Sprays Of Malathion Research Articles

Effect of spraying selected pesticides on the contents of specified minerals in cabbage.

The present study was conducted to assess the effect of spraying of pesticides on the content of minerals in cabbage harvested at varying waiting periods (0, 7, 14 and 21 days) after spraying. The amounts of phosphorus and zinc in cabbage were significantly (p < 0.05) decreased while those of iron, calcium and potassium were significantly (p < 0.05) increased by the sprayings of pesticides. At varying waiting periods after the spraying of pesticides calcium, phosphorus, zinc and potassium contents of cabbage were found to be decreased remarkably (p < 0.05) while the content of iron was increased significantly (p < 0.05). Between the two pesticides, the spraying of endosulfan exerted a more pronounced effect in altering the contents of minerals than the spraying of malathion.

Yellowfever mosquito (Diptera:Culicidae) introduced into Landi Kotal, Pakistan, by tire importation.

Although the recent distribution of yellowfever mosquito, Aedes aegypti (L.), in Pakistan has been restricted to the port city of Karachi, adult and immature mosquitoes breeding in imported tires in warehouses at Landi Kotal (North-West Frontier Province) were identified as Ae. aegypti. The patterns of tire trade and the current disjunct distribution of Ae. aegypti indicated that the introduction into Landi Kotal may have been either from Karachi or India. Thermal fog application of pirimiphos-methyl and residual spray of malathion during 1993 reduced abundance in October-November. Living larvae or adults were not found during January 1994, apparently because of cold weather. However, Ae. aegypti reappeared during May-June 1994, most probably from eggs that overwintered. Population increased during late August when another round of spray using the same insecticides and fenthion as an additional larvicide again reduced abundance. Although this mosquito apparently has not spread into neighboring areas, its survival at Landi Kotal through all seasons despite control measures indicates its potential of becoming established in other areas of Pakistan.

EVALUATION OF INSECTICIDES FOR CONTROL OF PAINTEDBUG ON TARAMIRA

A field experiment was conducted during rabi 1986-87 with RTM-2 variety of rocket (Eruca sativa Miller) to evaluate the efficacy of seven insecticides against painted bug. Bagradu hilaris Burm. The sprays of malathion; 0.05 per cent, dimethoate 0.03 per cent and monocrotophos 0.036 per cent were found effective for control of this pest.

Efficacy of Vacuum Machines for Lygus hesperus (Hemiptera: Miridae) Control in Coastal California Strawberries

Three representative suction machines were evaluated for control of Lygus hesperus (Knight) on strawberries for two growing seasons in production fields. Weekly and twice-weekly vacuum passes through a field were compared with bifenthrin applications in 1989. Weekly and twice-weekly vacuum passes were compared with bifenthrin (0.11 kg [AI]/ha) and malathion (1.26 kg [AI]/ha) sprays applied using a degree-day phenology model and with a combination of malathion and weekly vacuuming in 1990. All three machines reduced damage caused by L. hesperus when compared with the untreated control. The three-bed vacuum is the largest machine, with the highest air flow, tested, resulting in a significant reduction in damage compared with the untreated. The smaller one-bed and two-bed machines did not decrease the numbers of nymphs or damage. However, the treatments in which vacuum machines were used exclusively had damage that was not economically acceptable. Twice-weekly vacuum passes did not improve L. hesperus control compared with weekly vacuum passes. Weekly vacuum passes combined with malathion sprays were no better than either treatment alone. Bifenthrin provided effective control but resulted in spider mite (244.6 mites per leaflet) population increases after 3-4 wk. Weekly vacuum treatments provided control of L. hesperus equal to that of one or two applications of malathion.

