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1.
The internal and external levels of topically applied soil insecticides, tefluthrin, terbufos and dieldrin, to 3rd-instar larvae of the southern corn rootworm, Diabrotica undecimpunctata howardi (Barber), were monitored over 48 h. Symptomology of poisoning with 10 times the dose of the larval 72-h LD90 for each chemical was observed over 48 h at various time points after treatment. Terbufos penetrated more rapidly than tefluthrin or dieldrin, although internal levels of tefluthrin and dieldrin had a longer-lasting plateau than terbufos. A 72-h LD30 treatment with tefluthrin resulted in faster penetration and also faster disappearance from the insect compared with the 10×72-h LD90 dose over a 48-h period. Recorded symptoms of poisoning included regurgitation of gut contents, defaecation and writhing and these are suggested to play an important part in voiding of the toxicants at lower (sub-lethal) treatment levels. The sub-lethal effects of tefluthrin are discussed with respect to likely pest behavioural changes, such as anorectic response, after field treatment of a crop. © of SCI.  相似文献   

2.
Coccinella septempunctata L. is one of the most abundant ladybird species in Greece, preying on several aphid species and other arthropods, of which many are pests of cultivated plants. These pests are usually controlled with chemical insecticides. During this process, however, beneficials are also exposed to pesticides. The development of Integrated Pest Management (IPM) programs against aphids requires the evaluation of the effects of insecticides on beneficial insects. We evaluated the LD50 of imidacloprid, acetamiprid, bifenthrin and deltamethrin on first, second, third and fourth instar larvae of C. septempunctata by topical application. Moreover, we studied their sublethal effects (LD10) on the development, weight and prey consumption of fourth instar larvae. The topical application bioassays showed that deltamethrin and bifenthrin were highly toxic to all larval instars, whereas imidacloprid and acetamiprid were less toxic to fourth instar larvae. The LD10 dose significantly affected, developmental time, adult weight and daily predation. These results show the importance of assessing potential effect of insecticides on C. septempunctata for developing effective IPM programs of aphids in Greece.  相似文献   

3.
The kinetics of accumulation and elimination of lethal doses of [14C]carbofuran in the hemolymph of the house fly suggest a one-compartment open model. Carbofuran in the hemolymph appeared to be in equilibrium with that in the tissues very soon after treatment.Following topical application of carbofuran, the rate of onset of symptoms of poisoning was correlated with the amount of carbofuran in the hemolymph, and the onset of convulsions only occurred after the concentration of carbofuran in the hemolymph reached μM levels. This value correlated well with neurobioassays of known concentrations of carbofuran perfused in saline onto the isolated thoracic ganglion.Following topical doses, carbofuran concentration in the hemolymph reached a peak within an hour and then gradually declined. At an LD60 dose, the initial decline in carbofuran concentration in the hemolymph over time was significantly slower than the decline after an LD10 dose, suggesting saturation kinetics.Hemolymph was collected from house flies for up to 3 hr following topical application of toxic amounts of carbofuran. Thereafter, hemolymph volume decreased and blood samples could not be collected. Curiously, hemolymph samples could be collected for 5 hr from house flies that were injected with toxic doses of carbofuran.  相似文献   

4.
Relative potency of eight compounds (four pairs of similar types) to adults and old larvae of three species of cyclorhaphous diptera was determined by injection, oral or topical application. The following points emerged from comparisons of equitoxic doses: (a) C. putoria was consistently more susceptible than L. sericata. M. domestica was more susceptible to organochlorines than either of the blowflies, but less susceptible to organophosphorus, carbamate or pyrethroid insecticides; (b) the most potent insecticides (bioresmethrin, diazinon) were about equally toxic to adults and larvae of all species; but some compounds (especially DDT, gamma-BHC and propoxur) were relatively much less effective against larvae; (c) LD50 values for oral treatments were higher than by injection, and those for contact treatments higher still. These “penetration factors” were highly correlated within each of the stages. This could be due to similarity in the cuticular barrier and (or) detoxication; (d) experiments with various synergistic compounds showed higher synergistic factors for larvae than adults (with DDT, bioresmethrin and propoxur). This probably indicates a more efficient detoxication system in the larvae, which is consistent with findings (b) and (c).  相似文献   

