Laboratory evaluation of toxicity of selected insecticides against egg and larval stages of cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

Background The cryptic nature of pink bollworm Pectinophora gossypiella(Saunders)larvae enables its reduced vul-nerability to insecticidal control.Further,the development of resistance against Bacillus thuringiensis(Bt)toxins posed a serious threat to transgenic cotton cultivation.This necessitated determining the critical timing of spray applications on the control effectiveness.This study assessed the influence of egg age(freshly laid vs.three-day-old)and the loca-tion of larvae(directly exposed to the insecticide residues on the boll rind vs.burrowed inside the bolls)on insecticide control efficacy.Results The results revealed a significant decrease in the ovicidal activity of tested insecticides with an increase in the age of eggs from one day old to three days old(paired t-test,P<0.05).The larvae directly exposed to the insec-ticide residues on the boll rind were more susceptible(>80%mortality)than the larvae exposed after they had bur-rowed inside the bolls(<49%mortality).The inhibitory effects of tested insecticides on developmental biology were more pronounced in the experiment on pre-larval release insecticide treatment compared with insecticide treatment given post-larval release and entry inside the bolls.Conclusion Egg age influences the insecticide susceptibility,as does the larval location,directly exposed vs bur-rowed inside the bolls.Older eggs and the larvae that had burrowed inside the green bolls of cotton were relatively less susceptible to the insecticide treatments.The toxic effects of insecticides on egg and larval stages were primar-ily ephemeral.These findings are significant for devising a comprehensive strategy for pink bollworm management on a sustainable basis.

Risk of control failure to insecticides malathion,profenophos+cypermethrin mixture,and fipronil in boll weevil(Coleoptera:Curculionidae)populations from Bahia,Brazil

Background To control the boll weevil Anthonomus grandis grandis(Coleoptera:Curculionidae),a key pest of cotton in the Americas,insecticides have been intensively used to manage their populations,increasing selection pressure for resistant populations.Thus,this study aimed to detect insecticide resistance and assess insecticide control failure likelihood of boll weevil populations exposed to malathion,profenophos+cypermethrin,and fipronil insecticides.Results Twelve populations of the boll weevil were collected from commercial cotton fileds of the state of Bahia,northeastern Brazil.These populations were exposed to malathion,profenophos+cypermethrin mixture,and fipronil,at their respective maximum label dose for field applications.Three replicates of 10 adult beetles were exposed to the insecticides and mortality was recorded after 24 h treatment.The control failure likelihood was determined after 48 h.Highest median lethal times(LT_(50))were observed for malathion and the profenophos+cypermethrin mixture.Resistance to at least one insecticide was detected in 11 populations;three populations were resistant to malathion and profenophos+cypermethrin;seven were resistant to all insecticides tested.The resistance levels were low(<10-fold)for the three insecticides.Among 12 populations tested,58%of them exhibited significant risk of control failure for the insecticides malathion and profenophos+cypermethrin.The insecticide fipronil was efficient for the control of the boll weevil in 83%of the populations.Conclusions The results confirm the significant risk of insecticide control failure in the boll weevil populations to the main compounds used in the region.Thus,proper insecticide resistance management plans are necessary for the boll weevil in the region,particularly for malathion and profenophos+cypermethrin insecticides.

Evaluation of the Efficacy of an Aloe barbadensis Based Biological Insecticide against Pests of Abelmochus esculentus for Promoting Ecological Agriculture (Far-North, Cameroon)

Chemical insecticides have been considered as a means to combat crop pests. Although their effectiveness is evident, their impact on the environment is increasingly being discussed. The aim of this study is to determine the agro-ecological potential of a biological insecticide (C25H32O12) based on Aloe barbadensis in a Sahelian context. For this purpose, a completely randomized block experimental design with 3 replications and 4 treatments was set up to experiment with Aloe barbadensis as a bioinsecticide against pests of Abelmoschus esculentus. However, data were collected using an observation and parameter monitoring grid. This includes the cultivation of Abelmoschus esculentus, soil preparation, seeding and watering, plot labeling, preparation of the bioinsecticide (selection and preparation of raw materials, grinding of Aloe barbadensis miller and extraction of the crude bioinsecticide, quantification of treatment doses and dilution, and obtaining the formulated bioinsecticide), plant watering, plant treatment, and finally parameter monitoring. The results obtained reveal that the level of damage is significantly high in the control treatment T0 (63%) compared to the other treatments, with 29% for treatment T1, 7% for T2, and 1% for T3, implying a strong action capability of this insecticide against pests of Abelmoschus esculentus. Therefore, it can be concluded that for a normal growing season of Abelmoschus esculentus, this biological insecticide should be sprayed 12 times. Furthermore, this biological insecticide is unique in that it does not inflict any gastric toxicity on the pests, which gives it the characteristic of being a repellent. It is a biological insecticide whose efficacy period has been tested, with a minimum duration of 21 days. In conclusion, this formulated bioinsecticide based on Aloe barbadensis demonstrates significant efficacy against pests of Abelmoschus esculentus. In the future, we will consider experimenting with its effectiveness against pests of other plants.

