Diethyl Phosphorothioate Research Articles

Residues of V-C 13 Nemacide in Animal Tissues

Analysis of samples of omental fat taken from cattle, sheep, and goats at intervals after spraying with a 0.5% suspension of Nemacide® O -(2,4-dichlorophenyl) O,O -diethyl phosphorothioate showed that residues of the insecticide were deposited in the fatty tissues of all treated animals and persisted in detectable amounts for 6 to 8 weeks. Analysis of samples of eight body tissues taken from animals 2,27, and 57 days after spraying showed that residues were found in all the tissues of a sheep slaughtered 2 days after spraying, but were not found in significant amounts in the tissues of these animals 27 and 57 days after spraying.

Development of Resistance to Insecticides by the Onion Maggot, Hylemya antiqua, in Minnesota1

The onion maggot, Hylemya antiqua (Meigen), has developed a high degree of resistance to the chlorinated hydrocarbon insecticides in the Minneapolis area. Under conditions of a severe maggot infestation at Fridley, Minn., applications of V-C 13 Nemacide® ( O -2,4 diehlorophenyl O,O -diethyl phosphorothioate), ethion, and diazinon at 1 lb. actual toxicant per acre and carbophenothion at 2 lbs. actual per acre in the seed furrow gave excellent control, but plots treated with heptachlor, dieldrin, aldrin, and endrin were indistinguishable in appearance from the untreated checks. Experiments at Castle Rock, Minn., during 1960, 1961, and 1962 indicated that aldrin, dieldrin, endrin, and heptachlor are still effective in controlling the onion maggot in this area. Onion maggot, damping off, smut ( Urocystis cepulae Frost.), and pink root ( Pyrenochaeta terrestris (Hansen) Gorenz, J. C. Walker, and Larson) aII contributed to a loss of stand in these plots. Two granular formulations, one containing 5% V-C 13 Nemacide +5% thiram (bis(dimethylthiocarbamoyl)disulfide) and the other containing 5% ethion+5% thiram, gave excellent control of maggots and good control of smut and pink root when applied at 2 lbs. actual toxicant per acre in the seed furrow. Onion growers at Hollandale, Minn., appeared to be controlling the onion maggot satisfactorily in 1961 by using a mixture of 2 oz. 75% dieldrin and 1 oz. 75% thiram per pound of seed in the planter box; however, experimental evidence indicated that maggots were becoming resistant to dieldrin and heptachlor in this locality in 1962.

Tests with Insecticides for Control of Lice on Goats and Sheep

In laboratory tests, Angora goats infested with biting lice ( Bovicola spp.) were dipped in 13 insecticides. All but 0.1% and 0.25% chlorobenzilate and 0.1% carbaryl freed goats of lice. In field tests, 22 herds of goats infested with biting lice and goat sucking lice ( Linognathus stenopsis (Burmerister)) and 3 flocks of sheep infested with sheep biting lice ( Bovicola ovis (L.)) were sprayed with 11 insecticides. All except 0.5% methoxychlor controlled existing populations of motile lice. Biting lice were controlled from shearing to shearing on goats sprayed with 0.25% Ruelene® ( O -4- tert -butyl-2-chlorophenyl O -methyl methylphosphoramidate) and on sheep sprayed with 0.25% General Chemical 4072 (2-chloro-1(2,4-dichlorophenyl)vinyl diethyl phosphate) and 0.25% V-C 13 Nemacide® (0-2,4-dichlorophenyl O,O -diethyl phosphorothioate). Sucking lice were controlled from shearing to shearing on goats sprayed with 0.25% General Chemical 472 and 0.25% Relene.