5.
山东省绿盲蝽田间种群对六种杀虫剂的敏感性监测   总被引：1，自引：0，他引：1  
为了解山东地区绿盲蝽对常用杀虫剂的敏感性变化情况,于2010—2012年采用玻璃管药膜法监测山东聊城、菏泽、滨州、德州地区绿盲蝽田间种群对马拉硫磷、毒死蜱、灭多威、丁硫克百威、联苯菊酯和氟虫腈等6种杀虫剂的敏感性。结果显示,相对于2009年的监测数据,2010—2012 年各地绿盲蝽种群对不同杀虫剂表现出不同程度的敏感性变化,但相对毒力比值均小于10倍。其中对毒死蜱、联苯菊酯的敏感性均未降低,菏泽种群表现为敏感性增强,相对毒力比值小于1。2011—2012年德州种群对丁硫克百威、灭多威和氟虫腈的敏感性降低,相对毒力比值大于3倍,其它种群敏感性变化不大,相对毒力比值均小于3倍。3年间菏泽种群对马拉硫磷的敏感性变化不大,相对毒力比值小于3倍,其它种群敏感性均有所降低。因此,毒死蜱、马拉硫磷、联苯菊酯、丁硫克百威等仍是山东棉区防治绿盲蝽的有效药剂。  相似文献   

6.
Some effects of DDT on the cockroach nervous system have been correlated with poisoning symptoms, using free-walking cockroaches with implanted electrodes. Experiments at 16.5°C and 32°C used LD95 doses and at 25°C, an estimated LD95. DDT had excitant actions on each nerve studied; cercal afferent and efferent neurones, and abdominal interneurones. The effects on the central nervous system became more marked as temperature was reduced, despite the smaller quantity of DDT employed, but the excitant actions on the peripheral nervous system were not quantified. It is suggested that the effects of DDT on the cockroach nervous system could account for the negative temperature coefficient of toxicity of DDT.  相似文献   

7.
A method is described for simultaneous recording of in-vivo nerve activity and toxicological symptoms from 6th-instar larvae of Spodoptera littoralis poisoned with insecticide. Topically applied doses (9 ng-180 μg insect?1) of cypermethrin induced hyperactivity, repetitive activity and bursting in the ventral nerve cord; these activities were associated with different stages of poisoning in the whole animal and are consistent with pharmacokinetic studies. Nerve activity continued long after the larvae appeared to be dead (i.e. up to 5-6 days), although microscopic examination of these larvae revealed that they were still capable of small movements. At the lower doses (up to the LD95) time to death was inversely proportional to dose. Death of the organism may be related to the number of neurones which are affected by the insecticide.  相似文献   

8.
Laboratory experiments were used to analyse the effect of two insecticides, dimethoate and cypermethrin, on prey capture, feeding and rate of development of the wolf spider Pardosa amentata. Though partly lethal doses (LD50 and LD10) were applied and a high proportion of surviving spiders suffered paralysis for one to two days, which could be fatal under field conditions, no negative effects on other investigated biological characteristics (including development and predation rates) of the surviving individuals were observed. With very low doses of cypermethrin, killing rate and feeding of females in the period between the final moult and egg-sac deposition were increased compared to untreated controls. This is the first evidence of enhanced performance due to an insecticide in a spider. The possibility of insecticide stimulation of predator population recovery after eradication by spraying is discussed. © 1998 SCI.  相似文献   

