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Wastewater-based epidemiology is an innovative approach to estimate a population's intentional and unintentional consumption of chemicals based on biomarker assays found in wastewater. This method can provide real-time objective information on the xenobiotics to which a population is directly or indirectly exposed. This approach has already been used to assess the population exposure to four classes of pesticides: organochlorines (chlordecone), triazines, organophosphates, and pyrethroids. This review aims to obtain the data (excretion rates) and characteristics (pesticide and metabolites stability, including in-sewer one) for other pesticides to broaden the scope of this new method. Excretion rates and stability descriptions for 14 pesticides, namely 2,4-D, aldrin, carbaryl, chlorobenzilate, dieldrin, diquat, ethion, glufosinate, glyphosate, folpet, malathion, parathion, penconazole, and tebuconazole, will be discussed in a practical framework.

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗ, The main objective of the present research was to determine the concentrations of the selected pesticides in muscle, liver and skin of common carp. Fish were sampled in two different seasons from fish pond which received previously treated slaughterhouse wastewater. Pesticides including etridiazole, chloroneb, trifluralin, propachlor, chlorothalonil, hexa-chlorocyclopentadiene, atrazine, simazine, alachlor, metribuzin, metolachlor, DCPA, cyanazine, chlorobenzilate, endrin aldehyde, cis permethrin and trans permethrin were determined by using a GS-MS method. Many of pesticides were not determined or determined in low concentrations. Propachlor was found in muscle, skin and liver. The recommended acceptable daily intake was higher in comparison with the estimated daily intake for examined pesticides via fish reared in treated slaughterhouse wastewater. It is very important to maintain the safety of the fresh fish produced in wastewater in order to ensure food safety and avoid health problems in humans.

A fast and efficient method was developed and validated for the determination of pesticides in mangos, which uses the QuEChERS citrate and gas chromatography–mass spectrometry (GC–MS) techniques. A detailed statistical analysis was performed to study the matrix effect. The calibration model using the method of weighted least squares is used in cases, where heteroscedasticity is observed. The matrix effect was observed for most studied compounds using analytical curves based on a spiked matrix. The limits of detection were 0.0025–0.01 mg kg−1, and the limits of quantification (LOQ) were 0.008–0.03 mg kg−1. The LOQ values were minor or equal to the established MRLs by major regulatory agencies in Brazil (ANVISA), the United States (US-EPA), and Europe (CE). The compounds showed acceptable recovery levels of 71–109% with a standard deviation less than 15%. The method was applied to determine pesticide residues in mango samples. For 12 samples, five compounds (chloroneb, propachlor, α-chlordane, chlorpyrifos, DCPA, chlorobenzilate, and trans-permethrin) were detected, with contents of 0.004–0.042 mg kg−1. For chloroneb, propachlor, and α-chlordane, the found concentrations were above the maximum permitted residue limit, according to data from the European Commission.

Various chemicals were tested in field trials for the control of the grape vine bud mite. Chlorobenzilate (Akar) 50% ec at 50 ml/100 i water and propoxur (Unden) 20 % ec at 125 ml/100 i water resulted in satisfactory control. The best results were obtained with three applications per season at 14 day intervals, starting at bud burst. At least 500 ml spray mixture per vine must be applied.

Citrus (Citrus unshiu) peel extracts were utilized to develop a drink using a mixture design and optimization process. The contents of narirutin and hesperidin in the citrus peel extracts, as determined by high-performance liquid chromatography, were 10.25 and 7.65 mg/g, respectively. Residual pesticides in the citrus peel, such as chlorobenzilate, diethofencarb, malathion, methiocarb and carbaryl, were not detected. Heavy metals, including lead (Pb) and cadmium (Cd), were determined as 16.00 and 6.55 µg/g prior to washing the citrus peels, and 5.83 and 5.83 µg/g after washing, respectively. Development of the drink with citrus peel extract was carried out using fructo-oligosaccharide syrup and water. The interaction effects of these ingredients were investigated using a modified distance-based design and analyzed by linear regression models, nonlinear regression models and trace plots. Optimization of the mixture ratio was determined with statistical modeling using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, total flavonoid content and taste tests, all of which are important target constraints in a drink. Every constraint demonstrated a nonlinear canonical form. The response trace plot revealed that DPPH radical scavenging activity, total flavonoid content and taste tests were quite sensitive to citrus peel extract content in the drink. The optimal formulation of the drink was set at 1.974% citrus peel extract, 27.543% fructo-oligosaccharide syrup and 70.364% water. PRACTICAL APPLICATIONS Citrus peels extract can be utilized to functional drinks having a narirutin and hesperidin. Mixture design and optimization process enables us to attain the optimal mixture ratio with drink ingredients for the drink. Numerical optimization process can be effectively applied in other food mixture systems.

Gas chromatographic separation and identification of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCs) and chlorobenzenes (CBz) is one of the most common analyses performed by envir...

