Cauda and
anal plate concolorous with the abdomen; cauda distinctly knobbed, anal
plate entire, almost straight. Hairs on body and appendages hyaline, dusky-
tipped. A study of ten apterous females gave the following measurements:
length of body .707-1.04 mm.; width of head through the eyes .258-.313
mm.; length of antennal segments, III, .122-.163 mm., IV, .082-.109 mm.,
V, base, .068-.082 mm., unguis, .218-.286 mm.; length of hind tibia .299-
.367 mm.
Type locality: Gainesville, Florida.
Types: Holotype alate viviparous female collected from the
leaves of Salix longipes May 16, 1930 (F 460-30), deposited in








THE FLORIDA ENTOMOLOGIST


the U. S. National Museum Collection. Cat. No. 44310. Morpho-
type apterous viviparous female, same data as holotype in the
collection of the author. Paratypes in the collections of the
Entomology Department, Florida Agricultural Experiment Sta-
tion; of A. A. Granovsky, and in that of the author. Types
selected from ten alate females. Type material collected by the
author.
Notes: It is with some hesitation that this species is placed
in the genus Sipha. The species of this genus ordinarily feed
on the leaves of grasses and the fact that this aphid feeds on the
leaves of a woody plant is in itself unusual. However, the five-
segmented character of the antenna, and the form of the cor-
nicles, cauda, and anal plate are quite in agreement with the
characterization of Sipha, so the willow species is provisionally
referred to that genus.
These small, pale green aphids are found thickly clustered on
the undersides of the leaves of willows. The apterous females
are far more numerous than the alate females.
Collections: Salix longipes, Gainesville, May 16, 1930 (F 640-
30) Sept. 18, 1930 (F 703-30), Oct. 8, 1930 (F 717-30) ; Oka-
humpka, Apr. 9, 1932 (F 894-32).

FURTHER NOTES ON THE VELVET BEAN CATERPILLAR
As shown by the writer many years ago (Bul. 130, Fla. Agr.
Exp. Sta.) Anticarsia gemmatilis does not overwinter in north
or central Florida, but the moths fly up each summer from the
south, usually arriving in the Gainesville area in late July or
early August. The insect's inability to overwinter is due to the
fact that it does not hibernate. Though the duration of the pupal
stage is greatly extended in late fall and early winter, the last
moths have always emerged during warm spells in January and,
since their host plants are all very sensitive to frost, they were
unable to raise another generation. But the past winter no kill-
ing frost occurred until March 10, and moths were observed
on March 4 (Fla. Entomologist, XV-No. 4 p. 72). But after the
frost of March 10, when a minimum of 280F. was recorded, no
more moths were seen until June.
As was to be expected after such a mild winter the moths ap-
peared early in July in large numbers and by August 10 some
fields of velvet beans were severely "ragged", soy beans almost
totally stripped of leaves and peanuts severely attacked. This
is the first time that the moths have been observed to lay eggs
on peanuts about Gainesville, although a common occurrence
in the Everglades. On September 9 the caterpillars were found
as far north as Valdosta, Georgia,. but no signs of them were
observed at Tifton, Georgia. J. R. WATSON.








Uhe
FLORIDA ENTOMOLOGIST
Official Organ of The Florida Entomological Society, Gainesville,
Florida.

Vol. XVI SEPTEMBER, 1932 No. 2

J. R. WATSON--....---.... ...----..---.....--------- ...----- -- .....-.--.--.--Editor
E. W. BERGER....---....-....--....-...------ ...... ....... Associate Editor
H. E. BRATLEY.-....--...- ---------.....-..---..--- ...Business Manager
Issued once every three months. Free to all members of the
Society.
Subscription price to non-members is $1.00 per year in ad-
vance; 35 cents per copy.