Droplet size characterization of three aerial malathion spray programs

The Mediterranean fruit fly, Ceratitis capitata, and the Mexican fruit fly, Awls.:. trnpha lu<lens are major agricultural pests, capable of destroying a wide variety of fruit. It is the policy of the California Department of Food and Agricult ure (CDFA) to pursue eradication of fruit fly populations to prevent establishment in California. A component of the eradication efforts in the past has been the aerial application of a malathion UL V/Nu-Lure® bait mixture. Three aerial spra y pro­ grams have been monitored by the Environmental Hazards Assessment Program of CDP A. Specifically, these were the eradication of the Mediterranean fruit fly (Medfly), in the Santa Clara Valley in 1981 (Oshima et. al. , 1982) and the Los An­ geles area in 1990 (Segawa et. al., 1991) and the Mexican fruit fly (Mexfly) in the El Cajon (San Diego ) area in 1990 (T urner et. al., 1991). Extensive monito ring of the 1981 application and resulting public and environmental exposure have been presente d (Discher, 1982; Finlayson et. al., 1982; Grether et. al., 1987; Oshima et. al., 1982). The two 1990 eradication programs were less extensivly monitored. One of the components of the monitoring program s for these sprays was the col­ lection of droplet size data. Because of the possibility of additional aerial applica­ tions of malathion/bait in future eradication projects, additional analysis of the droplet size data from the three previous studies was undertaken. Continuing pub­ lic concern over the aerial application of malathion/bait warranted additional anal­ ysis of droplet size because of possible effects of droplet size on drift and vol­ atilization of malat hion. Therefore, the primary focus of the analysis was on droplet size differences between spray programs and on droplet size as it affects human and environmental exposure. The differences in aerial applicat ions be­ tween 1981and1990 add some confounding effects to the analysis. However, given the large amounts of time and effort which have gone into the collection of the monitoring data in the past and the expense that would be required to conduct a controlled aeri al exposure for experimental monitoring purposes, this analysis is the only realistic option available at the present time.

Controle biológico do ácaro rajado com ácaros predadores fitoseídeos (Acari: Tetranychidae, Phytoseiidae) em culturas de pepino e morango

O ácaro rajado, Tetranychus urticae Koch, é considerado uma das principais pragas de hortaliças e várias outras culturas no Brasil, em áreas onde um considerável volume de acaricidas é anualmente empregado no seu controle. O objetivo deste trabalho foi testar a viabilidade técnica do emprego dos fitoseídeos Amblyseius idaeus (Denmark &amp; Muma) e Phytoseudus macropilis (Banks), comum ente encontrados no Brasil, no controle de T. urticae em pepino e morangueiro em Jaguaríúna,SP. Utilizou-se o delineamento experimental em blocos casualizados, com 4 repetições e 4 tratamentos (T1-T4) para o pepino e 5 tratamentos para o morangueiro (T1-T5): T1, testemunha; T2, pulverizações semanais de Malation para a exclusão de predadores nativos; T3, liberações periódicas de A.idaeus; T4, liberações periódicas de P.macropilis; T5, pulverizações semanais de avermectina para a exclusão de ácaros fitófagos e predadores nativos. Apenas A.idaeus se estabeleceu na cultura de pepino, reduzindo significativamente a população de T. urticae. Ambas espécies de predadores se estabeleceram na cultura do morango e reduziram significativamente a população de T.urticae.

Monitoring of malathion and its impurities and environmental transformation products on surfaces and in air following an aerial application

Concentrations in air and on surfaces of malathion and impurities [malaoxon, isomalathion, O,O,S-trimethyl phosphorodithioate, O,O,O-trimethyl phosphorothioate, O,O,S-trimethyl phosphorothioate, and diethyl fumarate (DEF)] were determined at three sites during and for 9 days after a 1990 aerial spraying in California. Malathion spray was transformed via oxidation to malaoxon, hydrolysis to DEF, and selective volatilization. Malathion half-lives were 1.6 to >9 days, and depositions at three sites ranged from 1100 to 2413 μg/ft 2 , while malaoxon ranged from 2.9 to 6.0 μg/ft 2 .

Studies of the impact ofEuseius species (Acari: Phytoseiidae) on citrus mites using predator exclusion and predator release experiments

To create plots with differential levels ofEuseius, malathion sprays, highly toxic to phytoseiids but of low toxicity to citrus red mite,Panonychus citri (CRM), and citrus thrips,Scirtothrips citri, were applied to blocks of “Valencia” oranges for three seasons (1984, 1985 and 1986) and “Eureka” lemons for one season (1985). Releases ofEuseius spp. were made in plots within the treated blocks. In 1984, CRM populations were highest in the treated/no release plot, lowest in the untreated and intermediate in the treated/Euseius stipulatus-release plot. In 1985, CRM populations were high in all plots in the oranges (including theE. tularensis release) except theE. stipulatus-release plot, and in all plots in the lemons except the untreated.Euseius releases in the lemons had no effect, apparently because they were followed by very hot weather. In 1986, CRM was very low in all plots.Euseius stipulatus became the dominant phytoseiid species even in theE. tularensis-release plots after a few weeks, indicating that this species colonized more readily and spread to other trees more rapidly than didE. tularensis. The results support the hypothesis thatE. stipulatus is an important mortality factor contributing to CRM control at low levels.Euseius stipulatus also may have a negative impact on the citrus rust mite,Phyllocoptruta oleivora. Citrus thrips populations were low during the entire study period and did not differ significantly between plots.