Security and Privacy in Solar Insecticidal Lamps Internet of Things:Requirements and Challenges

Solar insecticidal lamps(SIL) can effectively control pests and reduce the use of pesticides. Combining SIL and Internet of Things(IoT) has formed a new type of agricultural IoT,known as SIL-IoT, which can improve the effectiveness of migratory phototropic pest control. However, since the SIL is connected to the Internet, it is vulnerable to various security issues.These issues can lead to serious consequences, such as tampering with the parameters of SIL, illegally starting and stopping SIL,etc. In this paper, we describe the overall security requirements of SIL-IoT and present an extensive survey of security and privacy solutions for SIL-IoT. We investigate the background and logical architecture of SIL-IoT, discuss SIL-IoT security scenarios, and analyze potential attacks. Starting from the security requirements of SIL-IoT we divide them into six categories, namely privacy, authentication, confidentiality, access control, availability,and integrity. Next, we describe the SIL-IoT privacy and security solutions, as well as the blockchain-based solutions. Based on the current survey, we finally discuss the challenges and future research directions of SIL-IoT.

The Entomological Efficacy of Piperonyl Butoxide (PBO) Combined with a Pyrethroid in Insecticide-Treated Nets for Malaria Prevention: A Village-Based Cohort Study Prior to Large-Scale Deployment of New Generation Mosquito Nets in Burkina Faso

The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that incorporate synergistic components, such as piperonyl butoxide (PBO). The purpose of this study is to provide entomological evidence for the efficacy of a PBO-based ITN brand at the village level, serving as a basis for decision-making before large-scale net deployment. During the high malaria transmission period, ITNs were distributed in each group and vector sampling was conducted biweekly in selected households. Bionomic data were collected to assess the resistance of wild An. gambiae populations to various chemical insecticides. There was a significant disparity in total An. gambiae sl. collected between the ITN arms, the intervention arm (ITN arms), and the control arm (P = 0.003). An. coluzzi was identified as the predominant species in the study area, as confirmed by PCR analysis. Analysis of the blood-feeding inhibition rate revealed that 100% permethrin + PBO ITN exhibited significantly greater inhibition than 66.81% permethrin only ITN. According to the log-time probit regression analysis, permethrin exhibited a knockdown time of 256 min without synergists, while it decreased to 139 min (P = 0.001) when pre-exposed to PBO. The evidence from this trial supports the use of PBO ITNs over standard ITNs for pyrethroids to combat pyrethroid resistance and improve protection against malaria for both individuals and communities, particularly in areas with high pyrethroid resistance.

Susceptibility of Different Populations of Nilaparvata lugens from Major Rice Growing Areas of Karnataka, India to Different Groups of Insecticides

Susceptibility to insecticides was investigated by collecting field populations of brown planthopper from different locations of southern Karnataka, India （Gangavati, Kathalagere, Kollegala, Soraba and Mandya）. All the field populations differed in their susceptibility to insecticides. In general, Soraba and Mandya populations were more susceptible to insecticides compared to Gangavati and Kathalagere populations. The resistance ratios varied greatly among the populations viz., chlorpyriphos （1.13- to 16.82-fold）, imidacloprid （0.53- to 13.50-fold）, acephate （1.34- to 5.32-fold）, fipronil （1.13- to 4.06-fold）, thiamethoxam （1.01- to 2.19-fold）, clothianidin （1.92- to 4.86-fold）, dinotefuran （0.82- to 2.22- fold）, buprofezin （1.06- to 5.43-fold） and carbofuran （0.41- to 2.17-fold）. The populations from Gangavati Kathalagere and Kollegala exhibited higher resistance to some of the old insecticides and low resistance to new molecules.

