A review of laboratory tests on the toxicity of certain semicarbazones to various insects

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Title:
A review of laboratory tests on the toxicity of certain semicarbazones to various insects
Physical Description:
15 p. : ; 27 cm.
Language:
English
Creator:
Gertler, S. I
United States -- Bureau of Entomology and Plant Quarantine
Publisher:
United States Department of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
Place of Publication:
Washington, D.C
Publication Date:

Subjects

Subjects / Keywords:
Biological insecticides -- Testing   ( lcsh )
Insect pests -- Control   ( lcsh )
Genre:
federal government publication   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )

Notes

Bibliography:
Includes bibliographical references (p. 15).
Additional Physical Form:
Also available in electronic format.
Statement of Responsibility:
by S.I. Gertler.
General Note:
Caption title.
General Note:
"E-705."
General Note:
"October 1946."

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 030292603
oclc - 780067997
System ID:
AA00026075:00001

Full Text
LIBRARY
TATE pb rJ3j Z.D- 705
United States Department of Agriculture
Agricultural Research Admiaistration
Bureau of Entomology and Plant Quarantine

A REVIEW OF LABORATORY TESTS ON THE TOXICITY OF CERTAIN
SEZYIC&BAZONES TO VARIOUS INSECTS

By S. I. Gertler, Division of Insecticide Investigations


In the course of its investigations the Division of Insecticide Investi-
gations prepared a large number of semicarbazones and submitted them to other
Divisions of the Bureau for laboratory tests against a number of insects. Some
of these compounds seemed to be promising. Four patents have been granted on
this class of cemnounds (1, h, 5, 6). It was therefore considered advisable to
compile tli, results of the tests in such a manner as to facilitate the selec-
tion of the compounds that were most toxic to any given insect and also those
that were toxic to a number of different insects.

Semicarbazones may be prepared by condensing aldehydes and ketones with
semicarbazide under suitable conditions. Most of them are colorless solids,
which crystallize well and have physical properties that easily lend themselves
to the preparation of insecticidal mixtures.
The Insects tested and the Divisions in which they were tested are as
follows:

Division of Cereal and Forage Insect Investigations:

Ruropean corn borer (Pyrausta nubilalis (Cbn,))

Division of Control Investigations:

American cockroach (Periplaneta americana (L.))
Bean leaf roller (Urbanus proteus (L.)TF
Three-striped blister beetle (Epicauta lemmniscata (F.))
Cabbage looper (Trichoplusia ni (Hbn.)) (=Autographa brassicae (Riley))
Cowpea weevil (Callosobruchus maculatus (F.)) (=C. chinensis (L.))
Cross-striped cabbageworm (Evergestis rimosalis TGuei)
Hawaiian beet webworm (Hymenia recurvalis (F.)) (=Z_. fascialis (Cram.))
Imported cabbageworm (Pieris raiae (L.))
A looper (Pseudoplusia rugationis (Guen.)) (=Autonapha o0o (Stoll))
Melonworm (Diaphania hyalinata (L.))
Mexican bean beetle (Epilachna varivestis Muls.)
Okra caterpillar (Anomis erosa iHbnn.T
Rice weevil (Sitophilus oryza (L.))
Southern armyworm (Prodenia eridania (Cram.))
Squash bug (Anasa tristis (Deg.))
A termite (Reticulitermes flavipes (Z.))
Yellow woollybear (Diacrlsia virginica (F.))

Division of Fruit Insect Investigations:

Codling moth (Carpocapsa pomonella (L.))


OCT 2 4 1940




-2-


Division of Insects Affecting Man and Animals:

Furniture carpet beetle (Anthrenus vorax (Waterh.))
Mosouito (larvae) (OCulex cuinouefasciatus Say)
Screwworm (Cochllomyia americana C. and P.)

The methods used for testing are the usual standardized ones which have
been used in the past, and so are mentioned only briefly. All the compounds
tested against each insect are listed in order of toxicity. Compounds that
were tested both as a dust and as a spray are listed twice. All dosages are
for dusts. When no figure is given in the dosage column, the material was
applied as a spray at a concentration of 8 pounds per 100 gallons unless in-
dicated otherwise.