Differential Selection of Malathion Resistance in Anopheles culicifacies A and B (Diptera: Culicidae) in Haryana State, India

In November 1989, for the first time after the introduction of malathion spray in 1982, increased densities of Anopheles culicifacies Giles s.l. were observed in Chhatera and Barota, two villages in Halalpur block in Sonepat District, Haryana State, India. In bioassay tests against the diagnostic dose of malathion (5% for 1 h), 41-47% of mosquitoes survived. An culicifacies populations in this area comprise two sibling species, A and B. Differential malathion resistance was observed; in species A it was 2-9% and in species B 62-66%. Likewise, species A was found to be more susceptible to DDT than was species B. The possible use of DDT spray to delay the onset of malathion resistance is discussed.

Effect of Habitat and Perturbation on Populations and Community Structure of Darkling Beetles (Coleoptera: Tenebrionidne) on Mixed-grass Rangeland

A study was conducted in 1986 and 1987 to determine the effects of perturbation and habitat characteristics on the population dynamics and community structure of darkling beetles on mixed-grass rangeland. Two 1,400-ha blocks of rangeland in western South Dakota were treated aerially with malathion liquid spray or carbaryl-bran bait in early July 1986 to determine the immediate and second-year effect of treatments on darkling beetles, as well as grasshoppers and other nontarget arthropods. Populations of the dominant species (83% of total), Eleodes opacus (Say), were reduced significantly by 59.2 and 87.9% in the carbaryl-bran bait and malathion spray treatment plots, respectively, within 1 wk of treatment and remained at low levels throughout the rest of the summer. Populations did not change significantly in the control plots. Populations of the next three most abundant species (15.7% of total), E. tricostatus (Say), E. obsoleta (Say), and E. suturalis (Say), were negatively affected by one or both treatments. Populations increased to or above pretreatment levels in 1987 in treated and control plots. Analysis of covariance of the abundance of darkling beetles during July 1987, with pretreatment abundance as a covariable, indicated that treatment (treatment and block effects combined) had no significant effect on second-year populations of E. opacus, E. obsoleta , or E. suturalis , but did explain a significant amount of variation of second-year populations of E. tricostatus . However, the covariable, pretreatment abundance, was significantly correlated with July 1987 population levels of E. opacus, E. tricostatus , and E. obsoleta . The multivariate technique, detrended correspondence analysis (DCA), was used to ordinate undisturbed communities along ecological gradients, and correlation analysis of DCA axes values with habitat variables was used to define specific gradients underlying the community structure of darkling beetles. Analysis of abundance and incidence data indicated that darkling beetle communities were ordinated along ecological gradients of percentage of grass coverage, particularly Buchloe dactyloides (Nutt.) Engelm. and Bromus spp., coverage of several forb species, and percentage of sand and clay in the soil. Numbers of total darkling beetles, E. opacus , and E. obsoleta , and species richness increased along a gradient defined by coverage of grass and percentage of sand. E. suturalis decreased along the same gradient.

BIOLOGY AND CONTROL OF THE REDNECKED CANE BORER, AGRILUS RUFICOLLIS (F.) (COLEOPTERA: BUPRESTIDAE), ON BLACKBERRIES IN ARKANSAS1

Studies of methods for adult detection, development and control of the rednecked cane borer (RNCB), Agrilus ruficollis (F.), in blackberries were conducted in Goshen and Fayetteville, Arkansas from 1984 through 1987. Colored sticky traps were shown to be ineffective since they captured a total of only 13 RNCB adults over a two-year period. Pupae began to transform to inactive adults by 2 May 1985, 29 April 1986 and 4 May 1987. The earliest reported emergence of RNCB adults was between 22 and 29 April 1986. The latest completion of adult emergence was 8 June 1987. Adults in the field emerged from blackberry canes over a two to four week period. Adults that emerged in the insectary in 1984 lived for 13.4 days ± 1.7 SEM. Insecticide evaluations demonstrated that sprays of malathion, chlorpyrifos and methoxychlor resulted in adequate control of RNCB. Carbaryl did kill RNCB adults quickly as noted by 75 percent mortality inside exit holes, but a more frequent spray schedule would be required to give adequate control.

