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An alternative method for the confirmation of heptachlor residue identity is described. This method entails derivation in a solid matrix prepared from alumina and sulfuric acid to obtain a single derivative in almost quantitative yield.

Netted Gem potato plants infected with either the ring rot bacterium (Corynebacterium sepedonicum) or the potato leaf roll virus alone exhibited typical symptoms of the respective diseases. Plants infected with both the bacterium and the virus exhibited severe leaf roll. Typical ring rot symptoms were masked in dual infections, thereby increasing the difficulty in detection of the bacterial disease. The combined yield-reducing effect of the two pathogens was greater than that of the potato leaf roll virus and was similar to that caused by ring rot alone.

Insecticide assays using larvae of Cryptophlebia leucotreta Meyrick (Lepidoptera: Tortricidae; subfamily Olethreutinae) showed that parathion-methyl and monocrotophos were more toxic than fenitrothion and endosulfan. The LD90 were 3.44 mg/kg and 11.0 mg/kg for parathion-methyl and monocrotophos, respectively. The order of relative efficiency of the insecticides was as follows: parathion-methyl, monocrotophos, fenitrothion and lastly endosulfan. When different spray machines were tested for spray deposition on well grown cotton plants, the motorised airblast sprayer effected a more satisfactory deposit recovery on the lower parts of the cotton plants where early and heavy infestation of C. leucotreta to the mature cotton bolls occurs.

SummaryResults are given of field trials in which various chemical sprays were tested for control of the strawberry mite Tarsonemus fragariae. Activity of most compounds was poor, although promising results were obtained with Bayer 5024 (methiocarb), Boots BTS 27419, Du Pont 1642 and Shell WL 21959 (‘Talcord’). None gave as good control as a standard endosulfan spray, but some results were better than those achieved with a standard application of dicofol.

Two isomeric 10,10-dihydro-endosulfans are isolated, and their configurations are determined by means of infrared and nuclear magnetic resonance spectra. The isomerisation of the sulfurous ester ring of 10,10-dihydro-endosulfan yields a 67/33 ratio for the α/β isomers, while the endosulfan gives a 45/55 ratio. Both the 10,10-dihydro-endosulfans prove to be less easily hydrolised than endosulfan.

Trials to determine if the costs of eradicating G. morsitans by aerial application of endosulfan (Park et al 1972) might be reduced, were carried out using lower quantities of the pesticide. Area dose rates were varied by altering; the swath width, the insecticide output per unit flying time and the insecticide concentration. The trials were judged by the reduction of the adult tsetse population after a single application. Results indicated that eradication of G. m. morsitans under the conditions prevailing in N.W. Botswana, is possible by the repeated application, at 21 day intervals, of 20% endosulfan at 3.0 //km2 (0.6 kg a.i./km2). Applications should be made at a swath interval of 274m, using a single AU 3000 Britten-Norman Micronair unit to produce spray droplets mostly smaller than 40μm diam. The cost (1973) of each application (aircraft and insecticide only) was approximately US $13.00/km2 for an area in excess of 1000 km2.

In field-scale and small-plot trials conducted during 1972–73 green peach-potato aphid was not controlled by excessive rates of oxydemeton-methyl, demeton-S-methyl, parathion-methyl, omethoate, propoxur, and quinalphos. Endosulfan, methomyl, and dichlorvos also gave inadequate control. It is concluded that resistance is implicated in the failure of these insecticides. Acephate, BAY 6437, and methamidophos gave adequate control.

Porous polyurethane foams were used for the extraction and recovery of chlorinated insecticides and polychlorinated biphenyls (PCBs) from water. One litre of tap water was doped at the ppb 1 level and elution of the adsorbed compounds was complete with 50 ml of acetone and 100 ml of n -hexane. Quantitative recoveries were obtained for the thirteen insecticides used, at a water flow-rate of 100 ml/min. The recoveries for PCBs were 40–99% at 100 ml/min. The amount of methylene blue adsorbed from aqueous solution by the foams was correlated with the efficiencies of six foams, of different surface areas and bulk densities, for adsorbing chlorinated insecticides and PCBs from water.