American Cockroach (10)

Cockroaches that were three-ouarters grown were confined for 2 days in
a jar on the bottom of which 0.25 gram of the compound had been dusted. The
following compounds were tested: Semlcarbazones of benzophenone, r-chloro-
acetophenone, o-chlorobenzaldehyde, cyclohexanone, cyclopentanone, 2,6-di-
methyl-h-heptanone, 2,4-dimethyl-3-pentanone, 2-furaldehyde, levulinic acid,
2-methylcyclohexanone, methyl ethyl ketone, piperonal, vanillin, and o-veratval-
dehyde. None of these compounds showed any toxicity to the roaches.


Bean Leaf Roller

This-test was carried out by feeding dusted bean leaves to fifth instars.
The- only compound tested was cyclohexanone semicarbazone in a dosage of 355
micrograms per souare centimeter. It gave 87 percent kill in 3 days.


Three-Striped Blister Beetle

The adult beetles were fed either dusted or sprayed swiss chard leaves.


Semi carbazone Dosage Days Percent
(micrograms per exposed kill
square centimeter)

4-Methylcyclohexanone 230 2 100
100
Zthyl methyl ketone 250 2 100
6 100
2, 4-Dimethyl-3-pentanone 6 97
280 2 96
2-Methyl cyclohexanone 200 2 95
Cyclohexanone 200 2 90
2-Chloroacetophenone 6 87
Cyclopentanone 215 2 85
2-Furaldehyde 8 77
Cyclohexanone -6 76
Benzophenone 285 3 29
D-Chloroacetophenone 280 2 0
7-Flraldehyde 185 2 0





-3-


Three-Striped Blister Beetle--cont.

Semicarbazone Dosage Days Percent
(micrograms per exposed kill
square centimeter)

2-Methyl cyclohexanone 6 0
Salicylaldehyde 150 2 0
o-Veratraldehyde 260 2 0


Cabbage Looper

This test was conducted by feeding fifth instars dusted collard leaves.
The only compound tested was p-chloroacetophenone semicarbazorne, which at a
dosage of 280 micrograms per square centimeter gave 4 percent kill in 2 days.


Codling Moth (9)

These tests were conducted on newly hatched larvae, by the apple-plug
method, infested shortly after application. M-ich compound was sprayed at
a concentration of 4 pounds per 100 gallons.


Semicarbazone Percent Percent
wormy stung

2-Chloroacetophenone 7 21
2-Octanone 17 2
Cyclopentanone 21 0
2-Heptanone 30 0
2-Fuzaldehyde 35 21
4-Methylcyclohexanone 39 0
2-Methylcyclohexanone 42 0
Cyclohexanone 50 1
2,4-Dimethyl-3-pentanone 53 0
Ethyl methyl ketone 56 7
Cinnamal dehyde 66 0
Methyl propyl ketone 67 3
Sali cylaldehyde 74 0
Benzophenone 76 0
4-Methyl-2-pentanone 76 0
o-Veratraldehyde 77 0
L-Hydroxyacetophenone 78 0
Acetoacetic acid, ethyl ester 79 3
alpha-Ethylbutyraldehyde 79 1
o-Chlorobenzaldehyde 02 0
p-Methylacetophenone 82 0
Crotonaldehyde 84 0
r-Aminobenzophenone s6 0
Benzoin 86 1
Levulinic acid 86 0
2,6-Dimethyl-4-heptanone 87 0







Codling Moth-cont.

Semicarbazone Percent Percent
wormy stung

Acetophenone 98 0
Vanillin 8g 0
Benzaldehyde 90 2
Piperonal 91 0
3,4-Dichloroacetophenone 92 2
Benzil (mono) 93 0
Acetonylacetone (di) 95 0


Cowpea Weevil

Adult weevils were exposed in a petri dish with peas sprayed with the
compound at a concentration of 1:1000.