A liquid chromatography multi-residue method with photometric detection has been developed. The method is applicable to the quantitative deter- mination of organochlorine (tetradifon, dicofol, chlorfenson, chlorobenzilate), organophosphorus (fenitrothion, azinphos-ethyl) and carbamate (pirimicarb) pesticides in animal tissues. The extracted residues are cleaned up by gel- permeation chromatography. A further fractionation on silica Sep-Pack car- tridges is included in the procedure. A gas chromatographic method with electron-capture detection for the analysis of the same pesticides was carried out and the results in the two cases compared. Lower detection and quantitation limits and similar recoveries of pesticides from spiked pig liver and brain samples were obtained by the LC method.

In multiresidue analysis, as the complexity of matrix increases, matrix co-extractives might co-elute and interfere with the detection of target analytes, and thereby result in false positives and erroneous quantifications. This paper aims to evaluate the combination of enhanced mass resolution and concurrent selectivity and sensitivity in analyzing a complex mixture of 341 pesticides in grape, orange, tomato, okra and spinach by gas chromatography triple quadrupole mass spectrometry (GC-MS/MS). Timed-selective reaction monitoring (t-SRM) was found advantageous over segment SRM in terms of ease of method optimization and sensitivity. The optimized t-SRM method was used to test the applicability of ultra-SRM (USRM) in filtering out co-eluting interfering matrix compounds. False detections of benfluralin, dimethoate, etc. could be avoided when mass resolution was increased from 0.7 to 0.4 and 0.2Da (full width at half maximum). Similar observations were noted for chlorobenzilate, spiromesifen, tebuconazole, etc., in grape; omethoate, bendiocarb, monocrotophos, etc. in orange; omethoate, dimethoate, ethoxyquin, atrazine, etc., in tomato; and dichlobenil, omethoate, propoxur, monocrotophos, etc., in okra. The analysis at higher mass resolution could significantly minimize matrix effects (ME), e.g., 34% at 0.7Da for spiroxamine in grape to 0.6% (0.4Da) and -44% (0.7Da) for dichlorvos in okra to 8.8% (0.1Da). A feature called "quantitation enhanced data-dependent (QED) scan feature" was found effective in targeted screening to confirm the detection of atrazine, azoxystrobin, λ-cyhalothrin, etc. at trace quantities in incurred samples and avoid false detection of chlorpyrifos.

The Kenaga nomogram was developed by the U.S. Environmental Protection Agency (EPA) in the mid 1970s and has since been used prior to the registration of a pesticide to estimate the maximum potential pesticide residue level on plant material in the food chain of wildlife. The objective of this study was to evaluate the nomogram using field data. Six pesticides representing a variety of pesticide classes were applied to 15 plant species. Five of the six nomogram categories were tested with plant parts representing differences in surface morphology (i.e., glabrous vs. pubescent leaves). The sixth category was a mixed-grass community seeded with three grass species. Pesticide residue levels were determined the day of application and up to 32 d afterward. While the linear nomogram model does not represent the data as well as other models, relatively few data points (10%) collected on the day of pesticide application exceeded the nomogram predictions. The one systemic pesticide tested had degradation rates similar to nonsystemic pesticides in most categories. Present nomogram categories were significantly different from each other in most cases. However, the forage category should be combined with the leaves and leafy-crop category and have higher estimated residue levels than the Kenaga nomogram. A considerable amount of variation occurs in the level of pesticide residue on plant materials even under controlled experimental conditions and therefore nomogram values should be used as an estimate only until actual field residue data are available. The nomogram, with modifications, appears to be a reasonable regulatory device if careful thought is given in selecting the plant category for making residue estimates.

The potential hepatocarcinogenicity of seven pesticides was examined using a rapid bioassay based on the induction of glutathione S-transferase placental form positive foci in the rat liver. Rats were initially injected with diethylnitrosamine and two weeks later were fed on diet supplemented with one of the pesticides for 6 weeks and then killed; all rats were subjected to a partial hepatectomy at week 3. Positive results were seen with chlorobenzilate (2000 ppm), vinclozolin (2000 ppm), malathion (4000 ppm), tecnazene (2000 ppm) and isoproturon (2000 ppm). S,S,S-tributylphosphorotrithioate (DEF, 200 ppm) and dicloran (2000 ppm) were negative in both number and area analyses. Although chlorobenzilate is carcinogenic in mice, malathion and vinclozolin have been reported as non-carcinogens in both rats and mice. Since the present system is based on the two-stage carcinogenesis hypothesis, it is possible that the chemicals showing positive results in this system possess at least tumor-promoting activity in the rat liver. This is very significant, as most carcinogens show tumor-promoting activity in their target organs.