Toxicity to House Flies and Horn Flies of Manure from Insecticide-Fed Cattle

In feeding tests extending 91 days, 0.5 and 1 mg./kg./day of Co-ral® ( O, O -diethyl 0-3-chloro-4-methyl-2-oxo-HI-l-benzopyrnn-7-yl phosphorothioate) and 1 mg./kg./day of Bayer 2:2408 ( O, O -diethyl O-naphthalimido phosphorothioate) were essentially 100% effective in preventing development of larvae of horn flies, Haematobia irritans (L.), and partially effective against house flies, Musca domestica L., in manure of cattle. In 10-day feeding tests with 10 insecticides, Bayer 37341 ( O, O -diethyl 0-(4-methylthio-3,5-xylyl) phosphorothioate) at 5 mg./kg./dny, Bayer 37342 ( O, O -dimethyl 0-4-(methylthio)-3,5-xylyl phosphorothioate) at 10 mg./kg./day, and General Chemical 4072 (2-chloro-l-(2,4-dichlorophenyl) vinyl diethyl phosphate) at 2.5 mg./kg./day were effective against both species. Famophos ( O, O -dimethyl O-p -(dimcthylsulfamoyl)phenyl phosphorothioate) at 10 mg./kg./day, V-C 13 Nemacide® ( O -2,4-dichlorophenyl O, O -diethyl phosphorothioate) at 3 mg./kg./day, and Bayer 29493 ( O, O -dimethyl O -[4-(methylthio)-7ll-tolyl] phosphorothioate) and Stauffer R-1504 ( O, O -dimethyl S -phthalimidomethyl phosphorodithioate) both at 2.5 mg./kg./day, were effective against horn flies but only partially so against house flies.

Distribution and Control of Cyclodiene-Resistant Wireworms Attacking Tobacco in North Carolina1

A survey of wireworm resistance to cyclodiene insecticides on tobacco was made in 1962. It was shown that Conoderus vespertinus (F.) and C. falli Lane were both present in fields properly treated with insecticides. Larvae of the latter species were found in tobacco only in the southeastern section of North Carolina whereas C. vespertinus was present in all tobacco growing areas in the southern and eastern counties of the State. Field-screening tests on resistant populations showed that the following materials were promising as broadcast treatments: parathion, diazinon, Telodrin® (1, 3, 4, 5, 6, 7, 8, 8-octachloro-1, 3, 3a, 4, 7, 7a-hexahydro-4,7-methanoisobenzofuran), VC-13 Nemacide® ( O- 2, 4-dichlorophenyl O-O -diethyl phosphorothioate), Bayer 38156( O -ethyl S-p -toyl ethylphosphonodithioate), and Cynem® ( O, O -diethyl O -2-pyrazinyl phosphorothioate; also known as Zinophos or AC-18133). Transplanting water treatments of the following materials gave good results: diazinon, Bayer 38156, Bayer 25141 ( O, O -diethyl O-p -methylsulfinylphenyl phosphorothioate, UC-8305 ( p -chloro-5-methyl- p -thio-2,4,3-dioxaphosphabicyelo [4.4.0] decane), Stauffer N-2788 ( O -ethyl- S-p -tolyl ethylphosphonodithioate) same as Bayer 38156; and GC-4072 (diethyl-1-(2-4-dichlorophenyl)-2-chlorovinyl phosphate).

Development of Insecticidal Resistance by Soil Insects in Canada1

Tests on soil insects collected from a number of areas in Canada indicated that the dipterous insects are rapidly becoming resistant to the cyclodiene insecticides. Four species of root maggots were found to be resistant; the onion maggot, Hylemya antiqua (Meigen); the seed-corn maggot, H. cilicrura (Rondami) and the closely related species, H. liturata (Meigen); and the cabbage maggot, H. brassicae (Bouche). The spotted root fly, Euxesta notata (Wiedemann), exhibited a high degree of tolerance to aldrin and dieldrin. Diazinon® (D,O-diethyl O -(2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothioate), Trithion® ( O,O -diethyl S-p -chlorophenylthiomethyl phosphorodithioate), ethion, and V-C-13 ( O -, 2,4-dichlorophenyl O,O -diethyl phosphorothioate) were all highly toxic to adult flies of the Anthomyiidae. The Common cutworm species of economic importance in southwestern Ontario, Agrotis ipsilon (Hufnagel) and Peridroma saucia (Hubner), showed no indication of cyclodiene resistance. The organophosphate insecticides were generally less toxic to cutworms than the cyclodiene insecticides. The dark-sided cutworm, Euxoa messoria (Harris), was highly tolerant to dieldrin, DDT, and Diazinon. Cyclodiene resistance has developed in areas where broadcast applications of insecticides have been applied to the soil over several consecutive years. It was suggested that, in order to slow the development of oregano phosphate resistance, procedures other than broadcast applications should be utilized with the oregano phosphate insecticides when feasible.