Field trials at Pukekohe of insecticides against potato tuber moth (Phthorimaea operculella Zell.) showed that little direct control of tuber infestation was achieved. Foliage infestation, however, was effectively controlled; and this indirectly effected a reduction in tuber infestation, as long as nearby areas were also clean. Although both recommended insecticides, azinphos ethyl and endosulfan, were effective against foliage mining under low to moderate population pressure, only azinphos ethyl was consistently effective under high to extreme pressure. Four additional candidate insecticides (ENT 27041, acephate. methamidophos, and chlorpyrifos) were compared with azinphos ethyl, but none proved as good, although acephate showed some promise. The standard aphicide oxydemeton methyl was found to have a small but significant effect on the foliage-mining population. It was found that 4.8% of infested tubers escaped detection at harvest grading because young mines and eggs are not easily seen. As a ...

Two field trials were done in Uganda in 1968 to study the influence of soil fertility (levels of nitrogen and phosphorous fertilizer) on the damage caused by Chilo zonellus (Swinhoe) to grain sorghum by comparing treated (endosulfan) and borer-infested plots. The number of sorghum heads and the plant height increased with increasing amounts of fertilizer, but borers decreased both of these measurements. Also, phosphorous fertilizer tended to shorten the flowering period, but nitrogen fertilizer and borers extended it. Stand and number of stalks were not influenced by borers, perhaps because the infestation came late in the season, but there were about 3 times as many seedless heads in infested plots as in treated plots. More borers per plot were found when phosphorous fertilizer was used. Both fertilizers contributed to increased yield of grain, but borers prevented a maximum response to soil fertility.

Bidrin® (3-hydroxy- N, N -dimethyl- cis -croton-amide dimethyl phosphate), Monsanto 40294 ( O-p -nitrophenyl 0 -phenyl methylphosphonothioate), Bayer 25141 ( O, O -dieliethyl O-p - (methylsulfinyl) phenyl phosphorothioate), Guthion® ( O, O -elimethyl S- (4-oxo-I,2,3-benzotriazin-3 (4- H )-ylmethyl) phosphorodithioate) and carbaryl were the most effective compounds for control of the cowpea curculio, Chalcodermus aeneus Boheman, on southernpeas. Toxaphene was variable in effectiveness. Bidrin, Monsanto 40294 and Bayer 25141 were the most effective compounds for control of the leafminer Liriomyza munda Frick. No differences were found between 2, 4, and 7 applications of carbaryl for cowpea curculio control. No differences were found between 2 and 7 applications of Guthion for cowpea curculio control. Bidrin increased in control as the number of applications were increased to 7. Seven applications of Bidrin. Guthion, and carbaryl were superior to 1–4 applications for control of the corn earworm, Heliothis zea (Boddie). Four applications of Bidrin increased corn earworm control over 1–3 applications while no significant differences were found between 1–4 applications of Guthion and carbaryl. Oil-toxaphene and -endosulfan combinations varied in effectiveness for cowpea curculio and leafminer control in 2 experiments, Penetrant NS-139 increased the effectiveness of bidrin as a leafminer toxicant and to a lesser degree a toxicant against the cowpea curculio.

Endosulfan residues on alfalfa hay exposed to drying by sunlight, ultraviolet light and air under controlled conditions were investigated using g.l.c. and t.l.c. Maximum loss of total endosulfan and related residues calculated as endosulfan occurred approximately 7 days after application and exposure on Lot 1 (dark) and 5 days on Lot II (ultraviolet light) and 6 days on Lot III (sunlight). Maximum losses of residues on Lot I, Lot II and Lot HI were 48.3, 66.7 and 81.9%, respectively. No endosulfan lactone was detected in any of the samples exposed to the different light treatments. In all Lots the endosulfan sulphate percentage of the total residue increased but most dramatically in the dark drying experiment. The endosulfan a-hydroxy ether residues increased in Lot III (sunlight) up to day 7.

Endosulfan was effective in several experiments in 1965-67 against Phylloxera vitifoliae (Fitch) attacking the leaves of grape cultivars. Marechal Foch, 'Seibel 7053', and 'Seibel 5279' in Ontario. It was slightly more effective applied in the postbloom than in the prebloom spray, and less effective when applied soon after the beginning of shoot growth. Lindane also was effective as a summer spray, but dimethoate was not effective. A preliminary leaf-dipping test showed several other insecticides were not promising as foliar treatments. Dormant applications of Morestan® (6-methyl 2,3-quinoxalinedithiol cyclic S,S -dithiocarbonate), Ethion Superior oil, and lime sulfur reduced phylloxera injury to 'Clinton' grapes, but were less effective than summer sprays.

