GABA靶标杂环杀虫剂FIPRONIL对卫生害虫的活性研究

目的 :研究作用机制独特的新型杂环杀虫剂FIPRONIL对蚊、蝇、蠊 3种卫生害虫的活性 ,评价其在卫生害虫防制领域中应用的实际意义。方法 :微量点滴法、浸液法、药膜法、密闭圆筒喷雾法。结果 :FIPRONIL对淡色库蚊、家蝇及德国小蠊的致死性均优于拟除虫菊酯中的两种代表性杀虫剂氯菊酯和胺菊脂 ,击倒性则反之。对淡色库蚊幼虫的LC50 为 0 .0 1162 ppm ,对家蝇、德国小蠊的LD50 分别为 0 .0 0 371、0 .0 0 377μg/虫。结论 :FIPRONIL具备对 3种卫生害虫的高效毒力及无交互抗性的独特作用机制 。

GABA靶标杂环杀虫剂FIPRONIL对卫生害虫的活性研究

研究新型杂环杀虫剂FIPRONIL对蚊蝇蟑三种卫生害虫的活性 ,评价其在卫生害虫防治领域中应用的实际意义。结果表明 ,FIPRONIL对于淡色库蚊、家蝇及德国小蠊 ,致死性均优于拟除虫菊酯中两种代表性杀虫剂———致死型杀虫剂氯菊酯与击倒型杀虫剂胺菊脂 ,击倒性则反之。对淡色库蚊幼虫LC5 0为 0 0 116 2ppm ,对家蝇LD5 0为 0 0 0 371μg/虫 ,对德国小蠊LD5 0为 0 0 0 377μg/虫。FIPRONIL由于对三种卫生害虫的高效毒力及无交互抗性的独特作用机制 。

超高效地下地上害虫防治新药──Fipronil

Ｆｉｐｒｏｎｉｌ是一种对许多类作物或非作物的地下及地上害虫具有优异防治效果的新型杀虫剂。Ｆｉｐｒｏｎｉｌ以１２０ｇ／１０￣４ｍ￣２剂量拖于土壤内，能有效防治玉米根叶甲、金针虫和地老虎；以２５—５０ｇ／１０￣４ｍ￣２喷雾可有效防治马铃薯甲虫、小菜蛾等多种咀嚼式口器害虫；以５０ｇ／１０ｍ￣２处理水稻可很好地防治螟虫、褐飞虱和稻水象甲。且对菊酯、有机磷、氨基甲酸酯及环戊二烯类农药无交互抗性，因此，Ｆｉｐｒｏｎｉｌ对抗性害虫的防效甚佳。

Degradation of Chlorpyrifos and Fipronil in Rice from Farm to Fork and Risk Assessment

Degradation of pesticide residues （chlorpyrifos and fipronil） in rice from farm to fork and risk assessment for human health were studied to reveal the magnitude of risks faced by different populations of interest, so that appropriate measures can be taken to control the risks, and to refine and update the human health risk assessment data while helping to determine the maximum residue level （MRL） value and harvest interval. Different dosages and treatments were used in field trials for the harvest residue test. Residue levels of postharvest-applied chlorpyrifos and fipronil during storage, exposure to sunlight, washing and boiling processes （boiled rice） were investigated for brown rice. The dietary exposure evaluation model （DEEM） was employed to estimate acute and chronic risks faced by different populations of interest. Percent of reference dose （POR） and margin of exposure （MOE） were calculated. A positive correlation between pesticide residues and the dosage and application frequency of pesticide was found in the field trials. Risk quotients indicate that multiple applications and double dosages of chlorpyrifos increase the risks to the entire population and prolong exposures to toxic concentrations. The concentration of pesticide residues decreased as a function of time, after sunlight exposure, storage, washing, and boiling processes. 91.6 and 96.16% degradations were achieved at the end of the experimental period for fipronil and chlorpyrifos, respectively. The boiling process played an important role in the degradation of these pesticides. The result of risk assessment to human health showed that harvest residues of chlorpyrifos in rice and acute dietary risks of chlopyrifos were of concern. The acute dietary （food only） risk estimated for chlorpyrifos as percent of acute population adjusted dose （aPAD） was frequently over 100%. The risk faced by boys under the age of 14 was higher than that for girls of the same age. For the subpopulation above age 14, the risk reversed. The chronic dietary risk from food alone showed that dietary exposures with fipronil were below the level of concern for the entire population, including children. The risk faced by rural residents was more serious than that for urbanite residents with the most sensitive populations being children and male residents who faced higher acute dietary risk than the other subpopulation groups. The harvest interval was found to be the critical measure to mitigate risk for all populations for safe rice eating. All risk levels decreased to acceptable levels when the harvest interval was extended to 14 d. To address these risks, a number of measures including reduced application rates （should not be doubled at single application）, increased retreatment intervals （longer than 7 d） and extended interval of harvest （at least 14 d） will be needed. The MRL for fipronil in rice is recommended to be 0.01 mg kg 1 in accordance with Codex （ref）.

