Laboratory and field tests of toxicity of some organic compounds to the European corn borer

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Title:
Laboratory and field tests of toxicity of some organic compounds to the European corn borer
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English
Creator:
Questel, D. D ( David Dewitt ), 1899-
United States -- Bureau of Entomology and Plant Quarantine
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U.S. Department of Agriculture, Bureau of Entomology and Plant Quarantine Washington, D.C )
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U.S.
\DEPARTMENT
OF
AGRICULTURE
BUREAU OF
ENTOMOLOGY AND
rLANT QUARANTINE


LABORATORY AND FIELD TESTS OF TOXICITY OF SOME ORGANIC COMPOUNDS TO

THE EUROPEAN CORN BORER



Ey D. D. Questel. Division of Cereal and Forage insect Investigations, and
S. I. Gertler, L. E. Smith, and D. L. Vivian, Division of Insecticide
Investigations/


1/ A few of the compounds reported upon were prepared by W. G. Rose,
M. S. Schechter, and C. V. Bowen of the Division of Insecticide Investi-
gations.


CONTENTS


Page
Introduction ................1
Laboratory tests .......... 2
Methods ....................... 2
Results ........................ 3
Discussion ................ 14


Page
Field tests .............. ... 14
Methods .............. 14
Results ............ 15
Discussion .............. 17


INTRODUCTION

Laboratory investigations of organic compounds to establish their
toxicities to newly hatched European corn borer larvae were begun at Toledo,
Chio, early in 1938 and continued in 1939 and 1940. Field tests with some
cf the more promising of these compounds were conducted at the U. S. Depart-
rent of Agriculture Experimental Farm southwest of Toledo in 1939 and 1940.
All the compounds were supplied by the Division of Insecticide Investiga-
tions, and the laboratory and field tests vere made by the Division of
Cereal and Forage Insect Investigations,


December 1941


E-557







-2-


LABORATORY TESTS

Methods

As insecticidal control of the corn borer is directed at the young
larvae, it having been found extremely difficult to poison the larvae in
their later instars, newly hatched larvae were utilized in all laboratory
tests reported herein.

The larvae used in the tests were obtained from eggs laid by moths
reared in the laboratory from field-collected borers. Usually the borers
were retained in cold storage for several months in order to satisfy their
diapause requirements and thus provide a continuous supply of moths as
needed. Male and female moths were confined in a cylindrical, wire (5 meshes
to the inch) oviposition cage 1 foot high and 9 inches in diameter. The
side wall of the cage was covered on the outside with coarse cheesecloth,
which is not a suitable surface for oviposition, to prevent the escape of
the moths from the cage. The top of the cage, which was also of coarse-
mesh wire, was covered with a sheet of waxed paper, and the moths readily
oviposited on this surface through the wire mesh. The cage was placed
under a bell jar to insure the high humidity that is favorable to oviposition.

The paper with the attached egg masses was removed daily, and the
sheet out into small sections, each containing an egg mass. These masses
were -1hen placed in a gallon earthenware jar containing moist blotting paper
and allowed to incubate. From 20 to 100 egg masses in the "blackhead stage"
were required daily when the chemicals were being tested.

Green beet leaves treated with the material under test were used as
the feeding medium in early tests. However, extensive decay and disintegra-
tion of these leaves contributed to high mortalities among the newly hatched
borer- confined with them. For this reason cauliflower leaves, which do
not decompose so readily as beet leaves, and upon which the borer thrives,
were substituted for the beet leaves in the later tests. This change
resulted in lower mortalities both on untreated leaves and on leaves that
had been treated with a nontoxic material.

The borers were retained under observation for '12 or 96 hours in the
early tests. This period later was reduced to 48 hours because it is
advantageous in corn borer control to secure a rapid kill. Otherwise the
rapid growth of the corn plant tends to expose new, untreated growth at the
feeding areas, thus reducing the feeding period on treated surfaces and
perhaps allowing the borer to recover by feeding upon the untreated portions
of the plant.

The sprays were prepared by grinding with a stirring rod 0.25 g. of
the compound in a beaker containing a little water plus all the wetting
agent, sodium monosulfonate of butylphenylphenol (Areskap), required to
furnish a dilution at the rate of 1 g, of wetting agent to 2,000 cc. of







-3-


water 'n the completed spray. After the. material had been finely ground,
enough water was added tto bring Lhe di1ution of the compound to the rate
desired.