Following a season of extensive damage to the commercial sweet corn crop, producers on Long Island became alarmed at the possibility that the corn earworm, Heliothis zea (Boddie), had become resistant to DDT. Experiments conducted during the next three seasons dispelled this view. Sevin® (1-naphthyl-N-methyl carbamate), used at equivalent rates, was shown to be as effective as DDT. Endrin, Thiodan® (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide), Guthion® ( O,O -dimethyl S-(4-oxo-3H-l,2,3- benzotriazine-3-methyl) phosphorodithioate), and Shell 4402 (1,3,4,5,6,7,8-octaehloro-3a,4,7,7a-tetrahydro-4,7-methanophthalan) gave promising results at the dosages used. In addition, endrin, DDT, Guthion, Phosdrin® (1-methoxycarbonyl-lpropen-2-yl dimethyl phosphate), and ryania were found to reduce considerably ear damage caused by the European corn borer, Pyrausta nubilalis (Hbn.). Thiodan was partially effective. Analyses of corn samples revealed the absence of DDT and the presence of insignificant residues of Sevin on the husked ear. Experiments conducted concurrently with the aforementioned tests revealed that the addition of various surface-active supplements to DDT sprays apparently had little or no effect in enhancing or prolonging the effectiveness of the sprays with the possible exception of Atlas NNO which, in one test, seemed to improve control.

The control of larvae of the cabbage looper, Trichoplusia ni, and the imported cabbageworm, Pieris rapae, by viruses, bacteria, and chemical insecticides was compared. In small field plots five applications of the nuclear-polyhedrosis virus of T. ni (1.8 × 1011 polyhedra/acre) and the granulosis virus of P. rapae (4 ×1011 granules/acre) controlled the respective host larvae as well as five applications of the chemical insecticide methomyl (0.5 to 1 lb/acre). Dipel HD-1 (0.25 lb/acre) and Thuricide HPC (60 fl. oz/acre), formulations of Bacillus thuringiensis, were as effective against T. ni larvae as methomyl but not as effective as Fundal (0.5 lb/acre) or Dipel at a higher rate (0.5 lb/acre). The control obtained by combinations of viruses with endosulfan or methomyl suggested an effective method of reducing use of chemical insecticides. Control of T. ni and P. rapae in plots up to 3 acres in area in growers’ fields demonstrated the effectiveness of the viruses when used as commercial insecticides.

Results are reported of residues of α- and ,β-endosulfan and endosulfan sulphate on tomatoes, potatoes, cabbages, and cauliflowers UI)der New Zealand conditions. Residues are shown to be below 2 ppm on these crops after the following waiting periods: tomatoes—2 days; potatoes—none; cabbages and cauliflowers—4 weeks. The period for tomatoes could be reduced to 1 day or less if skins were removed in processing; and for cabbages and caulifiowers to I to 2 weeks if fully trimmed of loose outer leaves. The latter treatment appears to require definition for regulatory purposes.

Endosulfan is a worldwide used synthetic insecticide that has an important role on management of pests in agriculture. The present work was undertaken to determine the effect of endosulfan on the haematological and haemochemical parameters of albino rats. Rats were feed with 5 mg/kg body weight endosulfan in mixed food stuff for 42 days. The studies were conducted on sexually matured male rats covering five groups of animals with control. Total counts of erythrocytes and haemoglobin were decreased and leucocytes were increased in treated group. Differential counts of leucocytes showed significant increase in basophils and monocytes. The levels of serum glucose, urea, creatinine and bilirubin increased significantly, suggesting that the synthetic insecticide had remarkable toxic effects on the haematological and biochemical parameters in the experimental animals. Key words: Endosulfan; prolonged exposure; haematology; haemochemical parameters; albino rat DOI: 10.3329/jles.v5i0.7346 J. Life Earth Sci., Vol. 5: 29-32, 2010