Semicarbazone Days exposed Percent kill

Methyl ethyl ketone 5 Sg
Methyl propyl ketone 5 79
Levulinic acid. 4 77
Qyclopentanone 5 70
2,6-Dimethyl-4-heptanone 5 60
14-Methyl-2-pentanone 5 52
Salicylaldehyde 5 41
Cyclohexanone 4 33
Benzoin 4 26
2,4-Dimethyl-3-pentanone 4 22
3,4-Dichloroacetophenone 4 20
Benzophenone 4 19
2-Heptanone 4 14
Piperonal 4 7
Acetoacetic acid, ethyl ester 4 4
k-Chloroacetophenone 4 4
o-Mhlorobenzaldehyde 4 4
2-Aminobenzophenone 4 3
Benzil (aono) 4 3
Aeetophenone 4 0
2-Tural dehyde 4 0
Vanillin 4 0


Cross-striped Cabbageworm


Insects of the fifth instar were fed dusted collard leaves.





-5-


Dosage Days Percent
Semicarbazone (micrograms per exposed kill
square centimeter)

Cyclohexanone 310 2 100
Cyclopentanone 200 3 100
Ethyl methyl ketone 290 2 100
2-Methylcyclohexanone 140 3 100
S6 100
4-Methylcyclohexanone 3-5 2 100
4100
Cyclohexanone 4 97
Cyclop 'ntanone 6 65
2-Pura- Jdehyde 165 3 37
2-Heptanone 435 3 23
2,4-Dimethyl-3-pentanone 150 3 13
Levulinic acid 420 2 7
2-Aminobenzophenone 340 3 0
Benzil (mono) 210 3 0
o- Chl'orobenzaldehyde 270 2 0
3,4-Dicbloroacetophenone 185 3 0
Piperonal 155 2 0

hropean Corn Borer (5)

Newly hatched larvae were fed. sprayed. cauliflower leaves. For the sake
of comparison all results will be given at a concentration of 4 pounds per
100 gallons although further tests were made at a concentration as low as 1
pound per 100 gallons.


Semicarbazone Days exposed. Percent kill

Acetophenone 3 99
Benzaldehyde 3 94
2,6-Dimethyl--heptanone 3 94
k-Chloroacetophenone 2 91
p4Methylacetophenone 3 76
Ethyl methyl ketone 3 11
Benzophenone 3
Cyclopentanone 3 6
4-Methyl-2-pentanone 3 3
Methyl propyl ketone 3 3
Piperonal 2 3
Salicyladehyde 3 3
Acetoacetic acid, ethyl ester 2 2
Acetonylacetone (di) 3 2
p-Aminoben z ophenone 2 2
o-Chlorobenzaldehyde 2 2
Crotonaldehyde 3 2
3 ,4-Dichloroacetophenone 2 2
2,4-Dimethyl-3-pentanone 2 2
i-Heptanone 2 2
-Methylcyclohexanone 2 2





-6-
European Corn Borer-cont.

Semicarbazone Days exposed Percent kill

2-Octanone 3 2
Vanillin 2 2
B-Aminobenzophenone 2 1
Benzil (mono) 2 1
Cyclohexanone 2 1
4-Methylcyclohexanone 2 1
o-Veratrald.ehyde 2 1
gipha-Ethylbutyraldehyde 2 0
Levulinic acid 2 0


Furniture Carpet Beetle (2)

The insects used were half-grown larvae. The results are given in
terms of the ratio of the mortality produced by sodium fluosilicate solution
to that produced by the compound.


Semicarbazone


Mortality
ratio


Semicarbazone


Mortality
ratio


2-Aminobenzophenone
2-Ghloroacetophenone
Benzophenone
Cyclohexanone
Benzil (mono)
Acetophenone
3,4-Dichloroacetophenone
Benzaldehyde
Methyl propyl ketone
2-Furaldehyde
2-Heptanone
2,6-Dimethyl-4-heptanone
2,4-Dimethyl-3-pentanone


1.4
1.4
1.5
2.7
3.6
4.1
4.2
4.6
5.0
6.5
7.0
7.3
7T. 4


Crotonaldehyde
o-Chlorobenzaldehyde
Ethyl methyl ketone
Acetoacetic acid, ethyl
ester
Piperonal
Cyclopentanone
R-Methylacetophenone
Vanillin
alpha-Ethylbutyraldehyde
Acetonylacetone (di)
2-Octanone
4-Methyl-2-pentanone
Salicylaldehyde


Hawaiian Beet Vebworm (10)

The test insect was the fifth instar, which was fed dusted Swiss chard
leaves.