Three diphenylcarbinol acaricides (dicofol, chlorobenzilate, and bromopropylate) and three structurally related diphenylethane insecticides (p,p′-DDT, o,p′-DDT, and methoxychlor) were evaluated as inhibitors of octopamine-stimulated adenylate cyclase activity in membrane preparations from whole homogenates of two-spotted mites (Tetranychus urticae Koch). In survey experiments, a high concentration (100 μM) of each of the three diphenylcarbinols produced complete or almost complete inhibition of the octopamine-stimulated component of adenylate cyclase activity, whereas the three diphenylethanes had no significant effect when assayed at the same concentration. Dicofol, chlorobenzilate, and bromopropylate each gave biphasic concentration-effect curves for the inhibition of octopamine-stimulated adenylate cyclase activity having a sensitive component of inhibition detectable between 0.01 and 0.1 μM, a plateau at approximately 20 to 30% inhibition in the concentration range of 0.1 to 1 μM, and a less sensitive component of inhibition evident between 1 and 100 μM. Concentrations of dicofol that produced complete inhibition of octopamine-stimulated adenylate cyclase activity had no effect on forskolin-stimulated adenylate cyclase activity. Membrane preparations isolated from a strain of mites exhibiting resistance to diphenylcarbinols and cross-resistance to amitraz showed unaltered sensitivity to amitraz as a stimulator of adenylate cyclase activity and to dicofol as an inhibitor of octopamine-stimulated adenylate cyclase activity. These results identify a novel action of diphenylcarbinol acaricides that does not extend to structurally related diphenylethane insecticides and suggest that the octopamine receptor-adenylate cyclase signal transduction pathway may be an important target site for diphenylcarbinols.

Two kinds of measurement: (1) enzyme activities in blood, and (2) unchanged pesticides and their metabolites in urine or blood have been used in biological monitoring for assessing exposure to pesticides. The assays of acetylcholinesterase (AChE) activity in whole blood and erythrocytes are mainly applied to estimate inhibition by organophosphates (OPs) and carbamates. A level at 70% of an individual's baseline or of a mean population AChE activity has been recommended as a reference value for exposure control. The measurement of lymphocyte “neuropathy target esterase (NTE)” activity in subjects handling axonopathic OPs is mainly for research application. Analytical methods are available for detecting alkylphosphates, carbamates, pyrethroids, chlorinated hydrocarbons, some herbicides and fungicides, chlordimeform, chlorobenzilate, dichloropropene, dinitrocresol and pentochlorophenol or their metabolites in urine or blood. However, due to lack of significant dose-response or dose-effect relationship, the majority of these determinatants can only be used as biological exposure indicators to confirm exposure or to estimate internal dose. Further research in developing adequate indicators and methods for biological monitoring of occupational pesticides exposure is needed. Pre-exposure value and/or reference value of relevant indicators are necessary for assessing the degree of exposure and absorption.

Cross-resistance of dicofol-resistant Tetranychus urticae Koch to 21 pesticides was evaluated. Initial investigations used field-collected dicofol-resistant and susceptible colonies. Near-isogenic lines, constructed by a series of backcrosses, were used to confirm or reject determinations of cross-resistance derived from evaluations of field-collected colonies. Dicofol-resistant T. urticae showed strong positive cross-resistance to amitraz, bromopropylate, and chlorobenzilate. Moderate negative cross-resistance to ward chlorpyrifos was observed. These results suggest that amitraz, bromopropylate, and chlorobenzilate should not be used in alternation with dicofol in a resistance management program designed to exploit the instability of dicofol resistance. The uptake and distribution of (14C)-dicofol was investigated in near-isogenic lines of susceptible and resistant mites. No difference in the uptake of radiolabel was observed between strains, suggesting that decreased penetration is not a major mechanism of dicofol resistance. In vivo metabolism studies revealed greater production of water soluble metabolites and lower levels of internal dicofol in the resistant strain compared with the susceptible. Therefore, the major mechanism of resistance to dicofol appears to be increased metabolic detoxification.

Twenty-four-hour urine samples were examined for 4,4′-dichlorobenzilic acid (DBA) pre-, during and post-exposure of dicofol applicators and mixer-loaders. Pre-exposure DBA excretion rates were not zero, since chlorobenzilate, a compound also yielding DBA as a urinary metabolite, had been used previously by the workers. Among workers, mean daily DBA excretion rates during the exposure period ranged from 19 to 42 μ g/day. Ninety-eight percent of this variation was explained by differences in estimated dicofol deposits onto their skin. Only (0.25 ± 0.02)% of the estimated dermal deposit appeared as urinary DBA. Post-exposure urinary DBA declined with a half-life of 7 ± 4 days.

Field experiments were conducted between 1981 and 1988 to evaluate the potential of zineb (zinc ethylene bisdithiocarbamate), mancozeb (a coordination product of zinc ion and manganese ethylene bisdithiocarbamate) and carbamate (ferric dimethyldithiocarbamate) in combination with one or more of the following acaricides: ethion, chlorpyrifos, dicofol, chlorobenzilate, propargite or formetanate for the control of the citrus rust mite, Phyllocoptruta oleivora (Ashmead) (Acari:Eriophyidae). Treatments were applied to replicated single tree plots using a handgun from a truck-mounted sprayer or to replicated nine tree plots using an airblast sprayer during the postbloom, summer or supplemental fall spray periods. Mancozeb alone was slightly better than zineb alone in the suppression of P. oleivora. However, neither compound demonstrated sufficient activity to justify its use alone as an acaricide on citrus. The combinations of ethion, chlorpyrifos, dicofol or propargite with either mancozeb or zineb sh...