Effect of malathion-bait mixture on two parasitoids of the Florida red scale, Chrysomphalus aonidum (L.)

Experiments with laboratory populations have shown that immature stages of the hymenopterous parasitoids, Aphytis holoxanthus DeBach and Pteroptrix smithi (Compere) were unaffected by a malathion-bait mixture (0 · 13% malathion) applied to their host, Chrysomphalus aonidum (L.). However, the emerging adults of A. holoxanthus were highly susceptible and it was clearly shown that malathion absorbed in the scale cover of the host was responsible for the lethal effect. Similar results were obtained with parasitized scale insects which were exposed in a commercial citrus grove to ground spray of malathion (1 · 3% malathion). An experiment with natural populations of both parasitoids in the citrus grove clearly demonstrated the susceptibility of A. holoxanthus to malathion-bait spray and were consistent with the above-mentioned laboratory experiments. The results are discussed in the light of the predominant status of P. smithi as a natural enemy of the Florida red scale in citrus groves in Israel. No delayed effects related to fertility, sex ratio and life expectancy of both parasitoid species which survived the malathion treatment were observed.

Population and cholinesterase responses in fish exposed to malathion sprays

A population of young walleye in a shallow pond in Winnipeg was exposed to malathion after two aerial applications of this pesticide for mosquito control. The population was sampled frequently throughout the season for survival and growth estimates, and also for brain cholinesterase measurements since that enzyme was known to respond to malathion poisoning. Cholinesterase activity fell to about 25% of prespray values within 12 hr after the first spray, and then gradually recovered to about 80% of prespray values over 2 weeks. The same pattern was evident after the second spray, but the inhibition of cholinesterase activity was not quite as large. Fish captured for analysis showed no indication of the symptoms of organophosphorus insecticide poisoning. There have been a number of reports published linking cholinesterase inhibition with lethal and sublethal responses in exposed groups, but we are unaware of previous cases in which strong cholinesterase inhibition has been observed in a field population for which growth and survival statistics were available. This case, then, offered an opportunity to evaluate the biochemical response in terms of population parameters. The population statistics indicated small temporary decreases in both catch per unit effort and weight gains after the first spray. Evidently a reduction in cholinesterase activity to about 25% of preexposure levels was the approximate threshold for population effects.

Genetic linkage between malathion and dieldrin resistance in Anopheles arabiensis.

A strain of Anopheles arabiensis resistant to both malathion and dieldrin was crossed and backcrossed to a susceptible strain. The progeny were tested on each insecticide in turn. Less than 50% mortality in the second insecticide exposure among the backcross progeny indicated linkage between the resistance genes. In a backcross of A. gambiae X A. arabiensis hybrids a recombination rate of 7.5% was observed. A Y-translocation strain of A. arabiensis showed less than 2.8% recombination between the resistance genes. It is impossible to confirm the genotype of apparent recombinants using existing stocks, but the two resistance mechanisms are biochemically distinguishable. If the two genes are very closely linked, linkage disequilibrium could influence the consequences of switching to malathion spraying after dieldrin resistance has evolved.

Pediatric Skin Disease in Pakistan: A Study of Three Punjab Villages

The population of children younger than 5 years old in three widely distributed villages in Punjab, Pakistan, was examined for skin disease in November 1980. Approximately 29% of the children had infectious skin disease, with pyoderma the predominant diagnostic category. There were significant differences in pyoderma prevalence rates between villages, with the suppressive effect of malathion spraying for malaria control on the insect population representing the most likely explanation for the observed differences. These data again emphasize the amount of skin disease, particularly in children, in rural areas of the lesser developed countries, and the desirability of focusing attention on the dermatologic needs of this vast sector of the world's population.

Chemical Control of the Cypress Twig Gall Midge, Taxodiomyia cupressiananassa in Central Illinois

One to 4 foliar sprays of diazinon, dimethoate (Cygon), and malathion were made at 10 day intervals beginning May 16 to control the cypress twig gall midge on bald cypress trees in central Illinois. Three applications of dimethoate gave best control. All sprays were phytotoxic, with dimethoate causing the least noticeable injury.