This preparation was sprayedJ Ihoroughiy upon fresh green leaves
with a small atomiz i 7Or to an air-pressure tank fitted with a
low-capacity automatic airs -,tu~ar sA for 1.0 pounds' pressure. As soon
as the surface water iacd ; aporatcd 'rom the; caves they ,riere made, into a
small roll and inserted into a test tuLe containing one or two corn borer
egg masses in the "blackhead stage," which just precedes hatching, A cotton-
filled cloth stopper was used to plug the mouth of the tube (fig. 1).

OQservations were nma0- ,a l -i, cnd, on completion of tbe test period.
rGncords wore made of t dca-l lin h ng larvee, [he condition of 1he leaves.
and the amount of feeding that had occurred (fig. 2).

Materials first were testeCd at the rate of 4 pounce per 100 gallons
of water. Those materials that gav. high mortality with little or no
feeding were retested at either 2 pounds or 1 pound per 100 gallons of
water, or both.

Results

A11 the materials tested in the laboratory and the mortality for
each are given in tables 1, 2, and 3.
The compounds reported on have been arranged in groups. This classi-
fication is purely arbitrary, as scr> of the. materials could be placed in
any one of several groups, but as this system has becn used in recording
tests of synthetic organic compounds against other insects, it is used in
reporting this work.






4 -

Table I.. -euts of laboratoryy tests of some organic compounds used as insecticides againstnewly
hatched European corn borer larvae at a dilution of 4 pounds to 100 gallon of water I_/



ACIDS, ALCOHOLS, AND ESTERS


Compounds


E1204 Benzohydroi

E1569 3,4-Iðyleneoxybenzal-p-amino
benzoic acid

E131 4,6-Dinitro-o-cresol acetate

E1537 2,4-Dinitrophenol acetate

E42 9-Fluorenol


E1195 Ethyl ester of 4-acetyl-3-
..ydr xy-2-naphthoic acid

E379 Diphenyl ester of carbonic acid

E1570 3-Methoxy-4-hydroxybenzal-p-
aminobenzoic acid


E2211 Benzoyi peroxide


Number
of larvae
used in
treatment 2/


C5H*1N04

C 9H 8NzO G


CBHcN2Oc

C13HoO



C,5H1404

C13HI003



C1sH13N04

C14H1004


133



307

64

198

70



130

128



127

163


Average
percent
mortality
Not
Treated treated

94.6 3.2


91.2

89.0

80.3

17.1



12.2

7.1



4.7

0.6


2.3

2.0

4.8


2.0



4.9

3.2



0.9

1.7


AZO, HYDRAZO, AND RELATED COMPOUNDS


p-Iodoazobenzene C12H9IN2 30 100.0 2.0 0

p-Bromoazobenzene CizHgBrN2 79 100.0 2.0 0


p-Bromoiyd razobenzene C,2H*iBrNz 217 99.1 4.9 0 + (a)

I/ Are~kap was used as the wetting age.,t at tho rate of 1 gram in 2,000 cc. of water.


!/ Appr-xiwateiy the same numbers of larvae were used in the nontreated tests.

,3/ oi. denot extent of feeding as follcv;4: 0 -none, + little, ++ moderate,
munh. The period of tests was 48 ,ours ex-ept as indicated, the letter (a) denot-
ing a 72-hotr tes.t period and the letter (b) denoting a 96-hour period.


Amount
of
feeding 3/


o + (a)


0-

0-


++ (a)

+

++


E96

E263

E1207








-5-


Table 1. -- Continued


0, HYDRAZO, I


Compound


Cod
No.


-E248 Azokybenzene

E1i67 pp'-Diiodoazoxybenzene

E1514 1-0-Tolyiazo-2-naphthylamine

E1168 pp'-Azobis-(beazoiQ acid)

E1171 pp'-Azobisbiphenyl

E1170 pp'-Hydrazobisbiphenyi

E1171 pp'-Azobisphenol.