Toxicological Studies of Compound VC 1-13 in Livestock

Toxicity studies in livestock were carried out using a compound known chemically as O -2,4-dichlorophenyl O,O -diethyl phosphorothioate (V-C 13 Nemacide). The maximal safe and minimal toxic dermal dosages as determined for the livestock used in these studies appeared to the as follows: These dosages were determined for animals in good health and body condition. Death and signs of toxicosis were produced in emaciated goats and sheep dipped in 0.25% and 0.5% concentration, respectively.

3. The reactivity of organophosphorus compounds. Part XI. High-temperature decomposition of S-2-diethylaminoethyl diethyl phosphorothioate (“Amiton”)

3. The reactivity of organophosphorus compounds. Part XI. High-temperature decomposition of S-2-diethylaminoethyl diethyl phosphorothioate (“Amiton”)

Experiments on the Control of Poultry Lice1

Control of poultry lice by spraying the bird, dusting the litter, and feeding has been attempted with several new insecticides. Sprays of dimethoate, and Hercules 426 (5-dichloromethyl-1,2,3, 4,7,7-hexachlorobicyelo[2.2.1]hept-5-ene) gave mortalities similar to the malathion standard at 0.0.5%. Dibrom® (1,2-dibromo-2,2-dichloroethyl dimethyl phosphate) was outstanding in providing 100% mortality at 0.025%. Sevin® (1-napthyl N -methylcarbamate) and Co-Ral® ( O -(3 chloro-4-methyllllnbelliferone) O, O -diethyl phosphorothioate) in 5% dusts were effective at one-half pound to 40 square feet under controlled conditions but were erratic under variable farm conditions. Orally administered toxicants were generally ineffective.

Evaluation of New Materials for Codling Moth Control in Washington1

Field studies were conducted during 1958, 1959 and 1960 to determine the effectiveness of several insecticides for the control of codling moth ( Carpocapsa pomonella (L.)) in apple orchards which had had a high percentage of wormy fruit during the previous year. Sevin® (1-naphthyl N -methylcarbamate) at 1 pound of 50% wettable powder per 100 gallons of water or Guthion® ( O, O -dimethyl S -4-oxo-1,2,3-benzotriazin-3-(4H)-ylmethyl phosphorodithioate) ar 0.75 pound gave excellent codling moth control. At a dosage of 1.5 pounds per 100 gallons of water both of these materials provided good control when the interval between sprays was extended from 21 to 28 days. Ethyl Guthion® ( O, O -diethyl S -4-oxo-l,2,3-benzotriazin-8(4 H )-ylmethyl phosphorodithioate) and Diazinon® ( O, O -diethyl O -(2 isopropyl-6-methyl-4-pyrimidyl) thiophosphate) were not consistently as effective as Sevin or Guthion. Control with ethion was good in 1958 and 1959 but was poor during 1960. Trithion® ( S -( p -chlorophenylthio methyl) O, O -diethyl phosphorodithioate) gave good control but was phytotoxic to apples. Other materials which showed considerable promise for codling moth control were dimethoate, phosphamidon, Bayer 29493 ( O, O -dimethyl O -[4-(methylthio)- m -tolyl] phosphorothioate), and Bayer 22408 (Naphthaloximido- O, O -diethyl phosphorothioate). The materials which did not provide adequate control with Ryania (ground stems of Ryania speciosa ), were: Dilan (2-nitro 1,1-bis( p -chlorophenyl)propane and butane mixture (1: 2 ratio)), Kepone® (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta [cd] pentalen-2-one), and DDT. The addition of either parathion or malathion to DDT resulted in good control.