9.
The speed of toxic action of an insecticide is an indicator for control efficacy and has considerable practical importance. For agricultural pest control, fast-acting is an important feature for an insecticide to consistently reduce the amount of feeding damage. Butene-fipronil is a novel compound obtained via the structural modification of fipronil. However, information about the toxicity and speed of toxic action is still limited. In the present paper, we compared the toxic feature of butene-fipronil with seven other insecticides, of which imidacloprid and abamectin are slow-acting insecticides, and acephate, endosulfan, methomyl, α-cypermethrin and spinosad are fast-acting insecticides. We found that the contact and stomach toxicities of butene-fipronil were among the highest ever estimated to Leptinotarsa decemlineata and Drosophila melanogaster. The speed of toxic action of butene-fipronil was determined using median lethal time (LT50) at a dose (concentration) equivalent to LD80 values. For L. decemlineata, the values for butene-fipronil, imidacloprid, abamectin, acephate, endosulfan, methomyl, cypermethrin and spinosad were calculated to be 39.9, 36.5, 37.5, 20.2, 22.4, 23.8, 16.4 and 23.1 h, respectively. Those for D. melanogaster were 29.8, 31.5, 29.4, 14.0, 20.3, 18.1, 13.5, and 20.1 h, respectively. ANOVA analysis showed that butene-fipronil, imidacloprid, abamectin had similar LT50 values, whereas acephate, endosulfan, methomyl, spinosad and cypermethrin had comparable LT50 values. Thus, butene-fipronil belongs to slow-acting insecticides. Our results provide more empirical information for butene-fipronil potential application.  相似文献   

10.
Effects of three insecticides, diazinon, fenitrothion and chlorpyrifos on Andrallus spinidens Fabricius (Hemiptera: Pentatomidae), a predator of lepidopterous larvae in rice fields were investigated. The insecticides were applied topically at lethal dose (LD30) on the fifth instar nymphs of A. spinidens and evaluated on life table and some biochemical parameters of the predatory bugs. The results showed that pre-oviposition period, fecundity and longevity of treated bugs were significantly affected compared with the control. Analysis of life table parameters of A. spinidens revealed adverse effects of insecticides on net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), doubling time (DT) and mean generation time (T). Among the tested insecticides, fenitrothion was the most toxic insecticide. The lowest value of r was 0.060 day?1 in fenitrothion. Effects of insecticides on the detoxification enzymes showed that all compounds had inhibitory effect on esterases, acetylcholinesterases and glutathione S-transferases. According to this study, the insecticides cause harmful effects on demographic and biochemical parameters of A. spinidens and are not compatible with the predatory bug even at sublethal concentration.  相似文献   

11.
BACKGROUND: The codling moth, Cydia pomonella (L.), is one of the most important pests of apple worldwide. Use of insecticides for management of this insect has been extensive and has resulted in resistance development. There are a number of different bioassay methods to monitor for codling moth resistance; however, many are not applicable to new insecticides and most are time consuming. A novel 16‐well plasticware bioassay plate containing lyophilized diet was developed for rapid resistance monitoring of codling moth. RESULTS: The contact insecticides acetamiprid and azinphosmethyl were significantly more toxic to neonates than to fourth instars. However, there was no significant difference in LC50 values between neonates and fourth instars to the ingestion insecticides chlorantraniliprole, methoxyfenozide, novaluron and spinetoram. Field colonies of codling moth were significantly more resistant to methoxyfenozide than susceptible populations. A diagnostic dose of 20 µg mL?1 (LC99) was established to monitor for codling moth resistance to methoxyfenozide. CONCLUSIONS: The results presented here demonstrate that a novel and rapid bioassay can be used to monitor for codling moth resistance to methoxyfenozide. The bioassay method is relevant to both ingestion and contact insecticides, but a single diagnostic dose, regardless of larval age, is only relevant to ingestion insecticides. Age‐dependent diagnostic doses are likely necessary for contact insecticides. Copyright © 2011 Society of Chemical Industry  相似文献   