E1173 ppl-Azobisphenetole

E126 1-Phenylazo-2-naphthylamine

E1513 1-Xylylazo-2-naphthol

E1516 alpha-(o-Nitro-p-anisylazo)



E1513 1-Xylylazoxylazo-2-naphthol

E1519 1-(o-Nitro-p-tolylazo)-2-naphthol

E453 1-(p-Phenylazophenylazo)
-2-naphthol

E1321 1-(o-Tolylazo)-2-naphthol

E1520 1-(2,4-Dinitrophenylazo)
-2-naphthol

Ei16 alpha-(o-Nitro-p-tolylazo)
acetoavetanilide

E1518 i-(u-Chloro-p-nitrophenylazo)
-2-naphthol


110

179

132


ND RELATED COMPOUNDS

Number
of larvae
used in
treatment



C12HioN20 108

C12a8I2N20 204

C17HsN3 117

C141ioN204 138

C24HiN2 124

C24H2oN 126

012H1oN202 126

C16{18N202 102

C16HI3N3 113

C18Hi6N20 127


4.0

2.9

2.7


2.4

2.4



2.2


119


2.1

2.1

2.1


2.1

2.1



2.1



2.1


+4+


++ (a)



+++ (a)


1.1 2.1 f++ (a)


(Continued)

Average Amount
percent of
mortality__ feeding 3/
2/ Not
Treated treated


98.2 8.3 + (a)

36.6 10.7 ++ (a)

29.6 2.1 ++ (a)

26.5 10.7 ++ (a)

16.9 10.7 +++ (a)

16.4 10.7 +++ (a)


12.1 10.7 +++ (a)

11.7 10.7 +++ (a)

9.6 2.1 +++ (a)

4.9 2.1 +++ (a)


C1sH ilN405

C26H24N40

C171H 13N303



C2 2H16N40

C17H14N20



C16HjoN405



C17HIsN404


C16HloClN30)3 141







-6-


Table 1. -- Continued


ALDEHYDES AND KETONES


Compounds


1,5-Diphenyl-3-pentadienone

3,4-Dichloroaoetophenone

Dibenzaltriacetophenone (Isomer B)

Benzaldiacetophenone

Dianisal cyclopentanone

Dipiperonal cyclopentanone

Anisalacetophenone

2-Hydroxybenzaldiacetophenone

9-Fluorenone

p,omega-Dichloroacetophenone


Number
of larvae
used in
treatment 2/


C17H140

CaH6C12O

C3H3203


C23H2o03

C21H2003

CaH10

C16H1402

C2aH2o03


C13HsO

CBH6GCIO


182

189

239

220

141

158

199

229

34

48


Code
No.


AMINES, AMIDES, IMINES, AND IMIDES


E1456 Acetophenone semicarbazone

E1462 Benzaldehyde semicarbazone

E1505 2,6-Dimethyl-4-heptanone
semicarbazone

E1539 p-Chloroacetophenone
semicarbazone

E1507 p-Methylaoetophenone semicar-
bazone


CqH13N30

CaH9N30



CjoH2,N30



C9H1oClN3O



C IoH aN30


85

84



66



307



53


Ca2HeCIN202 66


98.8

94.2



93.9



91.2


5.8

5.8


2.3


75.5 5.8

Chlo ro-2-nit rod
68.2 2.0


Ave rage
percent
mortality
Not
Treated treated

5.4 4.9

2.6 1.6

2.5 2.5

1.8 2.5

1.7 2.6

1.7 2.6

1.3 2.5

0.7 2.5

0.0 0.0

0.0 0.0


Amount
of
feeding 3/


+++ (b)


E1205

E154

E1559

E1557

E1543

E1544

E1556

E1550

E41

E156


+





++
++ (a)

1-


phenylamine








-7-


Table 1. -- Continued


AMINES, AMIDES,


Code Compounds
No.