Dosage Days Percent
Semicarbazone (microgram per exposed kill
square centimeter)


p-Chloroacetophenone
Cyclohexanone

Cyclopentanone
2-Methylcyclohexanone
4-Methylcyclohexanone


240


100
100
100
100
100
100


8.0
10.4
10.6

10.7
11o0
12.3
12.7
1,5.0

18.2
19*21
19.1
21.5
21.5





-7-


Hawaiian Beet Webworm-cont.

Semicarbazone Dosage Days Percent
(micrograms per exposed kill
square centimeter)

r-COhloroacetophenone 355 3 96
Cyclopentanone 325 2 96
Ethyl methyl ketone 395 2 96
2-Reptanone 250 2 96
2, 4-Dimethyl-3-pentanonfe 6 94
2-Furaldehyde -4 94
2,4-Dimethyl-3-pentanone 280 3 55
2-2Furaldehyde 395 2 88
2-Hepta, one 6 82
Z-Aminobenzophenone oo00 3 77
Salicylaldehyd.e 495 2 76
2,6-Dimethyl-4-heptanone 195 2 64
Methyl propyl ketone 280 2 48
Benzil (mono) 195 2 45
Benzophenone 340 2 40
Acetophenone 465 2 28
Crotonaldehyde 200 2 28
Acetoacetic acid, ethyl ester 215 2 12
3,4l-Dichloroacetophenone 155 2 12
Benzaldehyde 185 2 8
alpha-Ethylbutyraldehyde 280 3 5
p-Hydroxyacetophenone 435 2 8
Sal i cylaldehyde 495 2 8
Benzoin 310 2 4
-Methylacetophenone 355 2 4
li-Methyl-2-pentanone 185 2 4
Acetonylacetone (di) 170 2 0
Cinnamal dehyde 185 2 0
Piperonal 200 2 0

Imported Cabbageworm (10)

Tifth-lnstar larvae were fed dusted collard leaves for 2 days.


Dosage Percent
Semicarbazone (micrograms per kill
square centimeter)

2-Furaldehyde 385 96
Benzophenone 340 72
2,6-Dimethyl-4-heptanone 155 72
Acetophenone h65 44
Cyclopentanone 325 32
alpha-Ethylbutyraldehyde 280 30
Cinnamaldehyde 155 23
Benzaldehyde 185 16
Ethyl methyl ketone 3585 16





- 9 -.


Imported Cabbageworm-cont.

Semicarbazone Dosage Percent
(micrograms per kill
square centimeter)

Salicylaldehyde 495 16
Acetonylacetone (dli) 170 12
Or o tonal dehyde 200 12
?-Hydroxyacetophenone 435 12
-Methyl-2-pentanone 185 12
2-Chloroacetophenone 280 8
1-Methylacetophenone 355 0
Methyl propyl ketone 280 0
2-Octanone 185 0

Looper

Fourth instars were fed sprayed collard plants.

Semicarbazone Days exposed Percent kill

2-HeDtanone 6 67
Ethyl methyl ketone 6 514

Melonworm (10)

Fourth instars were fed dusted or sprayed pumpkin leaves.

Semi carbazone Dosage Days Percent
(micrograms per exposed kill
square centimeter)

Cyclohexanone 355 3 100
2,4-Dimethyl-3-pentanonel/ i 100
2-Furaldehye.e 4 100
Cyclopentanone 2 96
2,14-Dimethyl-3-pentanone 230 3 92
4-Methylcyclohexanone 356 3 87
p- Ohloroacetophenonej/ 7 79
287 3 78
2-Methyl cyclohexanone 6 7
p-Am nobenzophenone 370 3 72
2-F irIdeyde 435 2 72
Piperonal 230 72
4-Methyl cyclohexanone 52
2-Methylcyclohexanone 385 3 44
2-Heptanone 280 3 34

1/ Concentration 4 pounds per 100 gallons.