12.
五种杀虫剂对蜜蜂的经口毒性及风险评价   总被引：6，自引：1，他引：5  
分别采用"小烧杯法"和"饲喂管法" 检测了50%虫螨腈水分散粒剂(WG)、1%甲氨基阿维菌素苯甲酸盐乳油(EC)、80%氟虫腈水分散粒剂(WG)、50 g/L氟虫腈悬浮剂(SC)、10%阿维菌素·哒螨灵乳油(EC)5种杀虫剂对蜜蜂工蜂的经口毒性。其中, "小烧杯法"测得的48 h LC50值分别为21.3、0.490、0.112、0.075 7、0.488 mg/L, "饲喂管法"测得的48 h LC50值分别为134、0.730、1.33、0.668、1.54 mg/L。就这5种杀虫剂而言,"饲喂管法"测得的48 h LC50值均不同程度高于"小烧杯法"。以摄入量计,则"饲喂管法"测得的48 h LD50值分别为1.34、0.007 30、0.013 3、0.005 37、0.015 4 μg/蜂。按毒性等级标准划分, 50%虫螨腈WG对蜜蜂具有中等毒性,1%甲氨基阿维菌素苯甲酸盐EC、10%阿维菌素·哒螨灵EC、80%氟虫腈WG和50 g/L氟虫腈SC对蜜蜂为剧毒。如果采用危害商值(Hazard Quotient,HQ)衡量药剂的风险性,则上述5种杀虫剂对蜜蜂的HQ值分别为84.0、205、3 247、3 609、8 939,表明它们对蜜蜂均具有潜在风险。同时还就两种检测方法的优缺点和适用范围进行了比较。  相似文献   

13.
BACKGROUND: The efficacies of organophosphate pesticides, single‐compound versus multicompound pyrethroid formulations and relatively novel unclassified insecticides/acaricides were compared to find the lowest dosage and highest efficacy for the control of Dermatophagoides farina (Hughes), D. pteronyssinus (Trouessart) and Tyrophagus putrescentiae (Schrank). Formulated active ingredients (AIs) were diluted in water and applied onto filter paper in experimental chambers with ten unsexed adult mites in six replicates. Mite mortality was checked after 24 h. The security index (SI) was calculated for all of the AIs by dividing the recommended rate by the LD90 determined for each species. RESULTS: The tested organophosphates had high LD90 and low SI values. The single‐compound pyrethroids were ineffective (deltamethrin and beta‐cyfluthrin) or had high LD90 and low SI values (cyphenothrin, permethrin, pyrethrum and bifenthrin). The multicompound miticides had low LD90 and high SI values which increased from deltamethrin/S‐bioallethrin to permethrin/S‐bioallethrin/piperonyl butoxide to permethrin/pyriproxyfen/benzyl benzoate. Abamectin, pyridaben, propargite and flufenoxuron were highly active against Dermatophagoides spp. Neem (Acarosan duo) was highly active against all mite species tested. CONCLUSION: The available formulations of multicompound pyrethroids (permethrin/S‐bioallethrin/piperonyl butoxide, permethrin/pyriproxyfen/benzyl benzoate), benzyl benzoate, neem and some field acaricides are effective in suppression of synanthropic mites in laboratory assays. Their LD90 are lower than those of traditionally used organophosphates or single‐compound pyrethroid formulations. Copyright © 2011 Society of Chemical Industry  相似文献   

14.
Sesquiterpene lactones, natural constitutents of the Asteraceae, are toxic to the grasshopper, Melanoplus sanguinipes, when injected into the hemocoel at doses greater than 0.25 μmol/300 mg insect. Dose-dependent sublethal symptoms range from a slight reduction in normal locomotory ability to severe locomotory impairment or paralysis, leading to death. The symptoms appear to be irreversible. Of the four compounds subjected to dose-response testing, parthenin was the most toxic with and LD50 in adult male grasshoppers of 0.55 μmol/insect. Structure-activity relationships for four of the six lactones tested indicate that compounds containing a cyclopentenone ring are equitoxic to males and females, whereas those lacking this functional group are approximately 4 × more toxic to males than females. In contrast to their sensitivity to injected lactones, adult male grasshoppers can tolerate ingestion or topical administration of up to 4 μmol of these compounds without any adverse effects. These results suggest that the integument and alimentary canal in this species provide effective barriers limiting the bioavailability of sesquiterpene lactones to the hemolymph in nature. Possible target sites and mechanisms-of-action for sesquiterpene lactones (once in the bloodstream) are discussed.  相似文献   