In the modern era of industrialization, due to increase in the developmental activities, water is being polluted. It is essential to monitor and prevent the pollution load in drinking water as it has a direct link to human health. The objective of this study was to determine physico-chemical characteristics, bacterial contamination and pesticides in tap water samples collected from various selected sites of Noida City. Tap water samples were assessed for physico-chemical parameters like; pH, Dissolved Oxygen (DO), Total Dissolved Solids (TDS), Total Hardness, Alkalinity, Fluoride (F), Nitrate (NO3–3) and Sulfate (SO4–2). The water samples were also analyzed for the presence of fecal bacteria namely: Escherichia coli (E.coli), Salmonella, Pseudomonas aeruginosa, Staphylococcus aureus and total coliform bacteria present in tap water. Pesticides namely: Chlorobenzilate, Hexachlorobenzene, Benzenether, pp-DDT, op-DDT, pp-DDE, pp-DDD, alpha-HCH, Beta-HCH, Lindane, Vinclozolin, Conumaphos, Malathion, Phosalone, Cyfluthrin, Cypermethrin, Deltamethrin, Permethrin, Fenvalerate, Fluvalinate, Cyhalothrin, Carbofurn, Propoxeur, Carbaryl, Cymiazol, Amitraz, Bromprophylate, Chinomethionate were also detected.

Publisher Summary The use of pesticides has resulted in selection for physiological resistance in a number of populations of eriophyoid mites of several species. This chapter distinguishes between “resistance,” in which a population initially susceptible to a compound responds to selection pressure by an increase in the frequency of nonsusceptible genotypes, and “tolerance,” in which the physiological mode of action of a chemical is initially not toxic to most of the population. Eriophyoids are known to be innately tolerant to some compounds, which otherwise show broad acaricidal properties towards tetranychids and other mites. Some species may be tolerant to acaricides, which are effective against other eriophyoids; the blueberry rust mite, Acalitus vaccinii , is reported to be tolerant to tetradifon, dicofol, propargite, and chlorobenzilate. Pesticide resistance problems in eriophyoids have not been as severe as in tetranychid mites and other insect pests. However, several factors, including the use of more selective pesticides for spider mite control and the change from acaricidal to non-acaricidal fungicides, may lead to increased problems with eriophyoids in the future.

Ten chlorinated hydrocarbons (tetradifon, Chlorobenzilate, Kepone, lindane, Kelthane, toxaphene, dieldrin, hexachlorobenzene, dienochlor, and Aroclor 1254; see below) were evaluated in rats to assess agents which might selectively elevate high-density lipoprotein cholesterol (C-HDL). Single, nontoxic doses of Aroclor, dieldrin, and Kepone elevated C-HDL at day 7 (31%, 26%, and 24%, respectively, p less than 0.05). The C-HDL elevations were maintained at days 21 and 60 (28% and 31%, p less than 0.01) in the Aroclor group, while C-HDL returned to baseline in the dieldrin and Kepone groups. Liver function tests were unchanged from control, suggesting that the changes in C-HDL were not the consequence of hepatotoxicity. The hepatic microsomal cytochrome P-450 content of animals receiving Aroclor, dieldrin, and Kepone was 67%, 56%, and 44% higher than control values (p less than 0.02), indicating probable hepatic enzyme induction. If HDL (an antiatherogenic lipoprotein) is also selectively elevated by chlorinated hydrocarbons in man, then analogues might potentially be developed as antiatherogenic pharmacologic agents. Alternatively, the implications of man's exposure to halogenated hydrocarbons may be better understood.

Chlorobenzilate residues were determined on citrus foliage, fruit, and soil surfaces. Residue half-lives varied from 4 to 21 days depending on extraction method and time of the year. Increasing the application rate resulted in a proportional increase in residues. The standard “dislodgeable” method recovered less surface residues than did a methanol recovery. These data are discussed in relation to protecting harvesters from pesticides.

The toxicity of 15 citricultural pesticides to a San Joaquin Valley, California strain of Euseius hibisci (Chant) were evaluated in laboratory bioassays by use of the leaf disc-dip technique. Compounds of low toxicity were parathion, carbaryl, sabadilla, and fenbutatin-oxide. Malathion, methidathion, and propargite were moderately toxic to E. hibisci. Compounds highly toxic to this predatory phytoseiid were methomyl, acephate, cyhexatin, dimethoate, dicofol, chlorpyrifos, oxythioquinox, and chlorobenzilate. Adult females were highly sensitive to methomylleaf residues. A majority of females moved off into the water barrier soon after their placement on the treated surface at levels as low as 0.94 g (AI)/100 liters. The potential for augmentation and conservation of the strain for the biological control of spider mites and citrus thrips in San Joaquin Valley citrus integrated pest management programs are suggested.