Several new pesticides and combinations thereof were applied to table beet seed plants and to carrot seed plants in performance trials against the lygus bug, Lygus hesperus Knight. Six pesticides were tested: DDT, ethion, Dylox® (dimethyl 2,2,2-trichloro-l-hydroxyethylphosphonate), Thiodan® (6,7,8,9,10,10- hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin- 3-oxide), Trithion® (S-(p-chlorophenylthio) methyl O,O -diethyl phosphorodithioate), and Di-Syston® ( O,O -diethyl S -2-(ethylthio) ethyl phosphorodithioate). These were used alone or in combinations. The natural population in small plots was augmented by three introductions resulting in an accumulated high of 23.5 bugs per plant during the tests. The trials on beets involved single sprays for eight plots; and a series of five applications for two plots. A spray containing DDT plus Dylox gave the most complete control of lygus bugs, or 78% control during a 28-day period. Thiodan plus Dylox was almost equally good. Five sprays of Di-Syston and five dustings with DDT plus Trithion, and single sprays of DDT plus Trithion or DDT alone ranked in the midrange of observed values, or 56% or 62% control. Thiodan or ethion, alone or in combination, were the least effective. All applications containing Thiodan as well as the one containing DDT plus Dylox were appreciably more toxic to the pirate bug, Orius tristicolor White, than the other test materials. DDT plus Dylox spray had no perceptible effect on ladybeetles, Hippodamia spp. but sprays containing Di-Syston (5 applications) or ethion drastically reduced their numbers. DDT plus Trithion dust (5 applications) resulted in a significant increase in numbers of aphids and ladybeetles. The five Di-Syston sprays afforded a significant reduction in the number of plants infected by beet mosaic, and reduced the grade of infection. The best treatments for control of lygus bugs also increased the average size and viability of beet seed. All but one of the treatments increased the average yield of seed per plant. Dusts applied twice by aircraft to control lygus bugs in seed carrots were, in descending order of value for lygus bug control: 10% DDT plus 5% Dylox, 3% Thiodan, 10% DDT plus 2% Trithion, and 10% DDT. Seed yield was significantly increased in third-stage seed heads by the DDT plus Trithion dust. Increa sed yield for fourth-stage seed heads was obtained only from plants dusted with DDT plus Dylox, the only treatment that gave very significant increases in seed size for seeds threshed from third- and fourth-stage seed heads.

Endosulfan, oxydemetonmethyl, and endrin applied in sprays at 1 lb per acre to Russet Burbank potatoes were equally effective in the control of the green peach aphid, Myzus persicae (Sulzer). The incidence of leaf roll in growing plants was reduced significantly when spray applications were continued until mid-June. Also 4 applications ending in late June reduced net necrosis in the tubers and chronic leaf roll in stocks replanted the next season. Net necrosis was a less reliable index than chronic leaf roll for determining the effectiveness of insecticides in suppressing leaf roll. Chronic leaf roll developed in 96, 30, and 18% of plants grown from tubers that contained net necrosis, other discolorations, and no discolorations, respectively.

Hippelates gnats breed predominantly in loose, cultivated soils, and one approach to their control is through soil treatments. The effectiveness of aldrin and other soil insecticides was investigated in the field. Aldrin and heptachlor sprays and granules within the range of practical dosages produced moderate initial control of Hippelates gnats but gave no significant reduction in gnat breeding after a lapse of 7 to 10 months. Dieldrin was not tested for its initial effectiveness, but at moderate dosages gave no control of gnats 7 months after application. Thiodan® (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9- methano-2,4,3-benzodioxathiepin-3-oxide) at the highest applied dosage (6.2 lbs. per acre) was ineffective, and results with toxaphene were inconclusive. DDT was the only insecticide among the materials tested that gave a high degree of initial control of Hippelates collusor (Townsend). This material, when applied at 13 pounds actual toxicant per acre, gave 95% reduction of the emerging gnats initially. The long-term residual effectiveness of this material is not yet known.