15.
The tomato borer, Tuta absoluta (Meyrick), was first recorded in Turkey in August 2009 and rapidly became a serious pest in the Mediterranean and Aegean coastal regions in field and greenhouse grown tomatoes. Currently, insecticides are considered one of the major tools for the management of T. absoluta in Turkey. This study, investigated the efficacy of 7 different insecticides, against T. absoluta in laboratory bioassays. To determine the lethal concentration (LC) values and feeding activity of the larvae, tomato leaf parts mined by 1–3 day old L1 larvae were dipped into different insecticide concentrations. Mortality was recorded 5 days after insecticide treatments. Spinosad, chlorantraniliprole + abamectin or indoxacarb treatment resulted in 100% mortality with minimal or no feeding in all populations at their recommended doses of 120, 50.4 and 60 mg a.s. L?1, respectively. In general, the LC99 values of populations for these insecticides were similar and also lower than that of the recommended field doses. The effect of pyridalyl was low, resulting in low mortality with serious feeding damage at the dose of 125 mg a.s. L?1. The efficacies of abamectin, metaflumizone and azadirachtin were found to be moderate to low at the recommended doses (4.5, 240 and 50 mg a.s. L?1, respectively). However, these insecticides may affect pupation and adult emergence rates hence further studies are recommended to investigate these insecticides.  相似文献   

16.
BACKGROUND: Cardamom, an important spice crop often attacked by many insect pests, is controlled mainly using synthetic insecticides. As honey bees play a vital role in pollination in cardamom, the impact of insecticides on honey bees needs to be explored to assess its safety. RESULTS: Risk assessment based on contact toxicity revealed diafenthiuron to be a non‐selective insecticide to bees with a low selectivity ratio (the ratio between the LD50 for beneficial and pest species). A dose of diafenthiuron that killed 90% of cardamom borer, Conogethes punctiferalis Guenee, was found to kill 100% of Indian bees. Based on the hazard ratio (the ratio between the field‐recommended dose and the LD50 for the beneficial), diafenthiuron was found to be slightly to moderately toxic to bees. Diafenthiuron, even at low concentrations of LC1 (the concentration that killed 1% of bees), was found to affect the foraging and homing behaviour of Indian bees. Of bees fed with 30 µg mL?1 of diafenthiuron, 40% were found missing on the third day after exposure. However, diafenthiuron did not affect bee visits to the cardamom fields. CONCLUSION: Diafenthiuron is more highly toxic to Apis cerana indica F. than to C. punctiferalis by contact, using selectivity ratio and probit substitution methods of risk assessment, but the hazard ratio revealed diafenthiuron to be a slightly to moderately toxic chemical. Diafenthiuron was found to affect the foraging and homing behaviour of bees at sublethal concentrations. Thus, sublethal effects are more relevant in risk assessment than lethal and acute effects. Copyright © 2010 Society of Chemical Industry  相似文献   

17.
The insecticidal properties of 1-(7-ethoxygeranyl)-2-methylbenzimidazole (EGMB) were investigated on larval and adult house flies. Unsynergised EGMB gave topical LD50 values of 0.53 μg per female fly on NAIDM strain house flies. When flies were pretreated with 5.2 μg piperonyl butoxide, susceptibility was increased (LD50 0.12 μg per female fly). House fly larvae were less susceptible to EGMB (LD50 2.2 μg). Poisoning with EGMB resulted in a rapid reduction in locomotor activity of both larval and adult house flies. This reduction in locomotion was progressive and led to complete paralysis. Various parameters of larval nervous system function were investigated in larvae during these early phases of poisoning. As early as 15 min after dosing larvae with LD95 doses of EGMB, sensory nerves were less responsive. Over a somewhat longer time (2–4 h), neurally evoked contractures were adversely affected by EGMB. In some cases, this effect appeared to be due to reduced postsynaptic potential amplitude; in other instances, it appeared to be due to an effect independent of neuromuscular transmission. The close temporal correlation between behavioural and electrophysiological observations suggests that the nervous and muscular systems are important sites of action of EGMB.  相似文献   