E1192 Hydrobenzamide

E1469 -Carvacryl propionamide

E1465 N-Xenyl acetamide

E1466 N-Xenyl propionamide

E1508 Ethyl methyl ketone semicarbazone

E1464 N-Xenyl formamide

E1455 Benzophenone semicarbazone

E1527 p-Chlorobenzene sulfonamide

E1509 Cyclopentanone semicarbazone

E2205 N-(o-Nitrophenylmercapto)-
p-toluidine

E1468 N-Xenyl pyromucamide

E1460 Salicylaldehyde semicarbazone

E1506 Methyl propyl ketone semicar-
bazone

E1597 S-(o-Nitrophenyl) sulfuramine

E1420 2,4,2',4'-Tetrabromodiphenylamine

E1531 alpha-Cyanoacetanilide

E1503 4-Methyl-2-pentanone semicar-
bazone

E1467 N-Xenyl benzamide


C21H18N2

Ci3H1sNO

C14H13NO

C1sH1sNO

CsHiIN3O

C 13H I1NO

C14Ht3N30

C6H6ClO2S

C6HjN30



Cl3H12N20,

C17H12NOz

CsH9N3O2



C6H14N30

C6HGN202S

C1HyBr4N

C9HsN2O



C7H15N30

C1,H 15N0


IMINES, AND IMIDES --CONT.

Number Average
of larvae percent
used in --mortality
treatment 2/ Not
Treated treated
135 29.1 10.7

63 17.5 3.9

49 14.3 3.8

54 13.0 3.8

55 10.9 5.8


65 9.2 3.8

126 7.3 4.8

156 7.2 4.8

79 6.3 5.8


zS


68

177

72

69



77

80


3.4

3.1

3.0



2.9

2.9

2.8

2.6



2.6

2.5


1.7

3.8

5.8



5.8

1.6

3.9

4.8


Amount
of
feeding 3/



+++ (a)

++ (a)

++ (a)

++ (a)

+++ (a)

+++ (a)







+++ (a)


+++ (a)




++ (a)


5.8

3.8








-8-


Table 1. Continued


AMINES, AMIDES, MINES, AND IMIDES-CONT.

Number Average Amount
Cod' Compounds of larvae percent of
No. used in mortality feeding _/
treatment 2/ Not
.......Treated treated


E1575 ?iperoaal semicarbazone

E2224 p-Awinobenzopieenone semicarbazone

E2220 3,4-Dichlioroacetophenone
semicarbazone

E1540 Acetoacetic acid ethyl ester
semicarbazone

E1522 Ae. nyi acetone disemicarbazone

E1576 o-CIiorobanzaldehyde semicarbazone

E1504 Crotanaidenyde semicarbazone

E2221 y,4-Diiet yl-3-pentanone
semicarbazone

E1573 Va.a.lin 6emicarbazone

E142C 2,4,2',4'-Tetrachlorodi-
plhenylamine

E2222 2-Heptano.e semicaroazone

E22457 Oy sin;a:one semicarbazone

E1459 Octano ,emicarbazone

E2244 Beuzii monosemicarbazone

E2204 N-Le,, "aS- (o-nit rophenyl)
ulfuramine

E245 Pirnai oxime ("anti" form)

E246 Piptixvonal oxime ("syn" form)

E1571 Vanillin oxime r


CqH9N303 100 2.5 0.9 ++

C14H14N40 123 2.5 3.1 +++


C9H9CI2N3O



C7H13N30 3

CsH16N602

CSHeCIN3O

CsHSN30



CsH17N3O

CqH,,N303



C12H7C14N

CBH1N30

C7TH3N30

CqHjqN30

C,sHsN302



C13HioN202S

C 8H7NO3

CSH7NO3

C sH *NO g


123



235

91

131

81



132

118



60

138

129

61

155


2.4



2.1

2.0

2.0

1.9



1.9

1.8



1.7

1.7

1.7

1.6

1.3


1.5



2.3

2.1

0.9

5.8


1.5

0.9



3.9

1.5

0.6

5.8

0.6



1.7

0.0

0.0

0.9


+++i (a)




+++ (a)


+++ (a)






+++H (a)









H-







-9-


Table 1. Continued


AMINES, AIDES, IMINES, AND IMIDES-CONT.


Number Average Amount
Code Compounds of larvae percent of
No. used in __mortality feeding 3/
treatment 2/ Not
Treated treated

E270 beta-Anisaldoxime CeHNOa 30 0.0 0.0 ..