Preliminary Study on Resistance of the Rice Stem Borer (Chilo Suppressalis) to Fipronil

By means of topical application, fipronil resistance was surveyed in the rice stem borer, Chilo suppressalis, from 12 diferent areas in east China from 2001 to 2004. The rice stem borers in most regions of Jiangsu and Anhui were still susceptible to fipronil. But in Wuxi, Jiangsu Province and Cixi, Zhejiang Province, their sensitivity became decreased （resistance ratios were 3.1 and 3.6, respectively）, and the medium level of resistance （resistance ratio was 21.2） was found in Cangnan, Zhejiang Province. So, it was still at the early stage for fipronil resistance development in this pest. Synergism experiments showed that piperonyl butoxide（PBO） had a little effect on both susceptible and resistant borers （synergism ratios were 1.1-1.2）. Though triphenyl phosphate （TPP） and diethyl meleate （DEM） had no effect on the susceptible borers, they had significant synergism on fipronil in the resistant population to fipronil （synergism ratios were 1.8 and 1.6, respectively）, indicating esterase and glutathion S-transferase may be involved in the resistance mechanism. Bioassay with currently used insecticides indicated that triazophos （because of high resistance）, trichlorphon and acephate had very low toxicity to resistant borers. But diazinon, pyridaphenthion, decamethrin and avermeatin showed high toxicity and had no cross resistance to fipronil, which could be considered as substitute insecticides in the resistance managment.

Insecticide induction of O-demethylase activity and expression of cytochrome P450 genes in the red imported fire ant (Solenopsis invicta Buren)

The red imported fire ant （Solenopsis invicta） is a global major invasive pest, and has caused significant economic, social and environmental impacts since its invasion to mainland of China in 2004. To date, chemical control has been the most effective measure. However, the long-term use of chemicals would lead to an unexpected rebound. To understand the risks and explore the mechanisms of detoxification or induction to insecticides in S. invicta, the O-demethylase activity and expression of cytochrome P450 genes of workers and queens, and the effects of chlorpyrifos and fipronil exposure in workers were investigated. Biochemical assays showed the O-demethylase activity of cytochrome P450 was significantly higher in workers than in queens （1.66-fold）, and was significantly induced in workers exposed to chlorpyrifos and fipronil, reaching a maximum （3.00- and 1.95-fold） at 48 h and then decreasing dramatically compared to controls （exposed to acetone counter- part）. The relative expression levels of 12 cytochrome P450 expressed sequence tags （ESTs） in workers were significantly higher than in queens （from 2.3- to 36.4-fold）. Multiple cytochrome P450 genes （except 9E4） were co-up-regulated （from 1.5- to 2.86-fold） in workers exposed to fipronil. These results indicated that the increased O-demethylase activity may result from the increased transcription levels of cytochrome P450 related to detoxification of insecticides in S. invicta. It appears that cytochrome P450 plays an important role in enhanced metabolic detoxification of insecticides. At the same time, it also provides the theoretical basis for resistance management and rational usage of insecticides to control S. invicta.

Field Efficacy Test of 22% Fipronil FS against Sugarcane Stem Borers and Thrips

[ Objective] The paper was to explore the field efficacy of 22% fipronil FS against sugarcane stem borer and thrips （Baliothrips serratus Kobus ）. [ Method] The field trial was conducted by foliar spraying of 22% fipronil FS and mixed broadcasting with fertilizer in 2014. [ Result ] Foliar spraying of 22% fipronil FS at the dose of 50 mIV667 m~ had the best control effect against sugarcane stem borer, and the control effect at 90 d post administration was 70.70%, significantly higher than that of control agent （61.86%）. Medium and high dose of 22% fipronil FS had better control effects against sugarcane thrips. [ Conclusion ] Considering control effects against sugarcane stem borers and thrips as well as sugarcane yield, it is recommended that 22% fipronil FS is sprayed at medium concentration （50 mL/667 m2 ）.

Research Progress of Termite Control with Fipronil

The indoor and field control effect of fipronil against termite was introduced, and the main influencing factors were analyzed, including traverse transfer of fipronil between termite individuals, temperature and proportion of termite exposed to fipronil, synergistic effect of other agents on fipronil, diffusion and degrada- tion of fipronil in soil. The effects of fipronil and metabolites on environment were elaborated.