Systemic insecticides were applied to the soil on each side of potato seed pieces at planting time and/or were sidedressed into the soil when 75% of the plants emerged, and multiple foliar sprays were applied to obtain seasonal control of Myzus persicae (Sulzer) and the suppression of potato leaf roll virus on ‘Russet Burbank’ potatoes in eastern Washington. Aldicarb gave superior control of aphids and suppressed spread of the virus; disulfoton gave fair control of aphids, but not much suppression of potato leaf roll virus; and phorate did not give sufficient control of aphids or the disease. The 2 applications of the systemic insecticides were more effective than either single application. Endosulfan and oxydemetonmethyl as foliar sprays (2-5 applications) gave better control of aphids than demeton and disulfoton but none significantly suppressed spread of the virus. All applications of systemic insecticides in combination with multiple applications of foliar spray gave significant control of aphids, and most treatments significantly suppressed the spread of disease.

Summary In an unreplicated field experiment using areas 5 acres and larger for each treatment, 15 lb of toxaphene per acre in 3 applications, applied to white clover in flower, increased seed yields approximately 5 times and reduced seed damage caused by Coleophora spp. from 29.7% to 12.1%. In laboratory tests, toxaphene and strobane at 10 lb/ac equivalent did not cause significant mortality in fin il instar larvae of Coleophora alcyonipennella? Kollar after 48 hours exposure. Under the same conditions, thiodan at 5 lb/ac equivalent caused 60% larval mortality. Toxaphene and strobane are apparently highly toxic only to adults of Coleophora species; these materials may be used while clover is in flower with minimum risk of toxicity to honey bees. Thiodan may be toxic to honey bees when used on flowering crops. Further trials using toxaphene and strobane appear warranted.

The toxicity of a variety of pesticides to the stigmaeid mite predator Agistemus fieschneri Summers was studied in laboratory and field experiments. Results indicated that predators were inherently tolerant to several organophosphate insecticides. Treatments of Dikar® [maneh (57.4%) + dinocap (4.7%)], dinocap, Plictran® (tricyclohexylhydroxytin), carbaryl, Omite® (2-( p-tert -butylphenoxy)cyclohexyl 2-propynyl sulfite), endosulfan, and phosalone were highly toxic to A. fieschneri . Tests indicated that several additional chemical treatments were intermediate to nontoxic to A. fieschneri and use of these materials in an integrated pest control program may allow predators to persist in apple orchards and provide biological control of destructive spider mite pests.

When endosulfan was applied at rates of 4, 8, and 16 oz/acre to forage crops, residues persisted through 71 days on grazed pastures of Coastal Bermudagrass. Fat of beef animals grazed 31–36 days on the treated pastures, beginning 7 days after treatment, were free of detectable residues. Endosulfan persisted in grass silage through 78 days. An unknown product of endosulfan which increased with time was found in silage and was later identified as endosulfan sulfate. Milk from dairy cows fed silage averaging 0.41, 0.70 and 2.35 ppm endosulfan for 21 days was free of detectable residues. Two beef animals ingesting endosulfan at the rate of 5.0 and 2.5 mg per kg per day showed symptoms of toxicity after 2 and 13 days, respectively. Detectable residues were found in fat from animals ingesting endosulfan at the rate of 1.10 mg per kg per day, but there were no signs of toxicity to the animals.

Results from a series of field experiments confirmed the effectiveness of carbaryl and lindane for control of the, Diaphania nitidatis (Stoll), on squash, cantaloupes, and cucumbers. Other materials found to be highly effective against this insect were endosulfan, GC 6506 (dimethyl p -(methylthio) phenyl phosphate), GS 13005 (O,O-dimcthyl phosphorodithioale S -ester with 4-(mercaptomethyl)-2-mcthoxy-∆2-1,3,4-thiadiazolin-5-one), and NIA 10242 (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) , applied weekly as foliar sprays. Fungicides significantly reduced pickleworm injury to cantaloupes and cucumbers. Seed treatments with systemic insecticides failed to control the pickleworm on squash. Repeated applications of insecticides at recommended and accelerated rates had no adverse effect on squash or cantaloupe yield.

