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1.
The insecticidal activity of the antiherpetic agent (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) was assessed in in vivo assays against the fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera, Noctuidae). BVDU, mixed into an artificial diet, caused a variety of effects, depending on the concentration used. Compared with controls, food intake was lower, larval growth was retarded and larval development was prolonged. The treated larvae formed smaller pupae and the hatching moths often showed morphogenetic defects. A higher mortality could be found in larval and pupal stages and was generally caused by moult disruption. A choice assay showed that BVDU has very slight feeding-deterrent properties, which only partly explain the toxic effects. The agent most probably acts through its cytostatic activity that has been described previously using cell lines of different insect species. 相似文献
2.
Jeffers LA Shen H Khalil S Bissinger BW Brandt A Gunnoe TB Roe RM 《Pest management science》2012,68(1):49-59
BACKGROUND: Trypsin modulating oostatic factor (TMOF), a decapeptide (Tyr-Asp-Pro-Ala-Pro6) isolated from the ovaries of the adult yellow fever mosquito, Aedes aegypti, regulates trypsin biosynthesis. TMOF per os is insecticidal to larval mosquitoes and a good model for the development of technologies to enhance protein insecticide activity by reduced catabolism and/or enhanced delivery to the target. RESULTS: TFA-TMOF-K (TFA = trifluoro acetyl) allowed the specific conjugation of monodispersed, aliphatic polyethylene glycol (PEG) to the amino group of lysine-producing TMOF-K-methyl(ethyleneglycol)7-O-propionyl (TMOF-K-PEG7P). The addition of lysine to TMOF reduced its per os larval mosquitocidal activity relative to the parent TMOF, but conjugation of TMOF-K with methyl(ethyleneglycol)7-O-propionyl increased its toxicity 5.8- and 10.1-fold above that of TMOF and TMOF-K for Ae. aegypti. Enhanced insecticidal activity was also found for larval Ae. albopictus and for neonates of Heliothis virescens and Heliocoverpa zea. Only TMOF-K was found by MS/MS in the hemolymph for H. virescens fed on TMOF-K-PEG7P. No TMOF, TMOF-K or PEGylated TMOF-K was detected in the hemolymph after topical applications. CONCLUSIONS: This research suggests that aliphatic PEG polymers can be used as a new method for increasing the activity of insecticidal proteins. Copyright © 2011 Society of Chemical Industry 相似文献
3.
BACKGROUND: Although the toxins of Bacillus thuringiensis Berliner (Bt) are frequently used to control lepidopteran pests, the tolerance or resistance of some lepidopteran moth strains may limit Bt applications. In this study, insecticidal cocktails consisting of sublethal doses of Cry1Ab toxin and additive compounds were tested for their suppressive effect on larval relative growth rate (RGR) in Ephestia kuehniella Zeller under laboratory conditions.RESULTS: In the first step, the suppressive effect of diflubenzuron, soybean trypsin inhibitor (STI) and chitinase on RGR was confirmed. In the second step, these compounds were incorporated into a mixture of crushed kernels of Bt maize hybrid MON 810-YieldGard((R)) and its isoline with concentrations of Cry1Ab toxin ranging from 0.011 to 0.091 microg g(-1) diet. An additive effect on the suppression of larval RGR in E. kuehniella was found in a combination of diflubenzuron, STI and STI + chitinase as secondary compounds in insecticidal cocktails. Chitinase showed no additive effect on RGR.CONCLUSION: The highest suppression level was found in cocktails with STI + chitinase as a secondary compound. It is hypothesized that the protease inhibitor (STI) protects both chitinase and Cry1Ab proteins from endogenous proteases in the larval midgut and prolongs their insecticidal activities. The possible application of insecticidal cocktails in the control of E. kuehniella is discussed. Copyright (c) 2008 Society of Chemical Industry. 相似文献
4.