Insensitive Acetylcholine Receptor Conferring Resistance of Plutella xylostella to Nereistoxin Insecticides

The combinative rate measurement of （3-[I125] iodotyrosyl） α-bungarotoxin was applied in the analysis of the relation between nerve acetylcholine receptor and three types of insecticide resistance in diamondback moth, Plutella xylostella （L.）. In the dimehypo-resistant strain and in the cartap-resistant strain, the nerve acetylcholine receptor showed the remarkable insensitivity to dimehypo and cartap, of which the binding rate to ligand was approximately 66 and 60%, respectively, of the susceptible strain. The sensitivity to deltamethrin in the deltamethrin-resistant strain did not show visible change. These results indicated that the decline in the sensitivity of nerve acetylcholine receptor to insecticide might be a potential mechanism to nereistoxin insecticides resistance in the diamondback moth.

Susceptibility of Anopheles maculipennis to different classes of insecticides in West Azarbaijan Province, Northwestern Iran

Objective: To determine the susceptibility status of Anopheles maculipennis(An. maculipennis) against the major insecticides used in the health sectors in West Azarbaijan Province, Northwestern Iran.Methods: Unfed 3-5 days old adult females of An. maculipennis were collected across the West Azarbaijan Province and were subjected to evaluation of their susceptibility following World Health Organization recommended protocol against six insecticides(permethrin, deltamethrin, propoxur, bendiocarb, malathion and dieldrin) belonging to four different classes. Results: In this study, 916 specimens of An. maculipennis were examined against the insecticides which indicated that An. maculipennis was tolerant to permethrin, deltamethrin and dielderin, but displayed resistance against propoxur, bendiocarb and malathion. Conclusions: The pattern of resistance in An. maculipennis could be attributed to the agricultural landscapes, agricultural pesticides used and the exposure of the mosquitoes to insecticides. Logical cooperation is needed between the agriculture and health sectors to ensure the judicious use of pesticides in each sector and the management of probable resistance.

Resistance status of main malaria vector, Liston (Diptera:Culicidae) to insecticides in a malaria Endemic Area,Southern Iran

Objective: To evaluate the susceptibility of Anopheles stephensi(An. stephensi) Liston, the main malaria vector in southern Iran, to WHO recommended insecticides. Methods: Larvae of An. stephensi were collected from three different larval habitats in both urban and rural area of Bandar Abbas city and one rural area in Rudan county southern Iran. WHO standard method was used for evaluation of adult and larval mosquito susceptibility. Bendiocarb, permethrin, lambda-cyhalothrin, deltamethrin as insecticide and temephos and chlorpyriphos as larvicide were used at the diagnostic dosages recommended by WHO. Results: Findings of this study showed all larval populations of An. stephensi were completely susceptible to temephos and candidate for resistance to chlorpyriphos. Adult mosquitoes in rural areas of Bandar Abbas city were resistant to pyrethroid and carbamate insecticides. Conclusion: Comparison of the results of this survey with previous studies indicates that the resistance to pyrethroids and carbamates in this malaria endemic region is increasing. Wide use of pesticides in agriculture is certainly effective in increasing resistance. The inter-sectoral coordination and collaboration in health and agriculture seem to be necessary to manage insecticide resistance in malaria vectors.

Bemisia tabaci Biotype Dynamics and Resistance to Insecticides in Israel During the Years 2008-2010

The sweetpotato whitefly Bemisia tabaci（Hemiptera：Aleyrodidae）is an extremely polyphagous insect pest that causes significant crop losses in Israel and worldwide.B.tabaci is a species complex of which the B and Q biotypes are the most widespread and damaging worldwide.The change in biotype composition and resistance to insecticide in Israel was monitored during the years 2008-2010 to identify patterns in population dynamics that can be correlated with resistance outbreaks.The results show that B biotype populations dominate crops grown in open fields,while Q biotype populations gradually dominate crops grown in protected conditions such as greenhouses and nethouses,where resistance outbreaks usually develop after several insecticide applications.While in previous years,Q biotype populations were widely detected in many regions in Israel,significant domination of the B biotype across populations collected was observed during the year 2010,indicating the instability of the B.tabaci population from one year to another.Reasons for the changing dynamics and the shift in the relative abundance of B.tabaci biotype,and their resistance status,are discussed.