E1523 alpha-Ethylbutraldehyde semicar-
bazone C-Hj5N30 61 0.0 2.1 +++ (a)

E1577 Levulinic acid semicarbazone C6H1IN303 125 0.0 0.9 +++



HYDROCARBONS, HALOGENATED AND NITRO DERIVATIVES



E1355 o-Iodonitrobenzene CGH41N02 80 100.0 2.0 0

E4 p-Iodonitrobenzene CcH4INOa 80 100.0 2.0 0

E27 1-Nitronaphthalene C1oH7NO2 84 98.8 2.0 +

E137 Fluorene C13H1o 59 98.3 2.0 0 + (a)

E163 iodosobenzene C.HsIO 52 84.6 2.0 + (a)

E203 2,4-Dinitrotoluene C7HsN204 151 30.0 2.0 0 +++

p~p'-Diiodobiphenyl C1zHSI2 69 17.4 2.0 +++

E1181 alpha, beta-Dibromo-beta-
nitroethylbenzene CSHiBrgNOg 96 8.3 10.7 +++ (a)



HETEROCYCLIC COMPOUNDS


E2 Phenazine

E1538 Phenazine oxide

E1208 Isatin

140 Phenoxathiin (phenothioxin)


CjzHsN2

C1aHaN20

CsHsNO2

C 2.H sOS


69

233

136

55


100.0

100.0

89.9

63.6


2.0

2.3

4.9

2.0


0

0

+

+ ++







- 10-


Table 1. Continued


HETEROCYCLIC COMPOUNDS-CONT.


Number Average Amount
Code Compounds of larvae percent of
No. used in mortality feeding /
treatment 2/ Not
Treated treated


E1532 Dehydrobenzoyl acetic acid

E1194 4-(2,4-Dinitrophenyl) morpholine

E1532 Dehydroacetic acid

E1206 4-Nitrophthalimide

E1421 Piperidine-piperidyl
dithiocarbamate

E1534 Phenothiazine + 100% excess
sulfur

E1193 4-(4-Nitrophenyl) morpholine

E1544 Dioenzalcyclopentanone

E1545 2,3-Dihydroquinidine-12-
carboxylic acid

E2217 N-Fural-S-(o-nitrophenyl)
sulfuramine

E2215 Sulfurized nicotine

E2218 Thianthrene

E2216 3.7-Dimethylthianthrene

E172 Xanthydrol

E173 Xanthone


C18H1204

CloH, N30s

C8H804


C8H4N204



C**H22N2S2


CjoH12N203

C19H180



C13HIN02



C1iHoN203S




C12H8S2

C14Hk$2


C 13H902

C 1311 80 2


80

150

144

185


72

161

232



163



126

133

148

105

41

124


16.1 4.8

10.6 4.9

6.4 6.0

5.8 4.9


4.0



3.7

3.6

2.3


2.0



1.5

1.0

1.0

0.9

0.0

4.2


3.9



4.8

4.9

2.3



2.6



1.5

1.5

1.5

1.5

1.5

3.5


+++ (b)

++(a)





+++ (a)





+++ (b)
+a-++a


+4+




+4+

+4+

+4+











- 11 -


Table 1. --Continued


SULFIDES, DISULFIDES, AND MERCAPTANS

Number Average Amount
Code Compounds of larvae percent of
No. used in mortality feeding 3/
treatment 2/ Not
Treated treated
E1197 Di-(3-nitrophenyl) sulfone C12HsN20rS 125 82.1 4.9 ++ (b)

E1536 p,p'-Dichlorophenyl sulfone C12H8C1202S 78 68.6 4.8 0 ++

E1580 1-(o-Nitrophenylmercapto)
-2-naphthol C16H,INOS 136 2.2 0.9 +++

E2203 4-(o-Nitrophenylmercapto)
resorcinol C1zH9NO4S 158 1.9 1.7 ...

E1581 Aoetonyl-o-nitrophenyl sulfide CqHqN03S 156 0.6 0.9 ...



PHENOLS AND PHENOL ETHERS


E22 4,6-Dinitro-o-oresol C7HsN2O5 90 100.0 2.0 0

E375 p-Isopropoxydiphenylamine C1sH17NO 70 84.3 2.0 0 +

E1535 2,4-Dinitroanisole CzHsN20s 286 78.5 4.8 0 ++

E1210 Quinhydrone C12H1004 100 31.9 3.2 ++ (a)

E1541 Phenoquinone C18H1604 25i 2.4 2.3 ...