BACKGROUND: The triazole-based antiviral nucleoside ribavirin exhibited significant in vitro insecticidal effects against Spodoptera litura, a finding that has prompted further investigations into its in vivo insecticidal properties and mode of action against this insect pest. RESULTS: Ribavirin showed delayed insecticidal effects on third-instar larvae of S. litura at a concentration of 1 mg mL−1. When incorporated into an artificial diet, ribavirin caused various effects, depending on the concentration used. Compared with controls, food intake was lower, larval growth was reduced and larval development prolonged. Pupae weight was reduced, and adult morphology was also affected. Relative to the untreated group, treated groups showed higher mortality at larval and pupal stages, which was generally caused by moult disruption. Results of this study with ribavirin resemble those found in treatment with insect growth regulators. CONCLUSION: This work shows that ribavirin merits further study as a lead compound in a novel class of potential insect control agents or for managing field populations of Lepidoptera pests on cruciferous crops. Copyright © 2012 Society of Chemical Industry 相似文献
5.
暗黑鳃金龟Holotrichia parallela是一种重要的农业害虫,其成虫和幼虫均能对多种作物造成严重危害。为筛选对暗黑鳃金龟成虫具有毒杀活性的Bt蛋白,本研究首先对暗黑鳃金龟成虫的生活习性进行观察,用浸泡蛋白的榆树叶饲喂成虫,建立了Bt蛋白对暗黑鳃金龟成虫的生物学活性测定方法;制备了6种Bt Cry8类杀虫晶体全长蛋白和胰蛋白酶消化蛋白,对暗黑鳃金龟成虫进行了杀虫活性测定。初筛结果发现Cry8Ga1原毒素和消化蛋白均对暗黑鳃金龟成虫具有较高毒杀活性,其在浓度1.0 mg/mL时对暗黑鳃金龟成虫的7 d校正死亡率分别为100%和55%。为更进一步确定Cry8Ga1蛋白的杀虫活性,进行了致死中浓度测定,7 d生测结果显示,Cry8Ga1原毒素的LC50为0.387 mg/mL （95%置信区间为0.108~0.746 mg/mL）,Cry8Ga1蛋白经胰蛋白酶消化后的LC50为0.702 mg/mL （95%置信区间为0.150~2.664 mg/mL）。取食Cry8Ga1原毒素蛋白及其消化蛋白后的暗黑鳃金龟成虫中肠细胞产生显著的病理学变化。本研究筛选到对暗黑鳃金龟成虫有毒杀作用的Bt蛋白,研究结果将为金龟子的生物防治开辟新的途径。 相似文献
6.
Mustafa M. Ghorab Sami G. Abdel-Hamide Gehad M. Ali El-Sayed H. Shaurub 《Pest management science》1996,48(1):31-35
A series of 14 new 3-[4(3H)-quinazolinone-2-(yl)thiomethyl]-1,2,4-triazoles were prepared and characterized by elemental analyses, IR, [1H] NMR and mass spectral data. Four of the compounds showed insecticidal activity equivalent to that of malathion against the adult stage of the blow fly (Chrysomyia albiceps). However, their activity against the larval stages of this insect species was considerably weaker. 相似文献
7.
Gallo MB Rocha WC da Cunha US Diogo FA da Silva FC Vieira PC Vendramim JD Fernandes JB da Silva MF Batista-Pereira LG 《Pest management science》2006,62(11):1072-1081
The effects of crude extracts, fractions and isolated compounds from Vitex polygama Cham. and Siphoneugena densiflora Berg were evaluated on the development of Spodoptera frugiperda JE Smith, a destructive insect pest of corn and several other crops. The extracts and fractions were incorporated into an artificial diet at 1 mg g(-1) and offered to the insect during its larval stage. Length and viability of larval and pupal stages as well as pupal weight were assessed. Isolated compounds were tested through superficial contamination of the diet at 0.1 mg g(-1). Weight and viability of ten-day-old larvae were determined. Methanolic and hydroalcoholic S. densiflora extracts caused 100% larval mortality, while leaf and fruit hydroalcoholic extracts from V. polygama were the most active. Among the isolated compounds, flavonoids presented the best insecticidal results, and tannins the best larval growth inhibition. 相似文献
8.
应用联杯法等室内测定了0.05%氟虫腈杀蚁饵剂对红火蚁的引诱力、毒杀速度及其传导毒杀活性.结果表明,供试饵剂对红火蚁的引诱性、毒杀速度显著优于正舒(对照药剂).红火蚁觅食到供试饵剂的初始时间为2.00 min,与正舒的2.33 min达显著差异;供试饵剂处理后24 h的工蚁死亡率为80.65%,显著高于对照饵剂的50.15%;72 h的工蚁死亡率即达到100%.联杯法测定结果表明,0.05%氟虫腈杀蚁饵剂能通过工蚁的取食和交哺行为进行传导.供试饵剂受药杯中工蚁、幼蚁和蚁后3 d后死亡率均达到100%,显著高于对照饵剂.0.05%氟虫腈杀蚁饵剂引诱性强、对红火蚁具有高胃毒、高传导毒杀活性,可适用于防控入侵红火蚁. 相似文献
9.
