December 1941 E-557 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 «L 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- ment of Agriculture Experimental Farm southwest of Toledo in 1939 and 1940. All the compounds were supplied by the Division of Insecticide Inv estiga- tions, and the laboratory and field tests vere made by the Division of Cereal and Forage Insect Investigations. - 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 a 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 cut into small sections, each containing an egg mass. These passes were then placed in a gallon earthenware jar containing moist blotting paper and allowed to incubate. From 20 to 100 egg masses m 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 ^integra- tion of these leaves contributed to high mortalities among the newly hatched borers confined with them. For this reason cauliflower leaves, which do "ot 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 72 or 96 hours in the earlv tests This period inter was reduced to 48 hours because it is advantaleous' in corn "borer control to secure a rapid kill Otherwise he • rapid growth of the corn plant tends to expose new, untreated growth at the Jeed?n| 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 wore prepared by grinding with a stirring rod 0.25 g of the compound in a beaker oontalning a little water pins all the wetting IgLt sodium .onosulfonate of butylphenylph.no! (Areskap) required to furnish a dilution at the rate of 1 g. of wetting agent to ^.000 oc . of - 3 water in the completed spray. After the material had been finely ground, enough water was added to bring the dilution of the compound to the rate desired. This preparation was sprayed thoroughly upon fresh green leaves with a small atomizer connected to an air-pressure tank fitted with a low-capacity automatic air regulator set for 10 pounds' pressure. As soon as the surface water had evaporated from the leaves they were made into a small roll and inserted into a Lest tube 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). Observations were made daily, and, on completion of the test period, records were made of the dead and living larvae, the condition of the leaves, and the amount of feeding that had occurred (fig. 2). Materials first were tested at the rate of 4 pounds per 100 gallons of water. Those materials that gave high mortality with little or no feeding were retested at either 2 pounds or 1 pound per 100 gallons of water, or both. Results Ail 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 some of the materials could be placed in any one of several groups, but as this system has been used in recording tests of synthetic organic compounds against other insects, it is used in reporting this work. Table i. — Results of laboratory tests of some organic compounds used as insecticides against newly hatched European corn borer larvae at a dilution of 4 pounds to 100 gallon of water 1/ ACIDS, ALCOHOLS, AND ESTERS Code No. Compounds Number Average Amount of larvae percent of used in mortality feeding 3/ treatment 2/ Not Treated treated E1204 Benzohydrol Ci 3 Hi 2 E1569 3,4-Methyleneoxybenzai-p-araino benzoic acid E131 4,6-Dinitro-o-cresol acetate E1537 2,4-Dinitrophenol acetate E42 9-Fluorenol E11S5 Ethyl ester of 4-acetyl-3- hydroxy-2-naphthoic acid E379 Diphenyl ester of carbonic acid Ci 3 Hio0 3 E1570 3-Methoxy-4-hydroxybenzal-p- aminobenzoic acid E2211 Benzoyl peroxide 133 94. 