A Comparison of Co-Ral, Ronnel, and Ruelene Dusts for Screw-Worm Control

Live stock shipped into the Southeast from areas infested with screw-worms ( Callitroga hominirorax (Coquerel)) are examined and treated with insecticide at livestock inspection stations operated by the U. S. Department of Agriculture. Tests were undertaken to develop a dust treatment as an alternative for spraying so that wetting of the animals in cold weather could be avoided. In experiments using artificially infested animals, power dusting was as efficient as hand dusting, and Co-Ral® ( O -(3-chlolro-4-methylumbelliferone) O,O -diethyl phosphorothioate) dust was more effective than Ruelene® (0-4-tert t-butyl-2-chlorophenyl O -methyl methylphosphoramidate) or ronnel dusts in killing screw-worms and preventing reinfestation for 48 hours.

Toxicity to Face Fly and House Fly Larvae of Feces from Insecticide-Fed Cattle

Co-Ral® ( O -(3-chloro-4-methylumbelliferone) O,O -diethyl phosphorothioate), Bayer 22408 ( O,O -diethyl O -naphthalimido phosphorothioate), and ronnel were administered to Holstein heifers in the grain ration for 5 consecutive days to determine whether the treated animals would produce droppings that were toxic to the larvae of face flies ( Musca autumnalis DeGeer) and house flies ( Musca domestica L.). Tests in which the feces from the treated animals were infested with newly hatched larvae showed that Co-Ral and Bayer 22408 completely inhibited the development of face fly larvae at dosages of 1.0 and 0.5 milligrams per kilogram of animal weight. House fly larvae failed to survive at the 1.0 mg./kg. dosages of both chemicals. The 0.5 mg./kg. dosages were highly effective, but did not completely stop house fly development. Feces from animals fed ronnel at 5.0 mg./kg. gave complete kill of face fly and house fly larvae. Ronnel at 2.5 mg./kg. was effective against the larvae of face flies, but not house flies.

Toxicity to Fly Larvae of the Feces of Insecticide-Fed Cattle

Studies were conducted on the toxicity to newly hatched house fly larvae ( Musca domestica L.) of the feces of cattle fed 25 different compounds. The materials were incorporated in the animals’ diet for 5 days and fecal samples collected for tests at different intervals during feeding and after it was discontinued. Fourteen of the 25 compounds were not completely lethal to the larvae at the dosages tested. Bayer 22408 ( O,O -diethyl O -naphthalimido phosphorothioate) and Co-Ral® ( O -(3-chloro-4-methylumbelliferone) O,O -diethyl phosphorothioate), the two most effective materials, were lethal to the larvae when administered to the animals at dosages as low as 1 mg./kg. Comparative data are presented on the susceptibility of newly hatched larvae of the house fly, stable fly ( Stomoxys calcitrans (L.)), and horn fly ( Siphona irritans (L.)) to four of the more effective insecticides.

In Vitro Stability and Recovery of Insecticides from Milk1

Recoveries of Sevin® (1-naphthyl N -methylcarbamate), Kepone® (decachlorooctahydro-1,3,4-metheno-21f-cyclobuta [ed] pentalen-2-one), Bayer 29493 ( O,O -dimethyl O -[4-(methylthio)- m -tolyl] phosphorothioate), Bayer 22408 ( O -naphthalimido- O,O -diethyl phosphorothioate), Ruelene® ( O -4-tert-butyl-2-chlorophenyl O -methyl methylphosphoramidate), and CoRal® ( O,O -diethyI O -(3-ch loro-4-methylumbelliferonc) phosphorothioate) from milk ranged from 87% to 97% using acetonitrile and chloroform as the primary extraction solvents and acetonitrile- N -hexane as a cleanup procedure. This extraction procedure was somewhat less effective for removing known amounts of DDT and dieldrin from milk. Acetonitrile-chloroform extraction of milk was usually more efficient for removing insecticides than was a 2: 1 mixture of diethyl ether and N -hexane. Ruelene, Bayer 22408, and Bayer 29493 were stable In Vitro in raw milk for periods up to 14 days of incubation, but after 3 days incubation, some Co-Ral equivalents remained in the milk residue following acetonitrile-chloroform extraction.