This paper reports the investigation of the insecticidal and fungicidal activity of dunnione, a natural product obtained inadvertently as a by-product of a synthesis programme. Dunnione exhibits no insecticidal activity but has an unusually broad spectrum of antifungal activity. In vitro and in vivo (preventative) activities were comparable to those of several long-established fungicides (eg carbendazim). However, in whole-plant assays, its eradicant activity was unexpectedly low, probably due to poor dose-transfer from leaf surface to fungus. The level of residual activity appears to be influenced by the formulation. Finally, its potential as a lead structure was assessed, and several analogues synthesised which exhibited high activity in the in vitro assays. Mode-of-action studies revealed that dunnione exerts its action primarily through initiation of redox cycling. This contrasts to the activity of BTG 505, the biochemical/chemical precursor, which does not initiate redox cycling but instead exhibits both insecticidal and fungicidal activity by inhibiting mitochondrial Complex III. 相似文献
10.
为了创制高效广谱的绿色杀虫剂,以(E)-4,5-二氢-6-甲基-4-(3-吡啶亚甲基氨基)-1,2,4-三嗪-3(2H)-酮(吡蚜酮)为先导,用带有不同电荷密度的五元、六元取代苯环或杂环取代其结构中的吡啶环部分,合成了10个全新的嘧啶酮类衍生物,特别对其中所包含的三嗪环和二氢喹唑啉酮合成部分进行了重点研究。所有目标化合物的结构均经过核磁共振氢谱、高分辨质谱及红外光谱的确认。初步杀虫活性测试结果表明,目标化合物对蚜虫Aphis craccivora未表现出明显的杀虫活性,初步暗示了先导化合物吡蚜酮结构中所含的吡啶环部分可能对其杀虫活性起了重要作用。 相似文献
11.
BACKGROUND: The cyclodepsipeptide destruxin produced by the entomopathogen Metarhizium anisopliae (Metch.) was administered by different methods, topical application, ingestion and a combination of the two, in an attempt to minimize the mycotoxin dose for efficient management of the insect pest Spodoptera litura (Fab.).RESULTS: The insecticidal activity of destruxin on the larval stages of S. litura showed an ascending trend in LD(50) values with increasing age. The value for 12-day-old larvae in the combined application assay was as low as 0.045 microg g(-1) body weight of crude destruxin from M-19 strain when compared with the corresponding values of 0.17 microg g(-1) body weight in the ingestion assay and 0.237 microg g(-1) body weight in the topical application assay. On the other hand, values were higher in the treatments with crude destruxin from the low-virulence M-10 strain of M. anisopliae showing the least quantities of A and E components of destruxin.CONCLUSION: Laboratory bioevaluation showed the combination assay of ingestion and topical application of crude destruxin to be efficient in enhancing its insecticidal properties. The adopted combination assay apparently simulates application of the insecticide at field level. Quantitative differences between destruxins from low- and high-virulence strains of M. anisopliae are in accordance with its presumed role in virulence. 相似文献
12.
In the course of screening for naturally occurring insecticides from plants from the northwestern part of China, a petroleum ether extract of Juniperus sabina L was found to show insecticidal activity against fifth-instar larvae of Pieris rapae L. From the extract, an insecticidal compound was isolated by bioassay-guided fractionation. The compound was identified as deoxypodophyllotoxin (1) by comparison of its spectroscopic characteristics with literature data. In bioassays, 1 showed antifeedant activity against fifth-instar larvae of P rapae at 0.05-1.00 g litre(-1) and its AFC50 (concentration for 50% antifeedant activity) values at 12 and 48h were 0.170 and 0.060 g litre(-1), respectively. In that concentration range, all treated insects died within 48 h after treatment and compound 1 showed delayed insecticidal activity. At 0.015-0.100 g litre(-1), 1 showed insecticidal activity, with an LC50 of 0.020 g litre(-1). The related compound deoxypicropodophyllotoxin (2), however, showed lower antifeedant and insecticidal activities than 1 in bioassay. This indicated that the trans-lactone ring is an important moiety for enhancing activity in these compounds. Comparison of the insecticidal activities of 1 and another related compound, podophyllotoxin (3), suggested that varying the substituent at C-4 is an exciting possibility for synthesizing more potent analogues. 相似文献
13.