New and standard insecticides were evaluated for control of the cabbage looper, Trichoplusia ni (Hubner), and imported cabbageworm, Pieris rupae (L.), on cole crops in field trials carried out at Geneva, N. Y., in 1966 and 1968. Of the standard insecticides recommended for looper control only a combination of parathion and endosulfan achieved satisfactory results when applied on a 7- to 10-day schedule. Methomyl, recently registered for control of lepidopterous pests on cole crops, also gave good control of the looper when tested on this application schedule. None of the standard insecticides gave satisfactory reduction in numbers of looper larvae when sampling was carried out after 1 and 2 applications were made following development of looper infestation in the trial plots, However, very promising reductions in the looper larval population were achieved when the newer materials methomyl, Monito® ( O,S -dimethyl phosphoramidothioate), and DuPont 1642 (methyl N -(carbamoyloxy) thioacetimidate) were applied in this type of program. All materials tested gave adequate control of the imported cabbageworm.

Invertebrates were removed from soil samples taken from 15 test plots (0.11-0.38 acre) in an irrigated pasture at Tucson, Arizona, treated 2 years previously with various insecticides. Tullgren funnel and benzene extraction procedures were utilized. Mites and Collembola represented 63 and 31%, respectively, of the invertebrates collected. Analysis of variance indicated no significant differences between plots in total counts of mites and Collembola. There were differences among the treatment means for the other arthropods. 80-90% (∼6700 of 7865 specimens) of the mites in the plots treated with endosulfan, endrin, and DDT were orihatids; those in the DDT-Strobane® (terpene polychlorinates (65% chlorine)) plot were 70-80% (∼350 of 466 specimens) mesostigmatids. Ground pearl ( Margarodes sp.) crawlers were obtained from all plots except that treated with Strobane-DDT. The malathion-Perthane (a mixture of 1,1-dichloro-2,2-his (p-ethylphenyl) ethane (95%) and related reaction products (5%)) plot yielded approximately 2000 more animals than any other, includiug the check plot. Predawn appears to be the best time for sampling of soil arthropods.

Light-trap catches of Heliothis armigera (Hb.) reach peaks during the wet seasons, April and November–January. Initial infestation of seed beans by H. armigera occurs in April–May at the time of flowering of the early-sown crop, the adults probably originating from an earlier generation on maize. Two generations are completed during the main seed bean season, the first on early-sown beans and the second on later beans, and the dry period July–October may be passed in pupal diapause. Damage, caused by the older larvae eating the seeds in the pod, is prevented by spraying the young larvae with DDT (25% e.c. at 3 pt/2 gal spray/acre) (the standard treatment) or endosulfan (35% e.c. at 1½ pt/2 gal spray/acre) at about six weeks after the beans emerge.Adults of the Pentatomid Nezara viridula (L.) invade bean fields from alternative host-plants at the same time as H. armigera. This species, even in small numbers, causes the loss of young pods and also damages or kills the developing seed. It is not controlled by the standard DDT treatment for H. armigera, but the following insecticides were found to be effective: γBHC 20% e.c. (1¼ pt), dieldrin 18% e.c. (2 pt) and endosulfan 35% e.c. (1½ pt) in 2 gal spray/acre. Where N. viridula and H. armigera are found together, the standard recommendation is endosulfan 35% e.c. (1½ pt/2 gal spray/acre).The Coreids Acanthomia horrida (Germ.) and A. tomentosicollis (Stål) cause damage similar to that of N. viridula, but are serious only when infestations are heavy. They were found to be controlled by DDT, dieldrin or endosulfan at the rates given above.Alatae of the bean aphis Aphis fabae Scop, invade bean fields mainly during the first two weeks of the crop, producing apterae which concentrate on the tip of the plants. Damage (stunting, and loss of flowers and pods) is serious only when large populations of apterae are produced on a high proportion of the young plants. The early infestation demands control measures separate from those for the other pests, the most effective being methyl-demeton 50% e.c. (½ pt/2 gal spray/acre) applied 3–4 weeks after emergence. Endosulfan, although promising and far less toxic than methyl-demeton to larvae of the predator Cheilomenes lunata (F.), was discarded on grounds of cost, as was dimethoate. Aphid populations reached a peak during July and August and decreased with the warmer weather in September. A large number of alternative host-plants is listed, but the source of the primary flight into beans is not known.Melanagromyza phaseoli (Tryon), the life-cycle of which is completed in 23 days, is unimportant on seed beans as it is least abundant during the growing period of the main crop, but may damage plants suffering from water stress. Tunnelling in stems by larvae was controlled by seed dressings of aldrin or heptachlor (both 40% wettable powders mixed with seed at 1:200 w/w).