Practical Application Methods for Systemic Cattle Grub Control1

The cattle grubs Hypoderma lineatum (de Vill.) and H. bovis (L.) were controlled through various methods of applying three systemic insecticides: Co-Ral® ( O -(3-chloro-4-methylumbelliferone) O,O -diethyl phosphorothioate), Dowco 109 ( O -(4- tert -butyl-2-chlorophenyl) O -methyl methylphosphoramidothioate) and Ruelene® (4- tert -butyl-2-chlorophenyl methyl methylphosphoramidate). In a series of tests these three systemic insecticides were applied at low pressures (80 to 100 pounds). Grub control by Co-Ral was excellent and unaffected by the addition of household detergent at the rate of one-half pound per 25 gallons of spray. Backrubber applications of 5% Ruelene as an oil solution failed to systemically control the cattle grubs. Spray-Dip machine applications of Co-Ral and Ruelene were moderately effective. No increase in gains in weight attributable to the systemic grub control was observed.

Screw-Worm Control with Insecticide Sprays1

Experiments were conducted to find a safe an inexpensive insecticide that is toxic to young larvae and has a 2-day residual effect. In laboratory tests Bayer 22408 ( O,O -diethyl O -naphthalimido phosphorothioate) gave excellent control of screw-wroms ( Callitroga hominivorax (Cqrl.)) in sheep. In field trials it performed as well as Co-Ral® ( O (3-chloro0-4-methylumbelliferone) O,O -diethyl phosphorothioate) on sheep but not no cattle. Further critical laboratory tests confirmed the field results.

Toxicity of Organic Phosphorus Insecticides to Horses

Tests were made on 48 horses to find the optimal dosage of some organic phosphorus insecticides for use against horse bots. (Gasterophilidae). The animals were treated with Co-Ral® ( O -(3-chloro-4-methylumbelliferone) O, O -diethyl phosphorothioate), dimethoate, DOWCO 105® ( O -methyl O -(4- tert -butyl chlorophenyl) ethylphosphoramidothioate), DOWCO 109® ( O - (4- tert butyl-2-chlorophenyl) O -methyl methylphosphoramidotioate), ronnel, Ruelene® (4- tert -butyl-2-chlorophenyl methyl methylphosphoramidate), DDVP, and Dipterex® (dimethyl 2,2,2-trichloro-1-hydroxyethyl phosphonate). The insecticides were administered by stomach tube, by feeding, and by intramuscular injection. For 7 days until sacrifice, the horses were observed frequently and checked for whole blood cholinesterase activity. Although six of the animals showed signs of toxicity during the observation period, only one showed gastrointestinal congestion at necropsy. Fourteen horses owned by cooperating ranchers were treated with Dipterex in feed, with no harmful effect. The problems of determining poisoning from phosphorus insecticides are discussed.

Toxicity to House Fly Larvae of Droppings from Chickens Fed Insecticide-Treated Rations1

The toxicity to house fly (Musca domestica L.) larvae of feces from chickens on a continuous dietary regimen of laying ration containing- Co-Ral® ( O -(3-chloro-4-methylumbelliferone) O, O - diethyl phosphorothioate), Diazinon® ( O,O -diethyl O -(2-iso- propyl-4-methyl-6-pyrimidinyl) phosphorothioate), Dipterex® ( O,O -dimethyl 2,2,2-trichloro-1-hydroxyethylphosphonate), malathion, phenothiazine ronnel , and Dow ET-15 ( O -methyl O -(2,4,5-trichloropenyl) phosphoramidothioate) was investigated. The insecticide levels in the feed that caused greater than 90% mortality in larvae placed in the manure were: Co-Ral, 89 p.p.m.; Diazinon, 154 p.p.m.; Dipterex, 89-132 p.p.m.; ronnel, 176-220 p.p.m.; and Dow ET-15, 89 p.p.m. Feces from chickens on malathion- and phenothiazine-treated rations caused relatively low mortality in the larvae at concentrations as great as 1,102 p.p.m. and 11,023 p.p.m., respectively.