E199 N,Nt-Disalicylethylenediamine C16H16NZ02 14 0.3 0.0 +++




1/ Areskap was used as the wetting agent at the rate of 1 gram in 2,000 cc. of water.

2/ Approximately the same numbers of larvae were used in the nontreated tests.

3/ Symbols denote extent of feeding as follows: 0 none, + little, ++ moderate,
... = much. The period of tests was 48 hours except as indicated, the letter (a)
denoting a 72-hour test period and the letter (b) denoting a 96-hour period.








12 -

Table 2.--Results of laboratory tests c- o: rni co .pounds used as insecticides against
newly hatched European corn bori a t the rate of 2 pounds per 100 gallons of
water 1/


Compounds


E1207


E263




E1204

E2

E1538


E248

E1456

E1505



E1535

E1539

E1507

E1537

E1462

E1197

E1208


p-Bromohydrazobenzene


p-Bromoazobenzene

2-Chlorofluorene (crude)

Benzohydrol

Phenazine

Phenazine oxide


Azoxybenzene

Acetophenone semicarbazone

2,6-Dimethyl-4-heptanone
semicarbazone


2,4-Dinitroanisole

p Cnloroacetophenone semicarbazone

p .ethylacetophenone semicarbazon

2,4-Dinitropnenyl acetate

Benzaldehyde semicarbazone

Di-(3-nitrophenyl) sulfone


Isatin


Code
No.


Average
percent
mortality
Not
Treated treated
100.0 5.5

100.0 8.3

99.3 4.5

97.4 5.5


93.9 1.3

93,1 4.5


85.7 8.3

76.2 6.1


of larvae
used in
treatment 2/


118

1.56

285

103

115

247


87

92



95


109

141

86

161


94


69

99


Amount
of
feeding 3/


0 +


0 +




+




++


(a)

(a)




(a)







(a)

(a)


Areskap was used as the wetting

Approximately the same number of

.Symbo I denote extent of feedii
+- mc.. The period or te
noting a 72-hour period of test.


gent at the rate of 1 gram to 2,000 co. of water.

larvae used in the nontreated tests.

l. (0 noneU, t ....little, ++ moderate,
4d hours except is indicated by letter (a) de-


C 1i2 N2


C izHl.b,:N2

C13H9Cl

C13H120


C 12H aN 2

C12H8N20


C12HIoN20


C 9H1N0






C 7H N0z S


C9HoC IN3







C8H9N30



C I 14 0 G
CaHsNO~z


+ (a)




+++




++- ++ 4

+++ (a)

+++ (a)

+++ (a)


61.0

50.4

47.2

41,6


28,2

28.2

27.6

4.2


6.1

4.5


4.5

6.1

4.5

6.1

5.5


5.5








13 -


Table 3.--Results of laboratory tests of some organic compounds used as insecticides against
newly hatched European corn borer larvae at the rate of 1 pound per 100 gallons of
water I/


Compounds


Code
No.


E263 p-Bromoazobenzene

p-Iodonitrobenzene


E22 4,6-Dinitro-o-cresol

E137 Fluorene

2-Chlorofluorene (crude)


E1204 Benzohydrol


E96 p-Iodoazobenzene


E1538 Phenazine oxide

E248 Azoxybenzene


E1456 Acetophenone semicarbazone

E1505 2,6-Dimethyl-4-heptanone
semicarbazone

E1536 p-Chloroacetophenone
semicarbazone


C 12nb13rN2

C6H41NOZ

C 71116N 20 5


C,3HI

C13H9Ci

C13HI20

C12HqIN2

C1zH8NzO

C12HIoNzO

CqHi3N30



C1oH21 N30



CqHioCiN30


iumbe r
)f larvae
ised in
treatment 2/

167

92


93

98

396


93

100


138

30

92



106



100


Average
percent
mortality
Not
Treated treated
100.0 4.5

100.0 4.5

100.0 4.5

100.0 4.5


99.3 3.0

81.7 4.5

79.0 4.5


62.3 4.5

60.0 8.3

20.0 8.7


16.1



2,0


Amount
of
feeding 3/


U -+

0 -+

+







++ (a)

+++ (a)



+++ (a)


1/ Areskap was used as the wetting agent at the rate of 1 gram to 2,000 cc. of spray.