Laboratory bioassays were conducted on leaf discs to determine the impact of 20 pesticides on two strains of Euseius hibisci (Chant) colonized from citrus. The herbicides and fungicides tested were modestly lethal to both E. hibisci strains. However, paraquat, glyphosate, and dikar expressed toxicity to E. hibisci . Laboratory bioassays showed that E. hibisci ’s tolerance to chlorobenzilate was moderate for both strains as compared with dicofol. Azinphosmethyl, methidathion, and sulfur exhibited moderate acaricidal activity to the RH strain as compared with our standard LAB strain. E. hibisci was very susceptible to methomyl. Dimethoate was the only OP which caused high mortality in both strains. Although the resistance level of the RH strain to dimethoate was considerably lower than the recommended field dosage, it was 22-fold that of the LAB strain.

Impacts of field-weathered residues of nine acaricides (amitraz, avermectin + oil, chlorobenzilate + oil, cyhexatin, dicofol, fenbutatin-oxide, oil, oxythioquinox, and propargite) on survival of selected beneficial arthropods of citrus ( Aphytis melinus DeBach, Cryptolaemus montrouzieri Mulsant, and Euseius stipulatus Athias-Henriot) were evaluated in two field trials. Concurrent with bioassays, foliar residue analyses were performed and were correlated with mortality. With the exception of moderate (causing amitraz > oxythioquinox > cyhexatin > chlorobenzilate + oil > propargite (least persistently toxic).

A total of 228 pesticides (88 insecticides, 60 fungicides, 62 herbicides, 12 plant-growth regulators, 3 metabolites and 3 other compounds) was tested for mutagenicity in bacterial reversion-assay systems with 5 strains (TA100, TA98, TA1535, TA1537 and TA1538) of Salmonella typhimurium and a strain (WP2 hcr) of Escherichia coli. 50 pesticides (25 insecticides, 20 fungicides, 3 herbicides, 1 plant-growth regulator and 1 other compound) were found to be mutagenic. 5 of them required metabolic activation (S9 mix) for their activities. Among various chemical groups, organic phosphates, halogenated alkanes and dithiocarbamates showed higher ratios of mutagens. Although 22 of the pesticides tested have been reported to be carcinogenic, 7 of them, i.e., captain, DBCP, EDB, EDC, ETU, HEH and nitrofen, were detected as mutagens in the present assay. Most of the other 15 non-mutagenic carcinogens were organochlorine pesticides such as alpha-BHC, chlorobenzilate, p,p'-DDT, dieldrin and quintozene.

Field experiments in an apple orchard and in a citrus grove were carried out to evaluate the effect of four commercial pesticides in common use in Israel against apple and citrus pests, on the spider populations inhabiting the trees. The spider populations on apple were markedly suppressed by the pesticides, the order of toxicity being Talstar (biphenate) >Mavrik (fluvalinate) > Smash (fenpropathrin) > Dursban (chlorpyrifos). When grapefruit trees were treated with carbaryl + formothion, 232 spiders were sampled in the unsprayed plot, 55 days after treatment, as compared with only 11 spiders in the treated plot. Two and 7 days after treatment with chlorobenzilate, the sample from the treated plot numbered 68 and 55 spiders, respectively, as compared with 50 spiders collected 24 h before treatment. In addition, laboratory tests were carried out to determine the susceptibility of the spiderChiracanthium mildei L. Koch to 17 pesticides. When the spiders were exposed to grapefruit leaves which had been dipped 1 h previously for 5 sec in the aqueous emulsions of the pesticides, chlorpyrifos, fenpropathrin, fenvalerate, phosphamidon and biphenate caused 100%, and cypermethrin and fluvalinate 60% mortality, whereas all the other pesticides tested - acaricides, fungicides and herbicides - caused about 10-40% mortality.

Population dynamics and biological control of the citrus thrips, Scirtothrips citri (Moulton), was studied over a 3-year peiod on ‘Washington’ navel orange, ‘Lisbon’ lemon, and ‘Marsh’ grapefruit near Corona (Riverside County), Calif. The native phytoseiid predator, Euseius hibisci (Chant), was excluded from experimental plots in citrus groves by spraying a residue of malathion on plot trees and those surrounding the plots. Subsequent mass release of this predator into these plots suppressed the citrus thrips below economic levels. In plots that had been sprayed with malathion, the disappearance of the insecticide from the leaves was monitored. The leaf residues did not stimulate fecundity of the citrus thrips by early summer. Early spring populations of >0.50 E. hibisci per leaf on inland valley citrus groves of southern California responded numerically and functionally to second- and third-generation increases of S. citri . These responses by E. hibisci occurred before citrus thrips could irreparably damage the rind of fruit of ≤4 cm diameter. Field trials on lemon were designed to assess the effect of five citrus pesticides on the Corona Foothill strain of E. hibisci . Dimethoate, methomyl, and parathion were extremely toxic to E. hibisci ; residual toxicity of chlorobenzilate and carbaryl to the predator 26 days posttreatment was comparable to the water control.