A Review of Agricultural Pesticides Use and the Selection for Resistance to Insecticides in Malaria Vectors

Most national malaria control programmes rely extensively on pyrethroid insecticides to control mosquito vectors of this disease. Unfortunately, the intensive use of this class of insecticides both in public health and agriculture has led to its reduced efficacy. The objective of this review was to assess the role of agricultural pesticides use on the development of resistance to insecticides in malaria vectors and the potential impact of this resistance on control activities. We searched library catalogues and public databases for studies that included data on resistance to the major classes of insecticides: organochlorines, carbamates, organophosphates and pyrethroids, in the malaria vectors of Anopheles genera. There is a strong geographical bias in published studies many originating from West African countries. Several studies demonstrate that resistance to pyrethroids is widespread in the major malaria vectors of the Anopheles gambiae and Anopheles funestus complexes. Assessing the impact of insecticide resistance on vector control is complicated owing to the lack of studies into the epidemiological consequences of resistance on the control of malaria and other vector borne diseases.

Irritability of malaria vector,Anopheles sacharovi to different insecticides in a malaria-prone area

Objective:To determine the susceptibility and irritability level of malaria vector Anopheles sacharovi(An.sachrovi) to different insecticides in a malaria-prone area.Methods:Susceptibility and irritability levels of field collected strain of An.sacharovi to WHO standard papers of DDT 4%,dieldrin 0.4%,malathion 5%,fenitrothion 1%,permethrin 0.75%,and deltamethrin 0.05% were determined in East Azerbaijan of Iran during reemerging of malaria as described by WHO.Results:Results showed that at the diagnostic dose of insecticides this species exhibited resistance to DDT,tolerant to dieldrin and but somehow susceptible to fenitrothion,malathion, permethrin and deltamethrin.The results of irritability of this species to DDT,lambdacyhalothrin. permethrin cyfluthrin and deltamethrin revealed that DDT had had the most and deltamethrin the least irritancy effect.The average number of take offs/fly/minules for DDT was 0.8±0.2.The order of irritability for permethrin,lambdacyhalothrin,cyfluthrin and deltamethrin were 0.7±0.2,0.5±0.2, 0.5±0.3,and 0.2±0.1,respectively.Conclusions:Results of this study reveals the responsiveness of the main malaria vector to different insecticides.This phenomenon is depending on several factors such as type and background of insecticide used previously,insecticide properties,and physiology of the species.Careful monitoring of insecticide resistance and irritability level of species could provide a clue for appropriate selection of insecticide for malaria control.

Pharmacophore model for neonicotinoid insecticides

An effective prediction pharmacophore model （RMS = 0.634, Correl = 0.893, Weight = 1.463, Config = 11.940） was successfully obtained by 3D-QSAR based on a series of nAChR （nicotinic acetylcholine receptors） agonists, which consists of a hydrogen- bonding acceptor, a hydrogen-bond donor, a hydrophobic aliphatic and a hydrophobic aromatic centre. This pharmacophore model may provide theoretical basis for designation and development of higher active insecticides.

Toxicity of Five Insecticides to Culicoides oxystoma Kieffer (Diptera:Ceratopogonidae)

Field-collected Culicoides oxystoma adults were exposed to different concentrations of commercial insecticides including chlorpyrifos, DDVP, deltamethyrin, beta-cypermethrin and beta--cypermethrin · emamectin benzoate via filter paper method, to determine toxicity of different insecticides on C. oxystoma. Results showed that toxicities varied significantly among insecticides. Biting midges were the most susceptible to deltamethyrin （0. 060 mg/L）, followed by chlorpyrifos （0. 588 mg/L）, beta-cypermethrin （ 1. 741 rag/L）, beta-cypermethrin · emamectin benzoate （99.670 mg/L）, and DDVP （600. 496 mg/L）. After exposed to insecticides for 1 h, tested midges were transferred to recovery chamber and observed for another 24 h ; increased mortality within this period was different under different concentrations of each insecticide. Relative toxicity index of dehamethrin was maximal when used as the standard reagent.