Of six juvenile hormone analogs of the alkyl 3,7,11-trimethyl-2,4-dodecadienate type, only the isopropyl ester was strongly morphogenic in the house fly, Musca domestica L. In vitro assays revealed that house fly microsomes contain B-esterases as well as oxidases which metabolize such analogs. However, these esterases did not hydrolyze the isopropyl ester, ZR-515. Enzymes prepared from larvae, pupae, and adults were all active and there was evidence that in the late larval stage the esterase activity was cyclic, showing a minimum in the early third instar and a maximum a few hours later. When microsomes from two susceptible and two resistant house fly strains were compared for metabolic activity against the juvenile hormone analogs, those from the resistant strains were 1.3 to 20 × higher in oxidase activity but there was no difference in esterase activity. The oxidative metabolism of two analogs ZR-515 and 512 was greatly enhanced when the flies were induced with phenobarbital but there was no enhancement in metabolism of three of the remaining analogs and only a slight enhancement of a fourth. It is concluded that the insecticidal action of ZR-515 is largely due to its stability in the presence of the house fly esterases. 相似文献
14.
Insecticidal activity of chemical constituents from Aristolochia pubescens against Anticarsia gemmatalis larvae 总被引：1，自引：0，他引：1
Acetone and ethanol extracts of the tubercula and several compounds isolated from Aristolochia pubescens (Willd) were bioassayed on velvetbean caterpillars, Anticarsia gemmatalis (Hübner), for evaluation of the insecticidal activities. Of the extracts subjected to bioassay, the acetone extract showed the highest activity. (-)-Cubebin did not show activity against soybean caterpillars, whereas aristolochic acid and ent-kaur-15-en-17-ol increased the larval period. These compounds, and (+)-eudesmin and (+)-sesamin, reduced the viability of this period, giving rise to malformed adults. These extracts and compounds are therefore potential botanical insecticide agents for the control of velvetbean caterpillars in soybean crops. 相似文献
15.
N3-substituted imidacloprid congeners containing C1-C6 alkyl groups or various analogous groups, and their corresponding nitromethylene analogues, were used in this study. Their insecticidal activity against the housefly, Musca domestica, and their binding activity toward the nicotinic acetylcholine receptor were determined. The insecticidal test was conducted using the synergists piperonyl butoxide and propargyl propyl phenylphosphonate. The binding assay was performed with housefly head membrane preparations using radio-labelled alpha-bungarotoxin. Both insecticidal and binding activities were drastically lowered by the introduction of alkyl/allyl groups at the imidazolidine NH sites of both nitroimino and nitromethylene compounds. The binding activity of N3-substituted nitromethylene analogues was much higher than that of the corresponding nitroimino analogues. However, the insecticidal activity of both series of compounds with a given substituent was nearly identical. The insecticidal activity correlated positively with the binding activity after taking into account the structural difference of the nitroimino and nitromethylene moieties and a structural feature of the N3-substituents. 相似文献
16.
Dos Santos Monteiro AC de Oliveira Neto OB Del Sarto RP de Magalhães MT Lima JN Lacerda AF Oliveira RS Scharfstein J da Silva MC Valencia JW Jiménez AV Grossi-de-Sa MF 《Pest management science》2008,64(7):755-760
BACKGROUND: The activity of the major digestive cysteine proteinase detected in the intestinal tract of larvae of the bean weevil, Acanthoscelides obtectus (Say), was efficiently inhibited by the well-characterized cysteine proteinase synthetic inhibitor E-64 and also by a recombinant form of chagasin (r-chagasin), a tight-binding cysteine proteinase inhibitor protein from Trypanosoma cruzi. RESULTS: Incorporation of r-chagasin into an artificial diet system at 0.1 g kg(-1) retarded growth rate, decreased larval survival and led to complete mortality of A. obtectus at the end of the trial. The observed differences in growth rates occurred particularly in the first and second development stages. Artificial seeds containing high levels of r-chagasin (0.5-30 g kg(-1)) completely inhibited larval penetration. CONCLUSION: Together, the results reported in this paper support the hypothesis that the inhibitory activity of r-chagasin towards the major insect gut cysteine proteinase in vitro and in vivo is an accurate prediction of its insecticidal effects. The selectivity of this inhibitor against insect digestive proteinases supports the key role in parasite virulence by affecting the endogenous proteinase activity in its natural host. 相似文献
17.