18.
Insecticide resistance inHelicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is one of the most important constraints on cotton production in Turkey. We investigated the susceptibility ofH. armigera strains collected from cotton fields in the Adana, Hatay and Antalya provinces to insecticides which are in wide use. LD50 values for tralomethrin, lambda-cyhalothrin, endosulfan, profenofos and methomyl were determined by topical bioassay. At the LD50 levels, resistance ratios for tralomethrin were 24.7-, 19.7- and 15.7-fold in the Adana, Hatay, and Antalya strains, respectively; and for lambda-cyhalothrin were 41-, 20-and 40-fold, respectively. Resistance ratios ranged from 1.2- to 2.1-fold in all field strains for endosulfan, profenofos and methomyl, with no significant resistance. These results suggest the presence of resistance to tralomethrin and lambda-cyhalothrin inH. armigera strains collected from cotton fields, but no resistance to endosulfan, profenofos or methomyl could be observed.  相似文献   

19.
BACKGROUND: The insecticides spinosad and deltamethrin are being increasingly used in pest management programmes. In order to assess further their toxic effects to target and non‐target insect species, an evaluation was made of their insecticidal profile on Bactrocera oleae (Rossi) and Drosophila melanogaster (Meig.). Moreover, possible genotoxic effects of the two pesticides were investigated using the somatic mutation and recombination test (SMART) in D. melanogaster. RESULTS: Both insecticides were highly effective against B. oleae, exhibiting similar LC50 values. Moreover, they were found to be more effective against Bactrocera than against Drosophila adults. However, spinosad was significantly more toxic than deltamethrin to D. melanogaster. The results showed a lack of genotoxic activity of both insecticides under the in vivo experimental procedure employed, at least at applied doses. CONCLUSION: The present study provides information for lethal and sublethal effects of spinosad and deltamethrin against a target and a non‐target species. Both insecticides can exert high toxicity to B. oleae when adults are exposed even to very low doses for long periods of time. The results contribute to the database on the genotoxic potential of spinosad and deltamethrin, suggesting a safety profile for both insecticides. Copyright © 2011 Society of Chemical Industry  相似文献   

20.
为筛选防治农业新发害虫双委夜蛾Athetis dissimilis（Hampson）的有效药剂,采用浸叶法测定了其不同龄期幼虫对8类18种常用杀虫剂的敏感性,并观察了幼虫对不同药剂的中毒症状。结果表明:3~6龄双委夜蛾幼虫对辛硫磷、联苯菊酯、高效氯氟氰菊酯、溴氰菊酯、甲氨基阿维菌素苯甲酸盐、氯虫苯甲酰胺和溴氰虫酰胺的敏感性较高,LC50值为0.138 1~27.40 mg/L;3龄及4龄幼虫对毒死蜱、高效氯氰菊酯、氟啶脲、茚虫威和虫螨腈敏感性较高,LC50值小于22.63 mg/L,而5龄和6龄幼虫对上述药剂的敏感性均有所降低,LC50值大于38.13 mg/L;各龄期幼虫对甲基嘧啶磷、灭幼脲及新烟碱类杀虫剂的敏感性均较低,LC50值大于40.83 mg/L。双委夜蛾幼虫对不同类别杀虫剂的中毒症状存在差异,其中,经有机磷类、新烟碱类、吡咯类及齅二嗪类杀虫剂处理后,幼虫表现为体表干燥、体壁皱缩;而经拟除虫菊酯类杀虫剂处理后幼虫表现为体壁柔软、充满体液。就生物活性测定结果而言,推荐溴氰虫酰胺、氯虫苯甲酰胺、辛硫磷、联苯菊酯、高效氯氟氰菊酯、溴氰菊酯及甲氨基阿维菌素苯甲酸盐等药剂可用于双委夜蛾的应急防治。  相似文献   

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