A Rebuttable Presumption Against Registration (RPAR) was issued for chlorobenzilate (CB) in May, 1976 (BOYD 1978). In June, 1978 a Notice of Determination was published by the U.S. Environmental Protection Agency because the presumptive cancer r isk associated with exposure to the acaricide had not been adequately negated by assessment and research. By February, 1979 a Notice of Intent to cancel a l l non-citrus uses of CB was issued. Use of chlorobenzilate was thereby l imited to c i t rus crops grown in Texas, Cal i fornia and Florida. The conditions for reg is t ra t ion of CB were also made more str ingent : ( I ) i t was rec lass i f ied as a rest r ic ted use pest icide, (2) a new label indicat ing s t r i c t e r use conditions was required and (3) u t i l i za t i on of more effect ive protective clothing and equipment were recommended.

A gas-liquid chromatographic method for the determination of chlorobenzilate and chloropropylate in liquid formulations containing about 46 and 26% active ingredient, respectively, was collaboratively studied, using a matched pair scheme. The samples were dissolved in acetone containing dibenzyl succinate as an internal standard and chromatographed on Carbowax 20M, using a flame ionization detector. Analyses of 4 samples by 13 collaborators using peak height measurements showed the following results: chlorobenzilate—2.5% overall coefficient of variation, 1.0% coefficient of variation for the random error; and 0.7% systematic error; chloropropylate—2.0, 1.4, and 0.4%, respectively. The method has been adopted as official first action.

An evaluation of 17 chemicals was conducted in the field at Mwea-Tebere Agricultural Research Station to ascertain their efficacy against the red spider mites Tetranychus sp. attacking cotton in Eastern Kenya. The study became necessary owing to the inadequate control of red spider mites by the recommended acaricide, Dimethoate. Of the chemicals that performed well against the red spider mites, Kelthane, Akar, Morestan and Neoron were considered to be the most suitable replacements for Dimethoate because of their low levels of mammalian oral toxicity. Judged from the overall performance against the red spider mites, these acaricides were also about twice as effective as Dimethoate.

The relationship between posttreatment temperatures of 15°, 20°, 25°, and 30°C and toxicity of six pesticides to adult female Phytoseiulus persimilis Athias-Henriot and Tetranychus urticae Koch were studied in the laboratory.The toxicities of cyhexatin, dicofol, propargite, citrazon, chlorobenzilate, and per-methrin were positively correlated with temperature. Except for propargite and permefhrin, P. persimilis was less susceptible than T. urticae at 15° and 20°C, but equal in susceptibility at 25° and 30°C.The results obtained may indicate a potential value of posttreatment temperature manipulation as a useful adjunct to integrated pest control programs in glasshouses.

The maximal tolerated dose of chlorobenzilate was given by continuous oral administration, starting at the age of 7 days, to both sexes of two hybrid strains of mice-(C57BL/6 X C3HAnf)F1 and (C57BL/6 X AKR)F1. There was an increased incidence of tumors in one or more organs in male mice of both strains and female mice of the (C57BL/6 X C3HAnf)F1 strain. Male mice of both strains developed significantly elevated incidences of carcinomas of the liver. Female (C57BL/6 X C3HAnf)F1 strain mice had a significantly increased incidence of hyperplasia and carcinomas of the forestomach.

The direct toxicity of 5 common acaricides toAmblyseius brazilli El-Banhawy was tested. Omethoate proved to be the most toxic and Chlorobenzilate the least toxic. LC50 were 1.2ppm, 220ppm, 720ppm and 1250ppm for Omethoate, Mexacarbate, Dicofol, Mitran and Chlorobenzilate respectively. The indirect toxicity was also studied by providing the female predators with the phytophagous miteAponicus spinosus (Banks) previously treated by Chlorobenzilate and Mexacarbate. The females were fed on the treated as well as the untreated prey. The eg laying was interrupted and almost stopped in the case of Mexacarbate.

Simultaneous determination method of 8 kinds of acaricides (amitraz, benzomate, dicofol (kelthane), chlorfenson (CPCBS), chlorobenzilate, chloropropylate, phenisobromolate and tetradifon) was investigated. Twenty g of minced fruits or vegetables were homogenized with acetone or acetone containing 30% of water. Fifteen g of NaCl was added to each sample, and acaricides were extracted with n-hexane containing 20% ethyl acetate. Three ml of xylene was added to the extract, removed n-hexane-acetone mixture, and this xylene-substituted extract was applied on a florisil column. The column was washed with 50 ml of n-hexane and eluted with 100 ml of n-hexane containing 30% ethyl acetate. Eluate was concentrated to 3.0 ml. Benzomate, kelthane, chlorfenson, chlorobenzilate chloropropylate, phenisobromolate and tetradifon were determined by ECD-GC using capillary column of CBP-1. Amitraz was determined by FTD-GC using OV-17 column. Contents of 8 acaricides in samples including fruits, vegetables, green tea and brown rice were below 0.01 ppm. Recoveries of 8 acaricides added at the concentrations of 0.25-5 ppm in these samples were 60.0-99.9%. Therefore, this method was applicable to the determination of acaricides in agricultural products.