Gas chromatography was used for chemical analysis of amounts of chlorpyrifos and endosulfan reaching Musca domestica L. by vapor and spray. The dose-toxicity data obtained by these methods of treatment were analyzed by the probit method. The LD50 values thus derived were compared with those of topical applications of known concentrations, LD50 values for chlorpyrifos, in ng/female fly, were: 43±6.5, 57±27, 35±7.5, and 46.8±10.5, for topical, spray, vapor, (Experiment 1), and vapor (Experiment 2) treatments, respectively. Experiments with endosulfan gave LD50 values of 167±20, 216±30, and 143±47 ng/female for topical, spray, and vapor applications, respectively. These LD50, values obtained from different methods of delivery were not statistically different based on the overlapping of their confidence limits. They show that the toxicity of externally administered chlorpyrifos and endosulfan is not significantly influenced by differences in external methods of delivery. If true for all insecticides then the optimum spray droplet size for any target insect can be calculated from physical parameters related to diffusion and impingement.

Field experiments on flue-cured tobacco were conducted in North Carolina during 1964--69 to determine the effects of certain treatment variables on control of Heliothis virescens (F.) with insecticides applied mechanically. No significant differences in crop protection were found among (I) treatments of 0.75 pounds per acre of endosulfan and 1.5 pounds of carbaryl, DDT, and TDE; (2) 0.75-, 1.5-, and 3.0-pound rates of TDE; (3) wettable powder, emulsifiable concentrate, ultra-low volume, dust, and bait formulations of TDE; (4) electrostatic and conventional applications of TDE spray and dust, and (5) times of the day when TDE was applied. Significant differences in protection were found with respect to (I) the volume (4 vs. 100 gallons per acre) of TDE spray used, (2) the pressure (5 vs. 150 pounds per square inch) at which TDE spray was applied. (3) the spray angle (15 vs. 55°) used to apply TDE, and (4) the age (2 VS. 7 days) of larvae at the time TDE was applied. Better protection was obtained when applications were directed against 2-day-old larvae, and high volume, high pressure, or narrow spray angle increased this protection. However, protection with the better combinations of volume, pressure, and spray angle seldom exceeded 66%.

The procedures involve the removal of captafol, captan or endosulfan spray deposits from the plant surfaces with solvent and their measurement by g.1.c. In contrast to residue analysis, clean-up procedures are avoided and the speed of the methods enable large numbers of samples to be processed in the monitoring of initial spray deposits and the subsequent redistribution or loss in relation to the efficiency of spray application techniques. Recoveries of captafol and captan suspension deposits from glass were greater than 96%: recoveries of emulsion deposits from plant surfaces were greater than 95 % for captafol, 93 % for captan and 96 % for endosulfan.

The pesticides Aldrin, Dieldrin, Endrin, Parathion, Baygon, Malathion, Dalf, Rogor, Metasystox, Sevin and Thiodan were isolated from human viscera by direct extraction with solvents or by steam distillation followed by solvent extraction of the distillate. When necessary, the extracts were passed through a column containing adsorbents for further purification. The resulting concentrated solutions were subjected to thin-layer chromatography and the spots identified by suitable spray reagents.

1. 1. Reduction of dietary protein to one-third optimal intake lowered the growth rate but has little effect on the LD50. 2. 2. Rats fed one-seventh optimal intake did not grow and were particularly susceptible to carbaryl and captan toxicity. 3. 3. Rats fed 0 per cent casein lost weight and were more susceptible to all the tested pesticides but particularly so to monuron and lindane (12 times), endosulfan (20 times), and captan (2100 times).

Burley tobacco harvested immediately after treatment with 0.5 Ib/acre of endosulfan and cured for four months contained average total endosulfan residues of 23.2 ppm. Residue levels in the top, middle, and bottom leaves were 49.6, 13.2, and 6.7 ppm, respectively. On the top leaves, endosulfan I comprised 13 percent, endosulfan II 78 percent and endosulfan sulfate 9 percent of the total. The sulfate accounted for approximately 20 percent of the total residues on the middle and bottom leaves, with a corresponding decrease in the concentration of endosulfan II. When the time between treatment and harvest was increased to 28 days, the average total residues on the cured tobacco was 2.2 ppm, with almost equal quantities on top, middle, and bottom leaves. Treatment at 42 and 70 days prior to harvest resulted in 0.64 and 0.34 ppm total residues and 1.15 and 0.41 ppm highest residues in the bottom leaves. Comparing the levels of residues in freshly harvested tobacco with those in cured tobacco showed that the loss during curing decreased as the time between treatment and harvest increased to 14 days (53 percent loss), but remained constant thereafter.