6 3.2 (a) C 15 HiiN0 4 307 91.2 2.3 + C9H8N2O6 64 89.0 2.0 - ++ (a) C 8 H 6 N 2 0c 198 80.3 4.8 - ++ C13H10O 70 17.1 2.0 ++ C15H14O4 130 12.2 4.9 +++ (b) C 13 Hio0 3 128 7.1 3.2 +++ (a) C 15 Hi 3 N0 4 127 4.7 0.9 +++ C14H10O4 163 0.6 1.7 +++ AZ0, HYDRAZ0, AND RELATED COMPOUNDS E96 p-Iodoazobenzene E263 p-Bromoazobenzene E1207 p-Bromohydrazobenzene C12H9IN2 80 100.0 2.0 Ci2H 9 BrN 2 79 100.0 2.0 C12H11B1N2 217 99.1 4.9 - + (a 1/ Areskap was used as the wetting age.it 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: none, + . little, ++ . moderate, much. The period of tests was 48 aours except aj indicate;!, the letter (a) denot- ing a 72-hour test period and the letter (b) denoting a 96-hour period. Table 1. — Continued AZO, HYDRAZO, AND RELATED COMPOUNDS ( Continued j Code" No. Compounds Number of larvae used in treatment 2 Average percent mortality Amount of feeding ! 3/ / Treated Not treated "E24S A2oxy"benzene Ci 2 H 10 N 2 108 98.2 8.3 + (a) E1167 p,p '-Diiodoazoxybenzene Ci 2 H 8 l2N 2 204 36.6 10.7 ++ (a) E1514 l-O-Tolylazo-2-naphthylaaine C17H15N3 117 29.6 2.1 ++ (a) E1168 p,p'-Azobis-(beazoic acid) C 14 HioN 2 04 138 26.5 10.7 +++ (a) E1171 p,p '-Azobisbiphenyl C24H18N2 124 16.9 10.7 +++ (a) E1170 p,p '-Hydrazobisbiphenyl C 2 4H 2 oN 2 126 16.4 10.7 +++ (a) E1171 p,p '-Azobisphenoi- C12H10N2O2 126 12.1 10.7 +++ (aj E1173 p,p'-Azobisphenetoie C16H18N2O2 102 11.7 10.7 +++ (a) E126 l-Phenylazo-2-naphthylamine C16H13N3 115 9.6 2.1 +++ (a) E1513 l-Xylylazo-2-naphthol C 18 Hi6N 2 127 4.9 2.1 +++ (a) E1516 alpha.- (o-Mitro-p-an-' sylazo) " -o-ac'etbt'oluide C18H13N4O5 110 4.0 2.1 +++ (a) E1513 l-Xylylazoxylazo-2-naphthol C 26 H 2 4M40 179 2.9 2.1 +++ (a) E1519 l-(o-Nitro-p-tolylazo) -2-naphthol C17M13N3O3 132 2.7 2.1 +++ (aj E453 l-(p-Phenylazophenylazo) -2-naphthol C2 2 Hi 6 N 4 135 2.4 2.1 +++ (a) E1321 1- ( o-Tolylazo ) -2-naphthol Ci 7 H 14 N20 99 2.4 2.1 +++ (a) E1520 l-(2,4-Dinitrophenylazo) -2-naphthol C16H10N4O5 146 2.2 2.1 +++ (a) alpha- ( o-Nit ro-p-tolylazo ) acetoacetanilide C17H18N4O4 119 1.2 2.1 +++ (a) i-(u-Chloro-p-nitrophenylazo) -2-naphthol C16H10CIN3O3 141 1.3 2.1 f++ (a) - 6 - Table 1 Continued ALDEHYDES AND KETONES Code No. Compounds Number Average Amount of larvae percent of used in mortality feeding 3/ treatment 2/ Not Treated treated E1205 1 , o-Diphenyl-3-pentadienone E154 3,4-Dichloroacetophenone E1559 Dibenzaltriacetophenone (Isomer B) E1557 Benzaldiacetophenone E1543 Dianisal cyclopentanone E1544 Dipiperonal cyclopentanone E1556 Anisalacetophenone El 553 2-Hydroxybenzaldiacetophenone E41 9-Fluorenone E156 p, omega-Dichloroacetophenone C17H140 182 C 8 H 6 C1 2 189 C38H32O3 239 C23H20O2 220 C 2 iH 2 o0 3 141 C21H16O5 158 C16H14O2 199 C23H20O3 229 Ci 3 H 8 34 C 8 H 6 C1 2 48 5.4 2.6 2.5 1.8 1.7 1.7 1.3 0.0 0.0 4.9 1.6 2.5 2.5 2.6 2.6 2.5 +++ (b) 0.7 2.5 0.0 0.0 AMINES, AMIDES, IMINES, AND IMIDES E1456 Acetophenone semicarbazone E1462 Benzaldehyde semicarbazone C9H13N30 85 98.8 5.8 (a) C 8 H 9 N 3 84 94.2 5.8 + (a; E1505 2,6-Dimethyl-4-heptanone semicarbazone C lo H2iN 3 66 93 . 