THE RELATION OF HYDROCYANIC ACID GAS CONCEN-
TRATION AND TEMPERATURE TO THE KILL OF THE
LARVAE IN HIBERNACULA OF THE PECAN LEAF
CASE BEARER, MINEOLA JUGLANDIS (LeB.)
R. J. WILMOT, Special Investigator
Fumigation Experiments, State Plant Board of Florida
FRED W. WALKER, Assistant Entomologist,
Florida Agricultural Experiment Station
INTRODUCTION
One of the pests generally found on pecan nursery stock is the
pecan leaf case bearer, Mineola juglandis (LeB.). While this
insect is not the major nursery pest, it is a pest that can be dis-
tributed from place to place on dormant nursery stock. The win-
ter is passed by this insect in tiny silken cases, called hiber-
nacula. These cases are placed on or behind the buds and when
sufficiently numerous, these insects are capable of almost com-
pletely defoliating the trees when the buds start unfolding in
the spring.
A series of fumigation experiments was conducted to deter-
mine the relation of hydrocyanic acid gas concentration and tem-
perature to the percentage control of this insect. The work was
carried on by the senior author in the fumigation laboratory of
the State Plant Board of Florida. The junior author collected
the infested twigs and made all determinations of the kill after
fumigation.
This is the third of a series of papers dealing with the sub-
ject of the relation of concentration of hydrocyanic acid gas to
kill (2, 3).







THE FLORIDA ENTOMOLOGIST


METHODS
The box of twenty cubic foot capacity previously described
(1), and a California vacuum fumigator were used for this work.
In accordance with all previous work, gas samples were with-
drawn at regular intervals, and analyzed for percent of hydro-
cyanic acid during the duration of the experiment. The Cali-
fornia vacuum fumigator was equipped with sampling tubes, a
thermograph, and a water jacketed burette so that accurate
dosages could be given.
The experiments carried on in the vacuum fumigator were run
at room temperature (520 to 710 F.), with varied dosages, and
those in the twenty cubic foot box at room temperature (510 to
71 F.), and also with the box heated with a thermostatically
controlled heater (910 to 930 F.), with varied dosages and ex-
posures.
The work was done with infested twigs collected at Monti-
cello, Florida. No attempt was made to keep the twigs alive
because under the circumstances they were merely a base for
the attachment of the hibernacula and their life or death had
no effect on the insects. The hibernacula are tough, thick-walled
cases. After fumigation the twigs were shipped back to the
junior author who examined them and determined the kill.
DISCUSSION OF DATA
The data concerning the fumigation of the larvae in hiber-
nacula are found in Table I. In the examination of the table
particular attention should be given to the length of exposure
and temperature during exposure. It will be noted that the lots
are separated into groups, all of which received the same dosage
but had the length of exposure and temperature varied. The
subsequent concentrations and percent control were found to
vary with the temperature and dosage.
It will be noticed that in many cases where the dosage, con-
centration, and length of exposure were the same, the percent
control for the higher temperature would be much higher than
the percent control for the lower temperature.
It will also be noticed that the shortest exposures were not
effective.
SUMMARY
The work here reported shows that a 100% control of the
larvae of the pecan leaf case bearer in hibernacula can be at-
tained only with an exposure of at least 30 minutes to a concen-










VOL. XVI-No. 2 27

TABLE I.-FUMIGATION OF THE LARVAE OF THE PECAN LEAF CASE BEARER.


No. of
Hiber- Dosage
nacula ml. HCN


Lot
No.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17*

18*

19*

20

21

22

23

24

25

26


143

140

105

147

80

135

52

81

117

95

146

124

54

83

127

98

150

84

134

112

121

129

103

65

130

130


*Vacuum fumigator.


3.5

3.5

3.5

3.5

3.5

3.5

3.5

3.5

1.75

1.75

1.75

1.75

1.75

1.75

1.75

1.75

20

10

5

Check

7

7

7

7

7

7


Mean %
Cone. F. % Rel.
HCN Humidity

.3943 92 18

.3862 93 16

.3848 92 13

.3824 93 18


Exposure


15 min.

30 "

45 "

1 hour

15 min.

30 "

45 "

1 hour

15 min.

30 "

45 "

1 hour

15 min.

30

45

1 hour

1 "

1 "

1 "



10 min.

20

30

10 min.