J Cristian Vidal‐Quist Pedro Castañera Joel González‐Cabrera 《Pest management science》2010,66(9):949-955
BACKGROUND: Ceratitis capitata (Wiedemann) is one of the world's most destructive fruit pests. The aim of this study was to ascertain insecticidal activity of Bacillus thuringiensis (Berliner) δ‐endotoxins to C. capitata. RESULTS: Among 42 selected Bacillus strains, only B. thuringiensis serovar israelensis (Bti) solubilised protoxins showed biological activity against C. capitata neonate larvae, whereas Bti spore and crystal mixture was inactive. Insecticidal activity of Bti protoxins was significantly enhanced by incubation with Culex pipiens L. gut extracts. Overdigestion of Bti protoxins with Sesamia nonagrioides (Lefebvre) gut extracts suppressed biological activity against C. capitata, and this correlated with degradation of Cyt toxins. Cyt1Aa solubilised protoxin showed the highest toxicity, LC50 after 7 days of 4.93 µg cm?2, while proteolytical processing of Cyt1Aa protoxins by larval gut extracts did not enhance insecticidal activity. CONCLUSION: The present study provides evidence for the first time of the insecticidal activity of a B. thuringiensis strain against C. capitata and identifies a single δ‐endotoxin with potential for controlling this pest. Copyright © 2010 Society of Chemical Industry 相似文献
18.
苦参杀虫抑菌活性成分研究 总被引：15，自引：0，他引：15
苦参(SophoraflavescensAit)为豆科槐属灌木,分布广泛,是我国历史悠久的传统药物之一,主要功效清热、杀虫、利尿、祛湿[1]。苦参在农业上的应用,近几年引起人们的重视,有1.1%苦参碱醇溶液等几个产品获得登记。但多数研究只是停留在苦参的粗提物直接用于病虫害防治上,对苦参的生物活性与其成分的联系研究甚少。本文以生物活性追踪试验为指导,从苦参提取物中分离到2个主要杀虫抑菌活性化合物,参考文献报道的波谱数据,确定其结构分别为苦参酮(Kurarinone)(I)和槐属二氢黄酮G(SophoraflavanoneG)(II)。I R=OCH3 II R=H1 结果与讨… 相似文献
19.
筛选对草地贪夜蛾高毒力Bt菌株,对于开发绿色高效防治草地贪夜蛾新产品具有重要意义。本研究从自行筛选的对夜蛾科害虫高毒力的Bt菌株资源中,选取9株菌株进行草地贪夜蛾室内毒力测定,并对高毒力菌株进行杀虫基因分析;选取室内毒力测定活性最高的3株菌株进行田间小区药效试验。结果表明,9株Bt菌株在药后7 d对草地贪夜蛾初孵幼虫均表现出显著的毒杀效果,LC50范围在0.07~3.38μg/g,其中毒力最高的3个菌株分别是KN50、KN11和KNR8,LC50分别为0.07、0.23和0.43μg/g,表现非常显著的致死效果;对KN50、KN11和KNR8等6种高毒力的Bt菌株的杀虫基因分析发现,他们都含有vip3Aa、cry2Ab、cry1Ac、cry1Ia杀虫基因。KN50、KN11和KNR8菌株的32000IU/mg制剂在田间对草地贪夜蛾表现出不同程度防效,其防效高低与室内毒力结果一致,其中KN50药后7 d防效最高,在200和400 g/667 m2下对1~3龄幼虫防效分别可达86.09%和95.22%,对不同龄期幼虫混发的防效为72.61%和86.59%。因此KN50、KN11和KNR8这3个菌株能作为备选高效菌株用于防治草地贪夜蛾新产品开发,为实现草地贪夜蛾的绿色防控、化学农药合理减替提供重要保障。 相似文献
20.
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