2/ Approximately the same numbers of larvae were used in the nontreated tests.

3/ Symbols denote extent of feeding as follows: 0 = none, + little, ++ = moderate,
... = much. The period of tests was 48 hours except as indicated, the letter (a) de-
noting a 72-hour test period.






LIBRARY
NtATE~ PLANT BOARW


-- - -----------







- 14 -


Discussion

h -Lhcs, laboratory sow mortality produced by the
mz; _& rho do not show in Vna& nn the larvae were killed. As the
larvae w~v, e zartialy sealed in a tu>, .o-tiity way have been due to stomach
...aion, rn. i ae last case the larvae may have
y n odor or taste an1 -to feed. Indications of a re-
La f ob n a sts in the "amines, amides,
i "idcs" group, p i o 2> larvae migrating away from
the siay aes ccngrgatIn- v the tu'e, and remaining there
for most of the period of obseration.

Laon effect was vincl&- '.1 n sprayed with some materials
Trm < v...u of ydrocarKcns 1o at. nd nitro derivatives" prevented
egg iv h h srg age" u repeated tests. Larvae which
did h tii in ests with these mat t, -iliedv ithin a short time and
before any feeding occurred.

i>" materials giving it0-p> e*tla s at dilutions of 4 pounds
per 0 gallons of water, with no :pprn fe2ng, were as follows: p-Bromo-
S p-ooazohnzene, o-io n', p-iodonitrobenzene, phena-
zin- p1eni-ine oxide, and 4,G dln o--o-sol Those which gave approxi-
riaiei Ii p ,cnL ,/ same concentration were: p-Bromo-
hy di .., 99.1 percent; a-c 3 2 percent; l-nitronaphthalene,
98.8 percent; and fluorene, 98.3 percent.

h1 arEsed aL the rate o 1, ; ivtcrial to 100 gallons of water,
thc fo'> i .-aterials continued .... t high. mortalities: p-Bromoazo-
bcnzEi p-iodonitrobenzene, fluo nr 11, e 4,C-dinitro-o-cresol, and 2-chloro-
fluorine (c.ude,. All caused 1C0-perccni mortalities excepting the last one,
which gave 99.3 percent.

From an examination of tIT a 3 appears that the most toxic
o..n: corne from the a-o' ni ro deriatives and halogenated"
roups. Those materials showing high to'i l, n the "amines, amides, imines,
and hi._id' group s -em to lose their lcxicly mch more rapidly upon dilution
than those from the above groups.


FIELD TESTS

Methods

Vh l ateris in ho n~a pi-onise in the laboratory tests
i 9plications of each treatment
we, ]n lud n a, raudon blorl ji, o azt Le in a planting of early market
sweet rci, eaich reIplicate plot b(cn 'uoa w e and 26 feet long. A wheelbar-
row spray' equipped with a small i naino and a single spray rod and







- 15 -


nozzle with a 16-foot hose, was used in making the applications. A schedule
of 4 applications at 5-day intervals, beginning with the first hatch, was fol-
lowed. Ten consecutive plants from each of the 2 middle rows of each plot were
dissected to obtain data on the effects of treatments. The first 3 plants at
the ends of the rows were left as buffers.

In 1939, as only limited quantities of the materials were available for
the field tests, they were applied at the low rate of 1 pound of material to
100 gallons of water, supplemented by a wetting agent (Areskap) at the rate of
1 part to 2,000 parts of water. In 1943 the applications were made at the rate
of 3 pounds of the material per 100 gallons of water, plus Areskap at the rate
of 1 part to 2,500 parts of water.

Results

The results of the field tests of 1939 are shown in table 4 and of the
field tests of 1940 in table 5.