Laboratory cultures of the granary weevil, Sitophilus granarius (L.), and the rice weevil, Sitophilus oryza (L.), were invaded by mites of two genera, Typhlodromus and Acaropsis. Several acaricides were tested for the purpose of eliminating mites from rearing and testing areas of the laboratory without causing undue harm to insects in cultures. Methods are described for the use of Kelthane and Chlorobenzilate to eradicate mites in rearing and testing areas of a stored-product insects laboratory, the use of Kelthane for the control of mites in weevil cultures, and for the prevention of new infestations.

High-gallonage sprays were applied to greenhouse roses heavily infested with two-spotted spider mites ( Tetranychlls telarius (L.)) to determine the extent of resistance and what groups of compounds might afford practical control. The results indicate that resistance has developed to most of the materials previously used for mite control; these include Aramite® (2-( p-tert -butylphenoxy) isopropy! 2-chloroethyl-sulphite), chlorobenzilate, tetradifon, tepp, malathion, and schradan. There is also evidence that cross resistance has developed to numerous pesticides, for many that have not previously been used were nevertheless ineffective. It is apparent from this study that compounds unrelated to previously used acaricides are effective against these resistant mites. Binapacryl, Eradex® (2,3-quinoxalinedithiol cyclic trithiocarbonate), and Bayer 36205 (6-methyl-2,3-quinoxalinedithiol cyclic carbonate) can be placed in this category but cannot be used at effective dosages because of phytotoxicity on roses. Pentac (bis(pentachloro-2,4-cyclopentadien-5-yl), and Bidrin® (3-hydroxy- -N,N -dimethyl- cis -croton-amide dimethyl phosphate) represent two dissimilar materials that show promise for control of resistant mites on roses. Pentac, with its low mammalian toxicity and lack of phytotoxicity, has already proven to be a highly practical and effective control.

Two days after moulting to the 3rd instar, larvae of Chrysopa rufilabris Burmeister were exposed to technical and commercial formulations of 5 pesticides. Technical pesticides in decreasing order of toxicity to C. rufilabris larvae were: azinphosmethyl, carbaryl, ethion, carbophenothion, and chlorobenzilate. Residues of commercial azinphosmethyl 2 EC and carbaryl 50% WP had high and medium toxicity, respectively. Ethion + oil, carbophenothion 2 EC, and ethion 4 EC had low toxicity, while chlorobenzilate 25% EC had 0 toxicity. Azinphosmethyl and carbaryl residues were toxic up to 22 days postapplication. Ethion + oil, carbophenothion, and ethion showed 0 toxicity after 6 days.

A strain of the Pacific spider mite, Tetranychus pacificus McGregor, which had developed resistance in the field to demeton treatments was subjected in the laboratory to parathion selection pressure at the 70% mortality level through 10 selections without further change in the degree of cross resistance to parathion. Starting with a susceptible strain, six to nine such selections with parathion and ethion resulted in high degrees of resistance to both accuracies. Similar selection procedures using Aramite® (2-( p-tert -butylphenoxy) isopropyl 2-chloroethyl sulfite) resulted in a 10-fold increase in resistance after 15 selections; but using Chlorobenzilate® (ethyl 4,4′-dichlorobenzilate or Kelthane® (1, 1-bis( p -chlorophenyl)-2,2,2-trichloroethanol) resulted in no change in susceptibility after 23 or 22 selections, respectively. In cross resistance evaluations parathion- and ethion-resistant strains were cross resistant to the other organ phosphorus accuracies evaluated but not to the specific acaricides. Aramite-, Chlorobenzilate-, and Kelthane-selected strains were cross resistant to some organophosphorus compounds but not to other specific acaricides. This response is contrasted with the response of house flies ( Musca domestica L.) to selection pressure with insecticides.

Two species of predaceous typhlodromid mites Typhlodromus fallacie (Garman) and Phytoseiulus persimilis A.-H. are important natural biological agents in the suppression of spider mite populations. A study was made to determine the possibility of developing an integrated biological-chemical control program by selecting pesticides least toxic to the typhlodromids and yet effective as control for diseases and insects on the host crops. Of 31 pesticides tested, the predaceous mites tolerated residues of 12 chemicals that included the insecticides aldrin, dieldrin and endrin; the acaricides Aramitc® (2-( p-tert -butylphenoxy) isopropyl 2-chloroethyl sulfite), chlorobenzilate, Kelthane® (1,1-bis( p -chlorophenyl)-2,2,2-trichloroethanol), tetradifon, and ovex; and the fungicides captan, maneb, Folpet® ( N -(trichloromethylthio) phthalimide), and zineb. The results of present studies encourage further investigations to evaluate the control of spider mite populations using predator mite releases alone or in combination with a selective spray program.