Tests were conducted to determine the effectiveness of 9 insecticides for control of Homoeosoma electellum (Hulst). Tests at College Station, Texas, showed that 2 applications of methyl parathion, endosulfan, diazinon, and malathion reduced the number of larvae and increased yields. Tests at McGregor, Texas, showed that only endosulfan and carbaryl reduced the larval infestation following 1 application; however, they did not increase yields. Two applications of GS-13005, (O,O -dimethyl phosphorodithioate Sester with 4-(mercaptomethyl)-2-methoxy-∆2-1,3,4-thiadiazolin-5-one), azinphosmethyl, methyl parathion, carbaryl, azinphosmethyl ultra-low-volume (ULV) and methyl parathion ULV increased yields. Plots treated 3 times, except those treated with malathion ULV, had lower infestations than the check plots and yields were increased except when treated with trichlorfon. Yields were significantly increased when methyl parathion, endosulfan, or carbaryl were applied at 5-day intervals. Applications at pre-flower, or at 10% flower, in most cases, did not significantly reduce the number of larvae or increase seed yields. Generally, insecticides applied at the 50 and 100% flower stages were most effective.

Test materials applied to control Trialeurodes vaporariorum (Westwood) in greenhouses varied in their toxicity to nymphs and pupae. Aldicarb was more effective than other systemic insecticides tested. Sprays of parathion gave higher kills and had longer residual activity than aerosols. Sprays of azinphosmethyl and monotocrotophos were equal to parathion in controlling nymphs. Endosulfan, which had previously given good control of whitefly nymphs, was relatively ineffective. Sprays were the most effective formulations, but aerosols, mists, or fumigants are easier to use in large commercial greenhouses. Also, the highly effective slow-release formulation of dichlorvos in ground corncobs may be acceptable for use in smaller greenhouses. Regularly timed applications of calcium cyanide as a fumigant or of aerosols or mists containing parathion, tepp, or dichlorvos were highly effective.

Field studies on timing of application and effectiveness of materials against Epitremerus pyri (Nalepa) were conducted during 1966 and 1967 in southern Oregon pear orchards. The degree of fruit russet increased with the time the trees were left unsprayed. Delayed dormant or pink bud applications of endosulfan resulted in an absence of economic injury at harvest, but when treatment was delayed until Mayor later, severe fruit injury was evident. Oil used alone or oil-organophosphate combinations applied prebloom effectively suppressed rust mite densities. Other materials found effective included: Carzol® (N′- (chloro-0-tolyl) -N, N- dimethyIformamidine hydrochloride). dimethoate, carbofuran, maneb, Morestan ® (6-methyl-2,3-quinoxalinedithiol cyclic S, S -dithiocarbonate), Temik® (a 10% granular formulation of UC-21149 (2-methyl-2-(methylthio) propionaldehyde 0 -(methylcarbamoyl) oxime) ), and zineb.

Five experiments were conducted during 1961 and 1962 to compare the toxicity of a variety of insecticidal sprays to larvae of the cabbage looper, Trichoplusia ni (Hubner); the beet armyworm, Spodoptera exigua (Hubner); and the diamondback moth, Plutella maculipennis (Curtis) on cabbage and cauliflower. The cabbage looper appeared to be effectively controlled by American Cyanamid 48064 (2-(diethoxyphosphinothiolimino)-1,3-dithio-lane), Bayer 44646 (4-dimethylamino- m -tolyl N -methylcarbamate), endosulfan, Monsanto 40273 ( O -propyl O -p-nitrophenyl methylphosphonothioate), Monsanto 40294 ( O -phenyl O -pnitrophenyl methylphosphonothioate), and Zectran® (4-dimethylamino-3,5-xylyl methylcarbamate). In general, beet armyworms and diamondback moth larvae were more readily controlled by insecticides than were cabbage loopers.