20 "

30 "


54

53

52

52

62

58

58

58

92

92

95

92


.3073

.3294

.3365

.3387

.1792

.1721

.1743

.1796

.2019

.2014

.2011

.1893

.3706

.1857

.1016



.7159

.7529

.7519

.6313

.7204

.7201


80/2

77

76

76

36

36

36


18

15

15

32


28

26

26

75

63

56


71

52

77


91

93

93

61

68

71


Control

99.99

100.00

100.00

100.00

00.00

2.22

3.84

13.58

00.00

00.00

5.47

75.80

22.22

100.00

100.00

100.00

100.00

4.76

90.29



95.04

100.00

100.00

1.53

58.46

100.00









THE FLORIDA ENTOMOLOGIST


tration of .20% HCN or more when the temperature in the fumi-
gation box is held at 900 F. A control of 100% may be attained
in 30 minutes at 710 F. if the concentration is approximately
.72% HCN.
LITERATURE CITED
1. CAMP, A. F. and WILMOT, R. J. Fumigation research in Florida, The
Monthly Bulletin, State Plant Board of Florida, 15 Nos. 5, 6, 7,
8:1-35. 1931.
2. --. The relation of hydrocyanic acid gas concentra-
tion to the kill of various stages of the Blackfly (Aleurocanthus
woglumi Ashby). Jour. Ec. Ent. 25:476-483. 1932.
3. The relation of hydrocyanic acid gas concentra-
tion to the kill of various stages of the Green Scale (Coccus viridis
Green). Jour. Ec. Ent. 25:483-486. 1932.

THE EFFECT OF HYDROCYANIC ACID GAS FUMIGATION
ON THE SUBSEQUENT GROWTH OF
PECAN NURSERY STOCK*
R. J. WILMOT, Special Investigator,
Fumigation Experiments, State Plant Board of Florida
Hydrocyanic acid gas fumigation of nursery stock is required
by many states but its use has been frowned upon by the nurs-
erymen in Florida because they maintained that pecan stock
so treated would not grow off as well as stock treated by scrub-
bing with fish oil soap or other substances to destroy the pests
on it.
An investigation of the literature did not indicate that such
an effect should be expected, so in 1927 an experiment using
480 Stuart pecan trees was started. They were fumigated in 50
cubic foot atmospheric fumigation boxes with forced circula-
tion' with dosages of 7, 10, and 14 cc. of liquid hydrocyanic
acid. Each dosage was run at temperatures of 550-57 F., 750
F, and 950 F. Three lots were also run in a California Vacuum
Fumigator at room temperature with dosages of 10, 20, and 30
cc. of liquid hydrocyanic acid.
The twelve lots of trees were planted in twelve rows on the
Experiment Station farm with checks so interspersed among
them that every fourth tree was a check. The trunk diameter
and lineal growth were recorded until the spring of 1931.

*An abstract of a thesis presented to the University of Florida in June,
1932, as partial fulfillment of the requirements toward the degree of Mas-
ter of Science in Agriculture.
1Camp, A. F. Research work in fumigation. The Monthly Bulletin,
Florida State Plant Board. 12:217-231. 1928.










VOL. XVI-No. 2


TABLE OF DIFFERENCES BETWEEN FUMIGATED TREES
AND CHECKS


1928 |1
I Lineal
A X S Growth
sq. mm. I dm.


-18.91
S12.09
2.21

+ 7.95
9.92
<1


Lot 1
Dif.
P. E.
Odds to 1
Lot 2
Dif.
P. E.
Odds to 1
Lot 3
Dif.
P. E.
Odds to 1
Lot 4
Dif.
P. E.
Odds to 1
Lot 5
Dif.
P. E.
Odds to 1
Lot 6
Dif.
P. E.
Odds to 1
Ei4 -7---
Lot 7
Dif.
P. E.
Odds to 1
Lot 8
Dif.
P. E.
Odds to 1
Lot 9
Dif.
P. E.
Odds to 1
Lot 10


4.77
4.86
<1


+ 0.17
0.42
<1

+ 0.52
0.22
7.28

- 0.30
0.27
1.18

- 1.11
0.80
1.90


- 0.49
0.29
2.57

+ 0.26
+ 0.26
1.00


1929 || 1930 1931
1 Lineal Lineal Lineal
A X S Growth A X S Growth A X S Growth
sq. mm. dm. sq. mm. dm. sq. mm. dm.