Lethality of Imidacloprid and Fipronil on Apis mellifera: A Retrospective Analysis on the French Case

The aim of this study was to draw a retrospective analysis on the lethality of Imidacloprid(Gaucho®)and Fipronil(Régent TS®)on Apis mellifera between 1992 and 2016 in France.Early monitoring reports in the 1992-2002 period notified these two embedded insecticides to be at the origin of massive colony collapse disorders.Ecotoxicological analyses based on the LD50 of Imidacloprid and Fipronil highlighted their differential lethality by both contact(Imidacloprid:81 ng/honeybee vs.Fipronil:5.9 ng/honeybee)and ingestion(Imidacloprid:3.7 ng/honeybee vs.Fipronil:4.2 ng/honeybee),but failed to point Imidacloprid’s high solubility as a higher lethal agent.Chemical properties and action mode of these two insecticides originated neural disfunction in the case of Imidacloprid,and honeybee brood immune depression for Fipronil.Despite the conduction of these monitoring reports and laboratory researches,Fipronil was completely banned in 2005 but Imidacloprid only in 2016.

Additive Efficiency of Fipronil + Methoprene Compared to Fipronil Alone against <i>Rhipicephalus sanguineus</i>Ticks in Naturally Infested Dogs

The acaricidal efficiency of fipronil alone and fipronil + methoprene compared to commercial fipronil and commercial fipronil + methoprene, applied by the epicutaneous route (spot-on) in dogs naturally infested with ticks, was assessed. Thirty dogs infested with high loads of ticks were used. On day 0, the dogs were divided into 5 groups of 6 animals each. Each animal was duly identified for individual and group monitoring. Treatments were made based on body weight according to manufacturer’s instructions. Group 1 (G1) received 10.0% fipronil at a single dose of a pipette applied by epicutaneous route in the base of the neck. G2 received 10% fipronil + 10% methoprene in single application similarly to G1. G3 was treated with 9.8% commercial fipronil as before mentioned. G4 received commercial 9.8% fipronil + 9.8% methoprene applied as in previous groups. G5 served as an infected untreated control. Animals were examined by thumb tick counts on days 0 (Treatment day), 3, 7, 14, 21 and 28. Efficacy was measured as a percentage of tick reduction in the treated groups relative to the untreated control. Results indicated an overall efficacy of 88.2%, 93%, 90.4% and 99.3%, respectively. There was no significant statistical difference between the treated groups (P < 0.05), neither in sex nor in weight. Engorged ticks were the most frequent, followed by the nymph group. However, by the end of the study these data were reversed due to the fact that only small larvae were found, which we interpreted came from engorged ticks that released their progeny before dying and a month later their offspring began to be observed presently and in full development. It is concluded that the combined formulations of fipronil + methoprene compared to fipronil applied alone, showed an additive effect against Rhipicephalus sanguineus ticks in naturally infested dogs kept in captivity.

Residual Effect of Fipronil in Eriocheir sinensis

The residual effects of fipronil aqueous solutions(at mass concentrations of 10,30 and 50μg/L,respectively)on Eriocheir sinensis were investigated by the semi-static experiment method.The results showed that among the treatment groups with different mass concentrations,the high mass concentration group contained fipronil at a significantly higher content in the crab legs than the low-mass concentration group,and also a significantly higher content in the body than the low mass concentration group.There were no significant differences in the content of fipronil between different parts of E.sinensis.The trend of fipronil-enriched parts was from the legs to the body to the gonads.Fipronil residue in E.sinensis had no sex selectivity,but it enriched faster in female E.sinensis than males.This study provides a certain reference for dealing with related fishery pollution accidents.

Comparative Efficacy of Three Commercial Ectoparasiticides against Fleas in Naturally Infested Dogs

Fleas that infest pets are considered important parasites of both animals and humans. These insects cause irritation and can also transmit zoonotic diseases. Research has led to a rapid expansion in the development of flea control products. In the face of a market that offers dozens of commercial ectoparasiticides for dogs and cats, pet owners and veterinarians must be provided with evidence to support their decision to select a product to control fleas. To compare the efficacy of three commercially available products against companion animal fleas, a trial was conducted on naturally-infested dogs in order to validate their pulicidal activity. Thirty-two flea-infested dogs with fleas were divided into 4 groups (n = 8) for each treatment. Group 1 received one pipette of permethrin as a spot-on dose of 650 mg/ml. The second group received 9.7% fipronil as a spot-on formulation. Group 3 was treated with a spot-on formulation of permethrin 7.40% plus piperonyl butoxide at 7.40%. Group 4 remained as the untreated control. Fleas of all experimental dogs were examined and counted on days 0, 3, 7, 14, 21 and 28 to determine the percentage of flea reduction. Results showed a 100% efficacy for all tested products. Identified species were: Ctenocephalides felis (75.7%), Ctenocephalides canis (15.9%) and Pulex irritans (9.5%). Based on these results, it was concluded that the three anti-flea products evaluated under the conditions of this study, produced an excellent efficacy as from the third day after treatment.