Chlorobenzilate (ethyl 4,4′-dichlorobenzilate), chloropropylate (isopropyl 4,4′-dichlorobenzilate), and bromopropylate (isopropyl 4,4′-dibromobenzilate) were metabolized by rat liver preparations, with the microsomal and the nuclear supernatant fractions being most active. The limiting reaction was cleavage of the ester linkage by carboxylesterases, which showed greater activity for the ethyl ester (chlorobenzilate) than for the isopropyl ester (chloropropylate and bromopropylate). This initial reaction was blocked by the organophosphate DFP (diisopropyl phosphorofluoridate). SKF-525A enhanced to some extent the degradation of chlorobenzilate by the mitochondrial and possibly the microsomal fractions. p-Chlorobenzoic acid from chlorobenzilate and chloropropylate and p-bromobenzoic acid from bromopropylate were the identified end products of acaricide metabolism by the hepatic enzymes.

Grove and laboratory studies showed that Aleurodothrips fasciapennis (Franklin) is more numerous in the spring and early summer, completes a life cycle in about 4 weeks, will feed and develop on the purple scale ( Lepidosaphes beckii (Newman)), Florida red scale ( Chrysoinphalus aonidum (L.)), chaff scale ( Parlatoria pergandii Comstock), cloudy-winged whitefly ( Dialeurodes citrifolii (Morgan)), and six-spotted mite ( Eotetranychus sexmaculatus (Riley)), but is more vigorous on the armored scales (Diaspididae). This predatory thrips was found to fluctuate numerically with the populations of purple scales and to be severely affected by parathion, moderately by chlorobenzilate (ethyl 4,4´-dichlorobenzilate), and acid lead arsenate and slightly or not at all by zineb, sulfur, and copper.

Little work has been reported on the control of eriophyid mites with synthetic organic acaricides, and virtually none on the wheat curl mite, Aceria tulipae (Keif.). Rolling of the leaves caused by this species and the tendency for some mites to occur deep in the leaf sheaths between two surfaces protects them from sprays and suggested the translocation of systemic insecticides as the most promising means of control. Spraying with 30 different insecticides in greenhouse and field in the spring resulted in none that gave both high initial and long residual control. Eighty to 90% control was obtained at 2 to 3 days in the field with several insecticides but none exceeded 90% control. Best control at 5 weeks following spraying of young wheat in the fall was obtained with endrin in light mineral seal oil. After determining the maximum concentration of each systemic toxicant that was not highly detrimental to germination, three concentrations of each toxicant were tested. Retardation and/or reduction in germination resulted from the use of all seed treatments, although not above the 5% confidence limit in most cases when the toxicant did not exceed 0.125 pound per bushel. Impregnation of the toxicant in 4 pounds of Carhowax-6000 per bushel of seed, gave better control than soil drenches. Am. Cyanamid 12009 (95% control) and 12008 (85% control) at an average from 0.125 to 0.5 pound of toxicant in 4 pounds of Carbowax per bushel of seed, gave the best overall results at the end of 1 week. When these toxicants were impregnated in attac1ay at 1.0 pound toxicant per bushel, 89 and 74% control, respectively, was obtained at 1 week and 98 and 97%, respectively, at the end of 5 weeks. In field studies on plantings of fall-treated seed, best results, using Am. Cyanamid 12008 (89% control) and 12009 (72% control), were recorded at 5 weeks when the toxicant was used without being impregnated in granules. Mites were present in all cases when counts were made 10 weeks following planting as well as during the following spring. In no instance was control of wheat-streak mosaic obtained from seed treatments in 1954 when viruliferous mites were constantly introduced in large numbers onto the young wheat plants.

Studies of populations of the citrus bud mite, Aceria sheldoni (Ewing). over a period of 2 to 5 years in treated and untreated plots in four southern California lemon orchards are reported. In untreated plots a rapid increase in infestations in lemon buds started in Mayor June and peaked in August or September. In some years high populations were maintained throughout the fall and winter; in other years populations gradually decreased during the winter. In either case, populations fell to an annual low during April and May. These general population trends were correlated with seasonal climatic changes and plant growth cycles. Warm summer weather favorable for plant growth and also for mite dispersal resulted in rapid increase in infestation, whereas winter conditions appeared to reduce movement from one bud to another. Periods of low humidity during the winter or spring appeared to be major factors in the decline of infestation within the buds during this period. An unusually hot period in September 1955 resulted in a sharp decrease of infestation, especially in the orchard farthest from the coast. The summer population increase was about 1 month later under fruit buttons than in the buds. Populations under fruit buttons were higher than bud populations during most of the year. Applications of petroleum oil and of Aramite in both fall and spring were necessary for adequate control. Chlorobenzilate was most effective when applied between the first of June and the last of September, and a single application during this period kept mite populations low for a year.