A Study of the Histological Effects of Hypoderma lineatum (De Vill.) on Gullet Tissue Taken from Systemically Treated and Untreated Cattle

An evaluation was made of the histopathological effects of the systemic insecticide, O -(3-chloro-4 methylumbelliferone) O,O -diethyl phosphorothioate (Co-Ral®; Bayer 21/199), on the gullet tissues of cattle sprayed with a 0.5% concentration and cattle drenched at the rate of 10 mg./kg. body weight for control of the common cattle grub (Hypoderma lineatum (De Vill.)). Good control of grubs with the spray and none with the drench resulted. A study of the prepared sections revealed no difference in the actual tissue of the grubs, except in case of the dead grubs. An examination of the gullet connective tissue surrounding the grubs revealed the following: Tissue from Sprayed Animal: Tissue and cells appear to be normal, i.e. normal numbers of macrophages, lymphocytes, plasma cells, and fiberblasts, and collagen ous fibers, The spray apparently had no effect on the connective tissue around the parasites or on the walls of the esophagus. The esophagi from the sprayed animals were normal. Tissue from Drenched Animal: Very heavy infiltration of lymphocytes, macrophages, and plasma cells, and fiberblasts, with active inflammation was observed. In the submucosa, loose and reticular connective tissue fibers were normal. Quite a number of plasma cells and macrophages were present. Many polymorphoneuclearcytes were present, indicating active inflammation probably owing to drench. Also noticeable was a mild to acute inflammation of the connective tissue fibers and cells of the lamina propriety of the esophagus. The inflammation was doubtless caused by the reaction of the host to one or two foreign agents, namely, the larval stages of H. lineatum , and the administration of the systemic insecticide. This probably indicates that the use of Co-Ral as a drench not only failed to give grub control, but was detrimental as well.

The in vivo Activity of Several Systemic Insecticides against Cattle Grubs in South Dakota1

Data are presented on the activity of several successful and unsuccessful materials for systemic control of cattle grubs, Hypoderma lineatum (De Vill.) and H. bovis (L.). Rounel, applied as drench or bolus at approximately 110 mg./kg., proved highly effective (99% or better) except where infestation levels averaged less than one grub per head. Dimethoate, oral as well as intramuscular at 15 mg./kg., was highly effective (94%) but was accompanied by depression (as much as 56%) of cholinesterase activity coupled with at least initial weight gain deceleration. Dowco 109 ( O -(4- tert -butyl-2-chlorophenyl) O -methyl methylphosphoramidothioate) when sprayed at a concentration of 0.75% proved highly effective (100%) and was accompanied by no detectable cholinesterase depression, but when sprayed at 0.5% over the entire body or on the backs of cattle alone, this material failed or gave marginal control (27%-76%). Bayer 21/199 ( O -(3-chloro-4-methylumbelliferone) O,O -diethyl phosphorothioate, as wettable powder or as emulsion, was sprayed at 0.5% and at 0.25% under conditions of complete or partial coverage of cattle. The results with this material (at 0.5%) show considerable irregularity, ranging from excellent (91% to 97%) to poor (under 65%) but not directly correlated with formulation or degree of coverage. The tests at 0.25% concentration failed (43% control or less). Nicarbazin (complex of 4,4'- dinitrocarbanilide and 2-hydroxy-4,6-dimethyl pyrimidine), provided as a multiple oral dosage of 25 mg./kg., was unsuccessful (26%), but when administered as single oral dosages at 125 mg./kg. was successful though poor (65%), and at 250 mg./kg. was moderately successful (86%). Six other materials, each of which had shown promise in in vitro tests, were unsuccessful (27% control or less); these materials are: (I) 9-amino-6-chloro- 2-methoxyaeridine; (II) 4,4' dimethylbenzhydryl amine HCl; (III) di-n-butyl tin dilaurate; (IV) I-phenyl-3-(5-nitro-2-thia zolyl) urea; (V) 2-(p-nitrobenzamido)-5-nitrothiazole; and Monacrin®, 9-aminoacridine HCl. The data presented on gains in weight do not provide evidence of a relationship between grub control and weight-gaining ability of calves maintained under dry-lot conditions. In general, the degree of grub control obtained appeared better in experiments involving heavily infested cattle than in lightly infested animals.