Effect of Insecticides on <i>Trichogramma</i>Parasitoids Used in Biological Control against <i>Prays oleae</i>Insect Pest

This study investigated the direct effect of the insecticides deltamethrin and spinosad on three egg parasitoids species: Trichogramma oleae, T. cacoeciae and T. bourarachae. The parasitoid pupae were exposed to pesticide residues on fresh olive tree leaves at recommended concentrations (RC) at different time intervals: 3, 10, 17, 24 and 31 days after pesticide applications. Parasitism viability (% emergence from parasitized eggs) and adult emergence time (developmental time from pupa to adult emergence) were evaluated. Regarding to the International Organization of Biological Control (IOBC) guidelines, results of toxicity effects of insecticides show that: Deltamethrin was moderately harmful to all Trichogramma species at RC (Decis&reg;100 milliliters·ha&minus;1), however, spinosad was harmless to moderately harmful at RC (Tracer&reg;20 milliliters·ha&minus;1). Trichogramma species revealed differences with regard to adult emergence time and exhibited significant changes in parasitism viability with increasing time after pesticide treatment. While deltamethrin residues affected parasitism viability 31 days after the product application, spinosad displayed similar viability for almost species 24 days after the application. The usefulness of Trichogramma parasitoids used as biological control agents, in olive tree ecosystem, was discussed in integrated pest management programs for Prays oleae control when parasitoid species were exposed during pupal stage to the insecticide residue.

The Relationship Between Resistance to Controlled Atmosphere and Insecticides of Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)

The cross resistance of four resistant strains of Liposcelis bostrychophila Badonnel, an important stored-product insect pest, was investigated. These four strains included the HCO2-R (hypercarbia-resistant strain), HCLO-R (hypoxia and hypercarbia resistant strain), DDVP-R (DDVP-resistant strain) and PH3-R (PH3-resistant strain). The results indicated that there were cross-resistances between CA and insecticides, and the quantities of the cross-resistance were different. The cross-resistance factor (RF) of HCO2-R to hypoxia and hypercarbia was 3.2458, whilst, that of HCLO-R to hypercarbia was 1.8280. The RF of DDVP-R to PH3 was 3.9614, whilst, that of PH3-R to DDVP was 2.7852. The RF values of DDVP- R and PH3-R to hypercarbia were 1.3550 and 1.1816, respectively. However, the RF of HCO2- R to DDVP was 2.1372. There also was a low cross-resistance between DDVP-R and HCO2-R. The RF of HCO2-R to PH3 was 3.3698. This suggested that the insects resistant to high CO2 concentration atmosphere would develop significant resistance to PH3. However, the insects resistant to PH3 remain sensitive to hypercarbia atmosphere. Both DDVP-R and PH3- R developed resistance to high CO2 treatment. There was a low cross-resistance between DDVP-R and HCLO-R. The insects resistant to hypoxia and hypercarbia were very sensitive to DDVP. There also was cross-resistance between HCLO-R and PH3-R, but the resistance of PH3-R to hypoxia and hypercarbia was lower than that of HCLO-R to PH3. The difference of the overlapping and separate values indicated that there were differences in the intercross-resistance of four resistant strains.

Effect of heat shock on the susceptibility of Frankliniella occidentalis(Thysanoptera：Thripidae) to insecticides

Currently, insecticides are considered as the primary approach for controlling western flower thrips, Frankliniella occidentalis（Pergande）（Thysanoptera： Thripidae）. However, the heavy use of insecticides resulted in high insect resistance and serious environmental pollution. Given its characteristics of ease of operation and environmental friendliness, insect control using high temperature is receiving considerable renewed research interest. However, although the combination of insecticides and high temperature to control F. occidentalis has been studied before, few studies have focused on the short-term effect of such treatment. In a laboratory study, F. occidentalis adults and second-instar nymphs were exposed to 45℃ for 2 h. Then, their susceptibility to acetamiprid, spinosad, methomyl, and beta-cypermethrin was tested after different periods of recovery time（2–36 h）. Additionally, the specific activity of three detoxification enzymes（esterase, glutathione S-transferase, and cytochrome p450（CYP） monooxygenase） of the treated insects was determined. The results indicated that the fluctuation of susceptibility to insecticides and detoxification enzyme activity during F. occidentalis recovery from heat shock are related. Furthermore, several recovery time points（2, 30, and 36 h） of significant susceptibility to four tested insecticides compared with the control were found during the treatment of adults that were heat-shocked. Recovery time points of higher susceptibility compared with the control depended on different insecticides during the second-instar nymph recovery from heat shock. Interestingly, the fluctuation of CYP monooxygenase activity exhibited a trend that was similar to the fluctuation of susceptibility to insecticides（especially spinosad） during the recovery from heat shock of adults. In addition, the glutathione S-transferase and CYP monooxygenase activity trend was similar to the trend of susceptibility to spinosad during the recovery from heat shock of second-instar nymphs. Our results provide a new approach for controlling F. occidentalis using the combined heat shock and insecticide. This effectively enhances the control efficiency of heat shock and significantly reduces the application of insecticides.