Comparison of Fenitrothion and Malathion for Treatment of Plywood and Galvanized Steel Surfaces for Control of the Red Flour Beetle (Coleoptera: Tenebrionidae) and the Rusty Grain Beetle (Coleoptera: Cucujidae)1

Fir plywood and galvanized steel panels were treated with either 0.25 or 0.50 g AI/m2 of fenitrothion or malathion spray. Panels were stored at 25 :± 2°C and bioassayed after 1, 2, 4, 8, 16, and 35 weeks with adult Tribolium castaneum (Herbst) or adult Cryptoleste ferrugineus (Stephens) using exposure periods of 1, 3, or 6 hat 30 ± 1°C, 75: t 2% RH. Insect mortality observed 3 days after exposure to insecticide was considerably higher than was knock-down immediately at the end of the exposure periods. Over 35 weeks, malathion was significantly more toxic than fenitrothion at 0.50 g AI/m2, The type of surface did not affect the relative toxicity of the chemicals except that with malathion at 0.50 g AI/m2,C. ferrugineus mortality was significantly higher on steel than on plywood. The uptake of both insecticides by rapeseed adjacent to steel surfaces was more rapid and resulted in higher residue levels than in seed adjacent to wood surfaces. Fenitrothion levels in rapeseed were consistently higher than were malathion levels. Malathion would be slightly more effective than fenitrothion for treatment of empty granaries at similar rates of application under the conditions studied.

Malathion percutaneous absorption after repeated administration to man

Prediction of exposure and toxic potential of pesticides such as malathion are routinely based upon acute exposure and single-dose percutaneous absorption determination. What has become obvious with pesticide exposure such as the malathion spraying for the medfly is that chronic daily exposure is the more relevant situation. Our objective was to determine the percutaneous absorption of chronically applied malathion in man and to compare chronic absorption to single-dose absorption. The experimental design was to first topically apply [ 14C]malathion to human male volunteers. This procedure was followed by repeated administration of nonradioactive malathion to the same site of application (ventral forearm). [ 14C]Malathion was reapplied (Day 8) when urinary excretion of radioactivity from the first application reached minimum detectable levels. The first [ 14C]malathion absorption was compared to the second [ 14C]malathion application. The percutaneous absorption from the first [ 14C]malathion application was 4.48 ± 1.3% (SD) of the applied dose. The absorption from the second [ 14C] malathion administration was 3.53 ± 1.0%, a value not significantly ( p > 0.05) different from the first application. Therefore, for malathion the single-dose application data are relevant for predicting the toxic potential for longer-term exposure.

Tradescantia-Micronucleus (Trad-MCN) test on the genotoxicity of malathion.

The Tradescantia-Micronucleus (Trad-MCN) bioassay was utilized to determine the genotoxicity of Malathion, a common insecticide. Four different treatment procedures were applied: a) absorption of Malathion/water mixture (with or without DMSO and/or S-9) through the stem, b) spraying a Malathion/water mixture onto the plant cuttings in enclosed chambers, c) spraying a Malathion/water mixture on an open population of plants in the greenhouse, and d) absorption of Malathion fumes through the leaves and buds. Most treatments were administered for 6 hr, followed by a 24-hr recovery time. Slides were prepared from the samples and scored for micronucleus (MCN) frequencies. Results of 16 experiments indicated that the genotoxicity of liquid Malathion absorbed through the stem was very low and often masked by high toxicity, causing dead cells in the stem, leaves, and meiocytes. Malathion spray at the dosage of 0.435% in an enclosed chamber or on an open population of plants yielded negative responses. Malathion fumes at dosages of 0.15-0.25% induced significantly higher (0.05) MCN frequencies above the controls and altered the nuclear structure to form unequal sized nuclei and multiple breaks in each of the four cells of a tetrads. It also caused degeneration of nuclei, "protrusions on nuclei," and inhibition of cell growth. Higher dosages (above 0.25%) were toxic.

The dispersal and survival of Anopheles Culicifacies Giles (Diptera: Culicidae) in a Sri Lankan village under malathion spraying

AbstractTwo mark-release-recapture experiments with Anopheles culicifacies Giles were carried out immediately before and one month after a round of malathion spraying of houses (at 2 g/m2) in a village in north-western Sri Lanka. In the first experiment the measurement of bidirectional movement of females collected in two halves of the village showed that movement was somewhat affected by wind direction; the percentage of migrants moving partially upwind was greater (11·4) than that in the reverse direction (6·4). The best estimates of daily survival were 0·79 before spraying and 0·44 after spraying; population sizes were about 44 500 and 1300, respectively. The proportion of females resting in the collection huts rose after spraying. The results are discussed with reference to the evolution of insecticide resistance in populations under insecticidal pressure and those populations not selected by spraying.