9 5.8 + (a) E1539 p-Chloroacetophenone semicarbazone C 9 H 10 C1N 3 307 91.2 2.3 E1507 p-Methylacetophenone semicar- bazone C 1 oH 1 3 N 3 53 75.5 5.8 ++ (a) phenylamine Ci 2 H 9 ClN 2 2 66 Chlo ro-2-nit rod 68.2 2.0 ++ Table 1 - 7 - AMINES, AMIDES. IMINES, AND IMIDES — CONT. Number Average Amount Code Compounds of larvae percent of No. used in treatment 2/ mortali tv feeding 3/ Not Treated treated E1192 Hydrobenzamide C21H18N2 135 29.1 10.7 +++ (a) E1469 Carvacryl propionamide Ci 3 Hi 9 N0 63 17.5 3.9 ++ (a) E1465 N-Xenyl acetamide C14H13NO 49 14.3 3.8 ++ (a) E1456 N-Xenyl propionamide Ci 5 H 15 N0 54 13.0 3.8 ++ (a) E1508 Ethyl methyl ketone semicarbazone C5H11N3O 55 10.9 5.8 +++ (a) E1464 N-Xenyl formamide C13H11NO 65 9.2 3.8 +++ (a) E1455 Benzophenone semicarbazone C14H13N3O 126 7.3 4.8 +++ E1527 p-Chlorobenzene sulfonamide C 6 H 6 C10 2 S 156 7.2 4.8 +++ E1509 Cyclopentanone semicarbazone C6H11N3O 79 6.3 5.8 +++ (a) E2205 N-(o-Nitrophenylmercapto)- p-toluidine C13H12N2O2S 169 3.4 1.7 +++ El 468 N-Xenyl pyromucamide C17H12NO2 65 3.1 3.8 +++ (a) E1460 Salicylaldehyde semicarbazone C 8 H 9 N 3 02 67 3.0 5.8 +++ (a) E1506 Methyl propyl ketone semicar- bazone C6H14N3O 68 2.9 5.8 +++ (a) E1597 S-(o-Nitrophenyl) sulfuramine C6H5N2O2S 177 2.9 1.6 +++ E1420 2,4,2' ,4'-Tetrabromodiphenylamine Ci2H 7 Br 4 N 72 2.8 3.9 +++ (a) E1531 alpha-Cyanoacetanilide C9H8N2O 69 2.6 4.8 +++ E1503 4-Methyl-2-pentanone semicar- bazone C 7 H 15 N30 77 2.6 5.8 +++ (a) E1467 N-Xenyl benzamide C19H15NO 80 2.5 3.8 +++ (a) - 8 - Table 1 Continued MINES, AMIDES, MINES, AND IMIDES— CONT. Codfc No. Compounds Number Average Amount of larvae percent of used in mortality Seeding 3/ treatment 2/ Not Treated treated E1575 Piperonal semicarbazone C9H 9 N 3 03 100 2.5 0.9 E2224 p-A&iinobenzophenone semicarbazone C14H14N4O 123 2.5 3.1 E2220 3 , 4-Dichloroacetophenone semicarbazone C9H9CI2N3O 123 2.4 1.5 E154C Acetoacetic acid ethyl ester semicarbazone C7H13N3O3 235 2.1 2.3 E1522 Aostonyi acetone disemicarbazone C 8 H 16 N- 6 2 91 2.0 2.1 E1576 o-Chlorobanzaldehyde semicarbazone C 8 H8C1N 3 131 2.0 0.9 E1504 Crotanaidehyde semicaroazone C5H9N3O 81 1.9 5.8 E2221 2 , 4-Dimethyl-3-pentanone semicarbazone C 8 Hi 7 N 3 132 1.9 1.5 El 573 Vanillin semicarbazone C9H11N3O3 118 1.8 0.9 E142C 2,4,2' ,4'-Tetrachlorodi- phenylamine C12H7CI4N 60 1.7 3.9 E2222 2-H^ptanone semicaroazone C 8 Hi 7 N 3 138 1.7 1.5 E2245 .^xanone semicarbazone C7H13N3O 129 1.7 0.6 E1459 Octanone semicarbazone C9H19N3O 61 1.6 5.8 E2244 Benzil monosemicarbazone CisHisNsOz 155 1.3 0.6 E2204 N-Benzal-S-(o-nitrophenyl ) sulfuramine C13H10N2O2S 156 0.7 1.7 E245 Piperonal oxime ("anti" form) C8H7NO3 37 0.3 0.0 E246 Piperonal oxime ("syn" form) C 8 H 7 N0 3 44 0.0 0.0 E1571 "anillin oxime C 3 H ft N0 8 143 0.0 0.9 +++ (a) (a) +++ (a) (a) Table 1. — Continued AMINES, AMIDES, IMINES, AND IMIDES— CONT. Code Compounds No. Number Average Amount of larvae percent of used in ...mortality feeding 3/ treatment 2/ Not Treated treated E270 beta-Anisaldoxime C8H9NO2 E1523 alpha-Ethylbutraldehyde semicar- bazone C7H15N3O E1577 Levulinic acid semicarbazone C6H11N3O3 30 61 125 0.0 0.0 0.0 2.1 0.0 0.9 +++ (a) HYDROCARBONS, HALOGENATED AND NITRO DERIVATIVES E1355 o-Iodonitrobenzene E4 p-Iodonitrobenzene E27 1-Nitronaphthalene E137 Fluorene E163 xodosobenzene E203 2,4-Dinitrotoluene p,p'-Diiodobiphenyl E1181 alpha, beta-Dibromo-beta- nitroethylbenzene C 6 H 4 IN0 2 80 100.0 2.0 C 6 H 4 IN0 2 80 100.0 2.0 C10H7NO2 84 98.8 2.0 C13H10 59 98.3 2.0 C 6 H 5 I0 52 84. 2.0 C7H6N2O4 151 30.0 2.0 Ci 2 H 8 I 2 69 . 17.4 2.0 C 8 H7Br 2 N02 96 8.3 10.7 (a) (a) - +++ (a) HETEROCYCLIC COMPOUNDS E2 Phenazine E1538 Phenazine oxide E1208 Isatin E140 Phenoxathiin (phenothioxinj C12H8N2 69 100.0 2.0 C12H8N20 233 100.0 2.3 C8H5N02 136 89.9 4.9 C 1 2 H 8 os 55 63.6 2.0