Indoor Efficacy Experiment of 13 Insecticides against Tea Geometrid (Ectropis Oblique Hypulina Wehrli)

[Objective]The paper was to study indoor efficacy of 13 insecticides against tea geometrid（Ectropis Oblique Hypulina Wehrli）.[Method]Thirteen insecticides were sprayed onto indoor hydroponic young tea shoots with infesting third instar larvae of tea geometrid reared in the laboratory to simulate the actual condition in the tea garden,and their efficacy was studied.[Result]The control efficacies of 60 g/L spinetoram SC 3 000 times dilution,3% emamectin benzoate ME 15 000 times dilution,240 g/L methoxyfenozide SC 5 000 times dilution and 240 g/L metaflumizone SC 1 500 times dilution were all greater than 91% after spraying for 7d.The control efficacy of 20%tebufenozide SC 1 000 times dilution remained 86.48%.Although the control efficacy of 20%flubendiamide WDG 6 000 times dilution was slightly lower than the above five treatments,the dry weight of faeces was the second least,and its protection effect on leaves was only second to spinetoram.Therefore,60g/L spinetoram SC,3% emamectin benzoate ME,240 g/L methoxyfenozide SC,240 g/L metaflumizone SC,20% tebufenozide SC and 20% flubendiamide WDG were ideal insecticides that could be used rotationally to control tea geometrid in tea garden.The control efficacy of 10% bifenthrin EC 3 000 times dilution was only 23%,so the insecticide was not suitable for control against the pest.[Conclusion]The paper proposed an alternate insecticide for field control against tea geometrid.

Toxicity and Field Efficacy of Six Insecticides on Alfalfa Thrips (Thysanoptera: Thripidae)

Alfalfa thrips,especially the bird s-foot trefoil thrips(Odontothrips loti Haliday),is a major pest in the alfalfa field.Toxicity and field efficacy of 6 insecticides were determined by leaf disk in tube method and foliar spray,respectively.The results showed LC 50 values of chlorfenapyr 24%SC,lambda-cyhalothrin 5%EW,sulfoxaflor 22%SC,dinotefuran 20%SG,spinetoram 60 g/L SC and tolfenpyrad 30%SC to Odontothrips loti were 0.11,0.62,2.92,4.24,10.47 and 13.42 mg/L,respectively.The control effects of tolfenpyrad 30%SC,spinetoram 60 g/L SC,sulfoxaflor 22%SC,lambda-cyhalothrin 5%EW and dinotefuran 20%SG against alfalfa thrips were more than 80%after 1 d treatment,showing good readily availability.The control of spinetoram 60 g/L SC and dinotefuran 20% SG was 74.63% and 75.65% after 7 d treatment,showing a long persistence effect respectively.Therefore,spinetoram 60 g/L SC and dinotefuran 20% SG can be used as the first option to control alfalfa thrips.

Determination of trace amounts of chlorinated insecticides and fungicides in ginseng using capillary gas chromatography and ^(63)Ni electron capture detector

A method for the simultaneous determination of a series of chlorinated insecticides and fungicides as residues in ginseng is presented in this article. Pulverized samples are subjected to Soxhlet extraction with acetone-petroleum ether and the extract is partitioned between petroleum ether and aqueous sodium sulfate solution (2:98). The combined petroleum ether phase is cleaned up by sulfuric acid and analyzed by capillary gas chromatography using 63Ni electron capture detector. Recoveries from the different concentrations for 11 kinds of chlorinated insecticides and fungicides are between 92.40 and 103.7% with coefficients of variations ranged 1.22 and 9.53% without samples, and between 89.00% and 104.10% with coefficients of variations between 1.16% and 9.16% with samples. The detection limits are 0.2- 7.0 ng/kg.