-9-
Melonworm--cont.

Semicarbazone Dosage Days Percent
(micrograms per exposed kill
square centimeter)

Acetoacetic acid, ethyl ester 217 3 24
Oyclopentanone 325 2 24
Ethyl methyl ketone 385 2 24
Levulinic acid 450 2 16
Salicylaldehyde 230 2 12
Acetonylacetone (di) 215 2
alpha-Ethylbutyraldehyde 190 3 8
Crotonaldehyde 200 2 4
2,6-Dimethyl-4-heptanone 185 2 4
Methyl propyl ketone 280 2 4
Vanillin 230 2 4
Cyclohexanone 6 3
Ethyl methyl ketone 2 3
Acetophenone 340 2 0
Benzaldehyde 155 2 0
Benzll (mono) 170 2 0
Benzoin 355 2 0
Benzophenone 420 2 0
o-Chlorobenzaldehyde 495 2 0
Cinnamaldehyd.e 125 2 0
3,4-Dichloroacetophenone 155 2 0
p-Hydroxyacetophenone 250 2 0
2-Methylacetophenone 355 2 0
4-Methyl-2-pentanone 185 2 0
2-Octanone 185 2 0
o-Veratral dehydle 310 2 0

Mexican Bean Beetle (1)

Tests were conducted on fourth instars by the spray-tower petri-dish
technique. A suspension of the compound in water containing 0.1 percent
of acacia was used. Insects were exposed for 6 days.


Semicarbazone Percent Percent
concentration kill

Ethyl methyl ketone 0.5 95
Oyclohexanone 1.0 92
Oyclopentanone 1.0 60
2-Furaldehyde 1.0 55
2, 4-Dimethyl-3-pentanone 1.0 57

Mosquito Larvae ()

Tests were conducted on fourth instars by the standard laboratory method.
The concentration was 100 parts per million in all cpses, and the erxoosure
time was LO hours except for alpha-ethylbutiraldehyde, when it was 16 hours.
LIBRARY
STATE PLANT BOARD





- 10-


Semicarbazone Percent Semicarbazone Percent
kill kill

alpha.-Ethylbutyraldehyde 100 p-Hydroxyacetophenone 3
Salicylaldehyde 50 Acetonylacetone(di) 0
2,6-Dimethyl-4-hep tanone 18 Benzaldeande 0
Cinnamaldehyde 7 Orotonaldehyde 0
p-Methylacetophenone 4

Okra Caterpillar

Three-fourths grown insects were fed dusted okra leaves. Insects
were exposed 5 days.


Semicarbazone Dosage Percent
(micrograms per kill
square centimeter)

p-Chl oroacetophenone 400 100
2,h-Din:ethyl-3-pentanone 285 100
b'Methylcyclohexanone 210 93

Rice Weevil

Adult insects were fed wheat sprayed with the compound at a concentra-
tion of 1:1000.


Semicarbazone Days exposed Percent kill


Methyl propyl ketone 5 30
Ethyl mTethyl ketone 5 25
Levulinic acid 4 9
Cyclohexanone 4 5
p-Chloroacetophenone 4 4
2,4-Dimethyl-3-pentanone 4 4
pD-Ami riobenzophenone 2 3
Cyclopentanone 5 3
2-Furaldehyde 4 3
2-Heptanone 4 3
h-Methyl-2-pentanone 5 3
Acetoacetic acid, ethyl ester 4 2
?enil (mono) 4 2
Acetophenone 4 0
Benzoin 4 0
Eenzonhenone 4 0
o-Ch crobenzaldehyde 4 0
, -Dichloroacetophenone )1 0
2,6-Dimethyl-h-heptanone 5 0
Piiercnal 4 0
Sa i cylldehyde 5 0
Vanill in 0





- 11 -


Screwworm (7)

The jar method, was used on newly hatched larvae.