-39.97 -0.70 -171.06 -16.24 -343.60 -44.85
16.83 1.62 45.14 5.17 138.31 20.94
7.28 <1 78.37 26.40 8.48 5.38

- 7.60 -0.54 31.86 4.04 95.98 -18.54
14.601 -1.18 65.75- 4.25 96.32 9.00
<1 <1 <1 <1 <1 15.67

18.32 -2.83 -131.85 8.70 -182.06 -22.75
13.13 1.13 65.67 3.71 76.96 17.98
1.63 9.89 5.38 7.28 7.28 1.39

36.51 -2.47 + 0.60 + 1.74 42.25- 2.95
24.50 1.12 71.37 3.79 -109.25 3.79
1.90 6.26 <1 <1 <1 <1

- 4.49 -0.08 + 38.48 3.38- 84.98- 9.25
+12.06 0.96 43.32 3.26 101.13 13.18
<1 <1 <1 1.00 <1 <1


+21.43
12.66
2.571

+59.101
-13.79
215.921


- 2.26
-10.211
<1

+ 8.17
-10.80
<1


13.44 + 0.48 -29.15
6.12 0.30 14.22
5.38 3.57 4.64

3.86 + 1.00 -31.16
5.30 + 0.29 14.79
<1 78.37 5.38


+23.90 +
6.93
44.87


1.59 -16.37
0.65 21.36
8.48 <1


-0.79
-0.98
<1

+1.69
1.04
2.57


-2.02
0.88
6.36


-1.47
0.81
3.45

-2.17
1.25
2.98

-2.63
S1.24
5.38

-3.17
-2.27
1.63


+159.43
- 57.96
13.58

+196.23
+ 55.76
53.951


+112.09
- 45.23
8.48


+ 84.79
+ 42.69
4.00

- 33.34
60.82
<1

-106.31
- 60.22
2.98


- 63.11-
+ 81.33
<1


3.09 +174.83 +19.01
3.47 89.22 11.52
<1 4.00 2.57

8.10 + 98.86 +10.33
3.70 92.33 12.72
5.38 1.00 <1


1.701 +149.60 +21.92
2.34 11 74.95 8.79
<1 | 4.00 8.48


+ 5.51 + 16.17
3.45 75.02
2.21 <1

- 4.75 + 41.69
4.86 86.67
<1 <1

-10.48 35.10
3.89 -+107.53
13.58 <1


10.95
5.45
4.64


- 49.10
163.11
<1
I


+15.62
9.04
2.98

+ 6.13
+12.87
<1

- 1.53
-14.65
<1

- 3.55
18.28
<1


A X S=Area of the cross section of the trunk.


-25.79
8.35
22.26

- 3.51
-- 8.57
<1

- 3.11
6.76
<1

+15.83
- 7.50
5.38


P. E.
Odds to 1
Lot 11
Dif.
P. E.
Odds to 1
Lot 12
Dif.
P. E.
Odds to 1


+:



I


I


1


/









THE FLORIDA ENTOMOLOGIST


Statistical methods applied to the measurements made at
yearly intervals did not indicate that a significant difference in
favor of the checks or the treated trees was obtained under the
conditions of this experiment.
A table of the differences between the checks and the treated
lots follows in which differences in favor of the checks are indi-
cated by a minus sign and those in favor of the treated lots by
a plus sign. Odds of less than 30 to 1 of course are not consid-
ered significant and an examination of the table will show that
after 1928, odds of over 30 to 1 occurred only three times and
then in the cross sectional area of the trunk only, without a sim-
ilar effect on the lineal growth. It will also be noticed that this
difference does not continue through succeeding years.
It can therefore be concluded that under the conditions of
this experiment that fumigation of pecan nursery stock does
not have a detrimental effect on its succeeding growth.

BLISTER-BEETLES ABUNDANT IN FLORIDA
Many of the insects commonly found in Florida have been ex-
ceptionally abundant and troublesome this summer. This situ-
ation is perhaps largely due to the very mild weather of last
winter when most sections of the State experienced a freezing
temperature on only two or three occasions. The blister-beetles
represent one group in which this condition is particularly
noticeable. The striped blister-beetle, Epicauta vittata Fabr.,
has been the most frequent offender and has occasioned the
greatest amount of damage though E. heterodera Horn, the
gray blister-beetle, was concerned in a few instances. Peppers
and eggplant have suffered severely from the attacks of these
beetles, especially in the region surrounding Gainesville. Sweet
potato plantings in the Gulf Hammock section of Levy County
have suffered from the depredations of E. vittata, some fields be-
ing almost completely defoliated. Swarms of these insects have
invaded some of the "ferneries" in Northeastern Marion County
and have severely injured the growing shoots of the Asparagus
plumosus. A. N. TISSOT.


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