Table 4. -- Results of the field tests of 1939 against the European corn borer


Pounds per Percent reduction of borers
Code Materials 1/ 100 gallons in treated plants over plants
No. not treated


2-Chlorofluorene 1 67.9

E249 Azobenzene 1 59.1

E22 4,6-Dinitro-o-cresol 1 55.0

E96 p-Iodoazobenzene 1 49.1

263 p-Bromoazobenzene 46.0

p-Iodonitrobenzene 1 44.4

E137 Fluorene 1 43.7

E1204 BenzohydroJ 1 39.8


Ground derris
(standard treatment)


4 (approximately
4% rotenone)


1/ Areskap was added to each of the above treatments at the rate of
1 part to 2,000 parts of water.


93.8






16 -

Table 5. Results of the field tests of 1940 against the European Corn borer


Code Materials l/ Pounds per 100 Percent reduction of borers in treated plants
No. gallons of water over plants not treated

E 249 Azobenzene 3 74.9

E2 Phenazine 3 74.4

E1538 Phenazine oxide 3 58.9

Ground derris
(standard treatment) 4 (4.7% rotenone) 94.1

l/ Areskap was added to each of the above treatments at the rate of 1 part to 2,500 parts
water.
---0---


Table 6. -- Plant tolerance of organic compounds used in the field tests of
1939 and 1940


Code
No.


Materials


2-Chlorofluorene

E249 Azobenzene


Pounds per
100 gallons

1


E22 4.6-Dinitro-o-cresol


E96 p-Iodoazobenzene

E263 p-Bromoazobenzene

p-Iodonitrobenzene

E 137 Fluorene

E1214 Benzohydrol

E249 AzobeLn

E2 Phenazine

E1538 PI~enazinT1 oxide

Ground derris I/

1/ koteno~e -ontent of derris


1




1

1






3
3



4

used in 1939


Tolerance


No injury

Slight injury consisting of yellow blotches
in whorls

Burned severely, stunted plants, completely
destroyed many leaves

No injury

No injury

No injury

No injury

No injury

Slight injury, bleached unrolled leaves in whorl

Very severe injury, plots nearly a total loss

Very severe injury, plots nearly a total loss

No injury

wa 4 percent, and in 1940, 4.7 percent.







- 17-


Discussion

While of the materials tested in the field, 2-chlorofluorene, azoben-
zene, 4,6-dinitro-o-cresol, and phenazine gave the highest reductions in borer
populations, at the concentrations tested, none of them provided as satisfac-
tory protection to the corn plant as derris, the standard for comparison. In
,addition, a number of the materials caused more or less injury to the corn plant,
as shown in table 6, whereas no injury resulted from the derris applications.

It may also be noted (tables 1 to 5, inclusive) that larval mortalities
following- field applications were generally lower than those caused by the
same materials in the laboratory tests. This condition may be associated with
(1) a smaller proportion of the feeding area in the field being covered with
the materials due to the rapid growth of the corn plant, (2) less opportunity
for fumigation effect on the exposed corn plants than in the closed tubes, (3)
varying proportions of the newly hatched larvae being exposed to the immediate
effects of the treatments due to migration habits of the Lorer and residue
losses from weather effects, more resistant older larvae being thus exposed
to the insecticidal residues, or (4) the loss of toxicity from volatilization
of the material when exposed in the field. Nevertheless, the performance of
2-chlorofluorene when used at 1 pound to 100 gallons of water was very promis-
ing (67.9 percent reduction in borers) and, as its use was accompanied by no
plant injury, it is probably the most outstanding of the new compounds tested
to date. While no reports of any harmful effects have been received from
various entomologists testing the material, it is suggested that suitable pre-
cautions be observed in its use pending the results of extensive pharmacological
tests which are now being conducted.

The optimum concentrations of the organic compounds have not been de-
termined, and further tests of the more promising materials at higher concen-
trations are necessary prior to final evaluation of their insecticidal effective-
ness. It is probable that if the tests of 1939 had been conducted at the rate
of 3 pounds to 100 gallons of water a much higher mortality would have resulted.














































Figure l.--Cages used in laboratory toxicity
texts against the European corn borer.









































Figure 2.-Cauliflower leaves after a 48-hour test. A, showing heavy feeding and
living larvae on nontreated leaves; B, showing no feeding and dead larvae
following treatment with 2-chlorofluorene, a compound highly toxic to the borer.




UNIVERSITY OF FLORIDA

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