Semicarbazone
Minimum lethal concentration
(Percent)


Benzophenone
2,6-Dimethyl-L-heptanone
Acetophenone
Crotonaliehyde
Gyclohexanone
2, -Dimetl -'-3-pentanone
2-PFuraldehyde
Cyclopentenone
Ethyl methyl ketone
2-THetanone
Levulinic acid
2-Methylcy clohexanone
4-Methylcyclohexanone
Methyl propyl ketone
4-Methyl-2-pentanone
alpha-Ethylbutyraldehyde
Acetoacetic acid ethyl ester
Acetonylacetone (di)
Benzaldehyde
2-Octanone
p-Am inobenz oophenone
Benzil (mono)
Benzoin
_-Chloroacetophenone
-Chlorobenzaldehyde
Cinnamaldehyde
3,L-Di chloroacetophenone
i-Methylacetophencne
Piperonal
Salicylaldehyde
Vanillin
o-Veratraldehyde


0.01 0.025


0.05 0.01





o.oi 0.166



0.166 0.34
o.34 o.666

Slightly toxic at 0.666







Nontoxic at 0.666


.


Southern Armyworm

Fourth instars were fed dusted or sprayed collard. leaves,

Semicarbazone Dosage Days Percent
(micrograms per exposed kill
square centimeter)


2,4-Dimethyl-3-pentanone

2-Methylcyclohexanone
4-yethyl cyclohexanone
?-Methyl cyclohexpione


195

385
356


100
100
100
100
97






Southern Armyworm--cont.


- 12 -


Semicarbazone Dosage Dnys Percent
(micrograms per exposed kill
square centimeter)
4-Methylcyclohexanonel/(See page 8.) 5 91
p-Chloroacetophenone 385 2 33
Cyclohexanone 4 30
Ethyl methyl ketone 4 19
Oyclopentanone 6 9
2-Chloroacetophenone 4
Cyclopentanone 345 2 7
2-Furaldehyde 4 4
Acetoacetic acid. ethyl ester 213 2 0
Acetonylace tone (dl) 230 2 0
Acetop-e-.. ,e 503 2 0
2-Aminobenzophenone 400 2 0
Benzaldehyde 225 2 0
Benzil (mono) 185 2 0
Benzoin 510 2 0
Benzophenone 500 2 0
o-Chlorobenzaldehyde 250 2 0
Cinnamaldehyde 240 2 0
Cyclohexanone 240 2 0
3,4-Dichloroacetophenone 155 2 0
2,6-Dimethyl-4-heptanone 195 2 0
alpha-Ethylbutyraldehyde 265 2 0
Ethyl methyl ketone 535 2 0
2-F'uraldehyde 510 2 0
2-Heptanone 280 2 0
2-Hydroxyacetophenone 365 2 0
"-Methyl-2-pentanone 250 2 0
Methyl propyl ketone 395 2 0
2-Octanone 230 2 0
Piperonal 230 2 0
Sali cylaldehyle 580 2 0
Vanillin 355 2 0
o-Veratraldehyde 24O 3 0
Trot onaldehyde 155 2 0

Squash Bug

Second instars were dusted directly and fed untreated pumpkin leaves.


Semi carbaz one Dosage Days Percent
(micrograms per exposed kill
square centimeter)

Cyclohexanone 425 1 4
p- Chloroacetophenone 355 2 0
2,4-Dimethyl-3-pentanone 310 2 0
Ethyl methyl ketone 44o 2 0
2-Furaldehyde 525 2 0





- 13 -


Termites

Adult insects were placed on treated soil. All results are given at
a concentration of 1:1000.