锐劲特(FIPRONIL)——一种大有希望的档案害虫杀虫剂

锐劲特(Fipronil)是法国罗纳普朗克公司的科学家1981年发现并历经11年的悉心研究推出的一种新型化学杀虫剂。现除了在农业领域得到广泛应用外,在畜牧业、公共卫生、动物健康等方面都得到了一定的应用。特别是正在开发的一些针对蟑螂、蚂蚁、白蚁、蠹甲等害虫的剂型,将把它逐渐地推入档案保护工作中来。因此,有必要将它介绍给广大的档案保护工作者。 1、锐劲特的理化性质 锐劲特是经国家标准局认可的该物质的通用名,其化学名为(士)-5一氨基-1-(2、6—二氯-α.α,

Development of an analytical method based on solid-phase extraction and LC-MS/MS for the monitoring of current-use pesticides and their metabolites in human urine

Pyrethroids,organophosphorus pesticides and fipronil have been listed as priority chemicals in human biomonitoring studies because of their wide use and potential health effects in humans.The determination of 13 pesticides,including pyrethroids(deltamethrin,cypermethrin,permethrin,cyfluthrin,bifenthrin),organophosphorus(chlorpyrifos,chlorpyrifosmethyl,and malathion),fipronil,neonicotinoids(imidacloprid,acetamiprid and thiacloprid)and triazole(prothioconazole),together with 13 corresponding metabolites in human urine samples was achieved by solid-phase extraction and analysis by liquid chromatography coupled to tandem mass spectrometry.All targeted compounds,except malathion dicarboxylic acid,were measured with a mean within-accuracy(n=5)of 71%–114%(RSD:1%–14%)and between-run(n=15)accuracy of 80%–118%(RSD:2%–14%).Limits of quantitation of the targeted analytes ranged from 0.1 to 16 pg/m L.The detection result of urine samples from 25 volunteers indicated that the detection frequencies of 3,5,6-trichloro-2-pyridinol(median:448 pg/m L),6-chloropyridine-3-carboxylic acid(median:193 pg/m L),2-methyl-3-phenylbenzoic acid(median:181 pg/m L),3-phenoxybenzoic acid(median:99 pg/m L),2-isopropyl-6-methyl-4-pyrimidinol(median:77 pg/m L),cyfluthrin(median:59 pg/m L),cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid(cis-DCCA,median:53 pg/m L),trans-DCCA(median:25 pg/m L),prothioconazole(median:21 pg/m L),imidacloprid(median:7 pg/m L),and prothioconazole-desthio(median:1 pg/m L)were>50%.The obtained results show that the validated method is suitable for the human biomonitoring of these currentuse pesticides and their metabolites.

Distinct roles of two RDL GABA receptors in fipronil action in the diamondback moth (Plutella xylostella)

The phenylpyrazole insecticide fipronil blocks resistance to dieldrin(RDL)γ-aminobutyric acid(GABA)receptors in insects,thereby impairing inhibitory neurotransmission.Some insect species,such as the diamondback moth(Plutella xylostella),possess more than one Rdl gene.The involvement of multiple Rdls in fipronil toxicity and resistance remains largely unknown.In this study,we investigated the roles of two Rdl genes,PxRdl1 and PxRdl2,in P.xylostella fipronil action.In Xenopus oocytes,RvRDL2 receptors were 40 times less sensitive to fipronil than P.vRDL1.P.vRDL2 receptors were also less sensitive to GABA compared with PxRDL1.Knockout of the fipronil-sensitive PxRdll reduced the fipronil potency 10-fold,whereas knockout of the fipronil-resistant PxRdl2 enhanced the fipronil potency 4.4-fold.Furthermore,in two fipronil-resistant diamondback moth field populations,PxRdl2 expression was elevated 3.7-and 4.1-fold compared with a susceptible strain,whereas PxRdl1 expression was comparable among the resistant and susceptible strains.Collectively,our results indicate antagonistic effects of PxRDLl and PxRDL2 on fipronil action in vivo and suggest that enhanced expression of fipronil-resistant PxRdl1 is potentially a new mechanism of fipronil resistance in insects.