Semicarbazone Days exposed Percent kill

2-Octanone 2 100
p-Chloroacetophenone 4 52
Benzophenone 4 45
Hydroxyacetophenone 3 29
Methyl-2-pentanone 26
2, 4-Dimethyl-3-pentanone 24
2-Methyl-yclohexanone 1 13 (1:5000)
Cyclohexanone 2 1i
Ethyl methyl ketone 3 9
o-Veratraldehyde 3
Acetonylacetone (di) 3 0
Acetophenone 3 0
Benzaldehyde 3 0
Benzoin 3 0
Orotonaldehyde 3 0
Cyclopentanone 3 0
2,6-Dimethyl-4-heptanone 3 0
alpha-Ethylbutyraldehyc e 3 0
2-Furaldehyde 4 0
2-Heptanone 4 0
p-Methylacetophenone 3 0
Methyl propyl ketone 3 0
Salicylaldehyde 3 0

Yellow Woollybear

Benzophenone semicarbazone was the only compound tested against this
insect. Fourth instars were fed dusted collard leaves at a dosage of 335
micrograms per square centimeter and gave a 44 percent kill after 3 days'
exposure.

Summary of Results

All compounds were considered toxic to leaf-eating insects if they
gave at least 75 percent kill. In the case of the codling moth, those
that gave less than 50 percent of wormy fruit were included. For the
screwworm all compounds having a minimum lethal concentration of 0.1 per-
cent were chosen. Other results were selected on a similar basis.

The following list includes all semicarbazones that were definitely
toxic to one or more insects and the number of species to which each was
toxic:








Semicarbazone Number of Semicarbazone Number of
species species

Cyclohexanone a 2,6-Dimethyl-4-heptanone 2
4-Methylcyclohexanone g Levulinic acid 2
p-Chloroacetophenone 7 Methyl propyl ketone 2
Cyclopentanone 6 2-Octanone 2
2,4-Dimethyl-3-pentanone 6 2-Aminobenzophenone 1
Ethyl methyl ketone 6 Benzaldehyde 1
2-Furaldehyde 6 Crotonaldehyde 1
2-Methylcyclohexanone 6 alpha-Ethylbutyraldehyde 1
2-Heptanone 3 2-Methylacetophenone 1
Acetophenone 2 Salicylaldehyde 1
Benzophenone 2

It is noteworthy that, of the 33 semicarbazones tested, 21 shoved defi-
nite toxicity to 1 or more insects. Of the 8 most toxic compounds 4 are
semicarbazones of cyclic aliphatic ketones, and they were the only compounds
of this group which were tested.. Aside from these, no particular group stands
out. However, there seem to be some differences in toxicity exhibited by
small differences in composition in some groups. For example, of 7 semicar-
bazones of ketones containing an aromatic group, o-chloroacetophenone semicar-
bazone was found to be the most effective, 3,"-Dichloroacetophenone semicar-
bazone was entirely ineffective, and other substituted acetophenone and.
benzophenone semicarbazones were not so toxic as acetophenone and benzo-
phenone themselves,

Of 7 aliphatic ketone semicarbazones, 5 showed some toxicity, and 2 of
these,.2,4-dimethyl-3-pentanone semicarbazone and ethyl methyl ketone semicar-
bazone, were among the most effective materials tested.

In general, it may be concluded that semicarbazones as a group show
promise as insecticides against selected insects.







Literature Cited


(1) Bushland, R. C., and King, W. V. 1943. Laboratory tests with
organic compounds as larvicides for Culex Quinquefasciatus
Say. U. S. Bur. Ent. and Plant *uar. E-585, 15 pp. (Pro-
cessed.)

(2) Colman, W. 1943. Tests of chemical compounds against fabric
insects. U. S. Bur. Ent. and Plant Quar. E-592, 12 pp.
(Processed.)

(3) Gertler, S. I., and Haller, H. L. Insecticide. U. S. Patent
2,261,735, issued Nov. 11, 1941.

(4) ------------- and Hailer, H. L. Insecticide. U. S. Patent
2,374,479, issued April 29, 1945.

(5) -----------and Haller, H. L. Insecticide. U. S. Patent
2,408i,307, issued Sept. 24, 1946.

(6) Haller, H. L. Insecticide. U. S. Patent 2,292,756, issued
Aug. 11, 1942.

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