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1.
为明确二化螟幼虫群集密度对种群增长的影响,在室内用人工饲料饲养比较了不同幼虫密度对二化螟生长发育的影响。结果表明,高幼虫密度800头/盒胁迫下,二化螟雌、雄幼虫和蛹的发育更快,其幼虫+蛹历期分别比低密度100头/盒处理要快8.0 d和6.0 d;化蛹率和羽化率较100头/盒处理分别显著下降了25.7和25.0个百分点,且雌、雄蛹重分别减少了9.4 mg和4.8 mg;但对二化螟成虫性比、寿命、产卵量和卵孵化率无显著影响。低密度100头/盒处理下二化螟幼虫发育最好,其种群增长指数为56.9,化蛹率达61.4%,羽化率达57.7%,雌、雄蛹重分别为58.3 mg和43.0 mg,但其幼虫+蛹历期较长,雌虫为58.5 d,雄虫为53.9 d。高密度800头/盒胁迫下二化螟幼虫发育最差,其种群增长指数仅为24.1,化蛹率仅为35.7%,羽化率为32.7%,雌、雄蛹重分别为48.9 mg和38.2 mg,但其幼虫+蛹历期较短,雌虫为50.5 d,雄虫为47.9 d。表明在恒定的空间和有限的食物中,幼虫密度过大会导致种内竞争加剧,使得幼虫可能倾向以更快的速度化蛹,确保其存活率以更好地繁殖后代。 相似文献
2.
The activity of rhodojaponin-III (R-III), a grayanoid diterpene compound isolated from Rhododendron molle G. Don flowers, was determined under laboratory and field conditions as an antifeedant, stomach poison, contact toxicant and insect growth inhibitor against Pieris rapae (L.) larvae. The median antifeedant concentration (AFC(50)) values in no-choice leaf disc tests were 1.16 and 15.85 mg L(-1) at 24 h after treatment when tested against third and fifth instars respectively. The median lethal concentration (LC(50)) values in leaf disc tests were 2.84 and 9.53 mg L(-1) at 96 h after treatment against third and fifth instars respectively. R-III showed an almost 30 times higher contact toxicity against third instars than for fifth instars, and the median lethal dose (LD(50)) values for topical application were 1.18 and 34.09 mg kg(-1) at 72 h after treatment respectively. R-III disrupted the development of larvae to pupae or adults with median concentration for inhibiting growth (IC(50)) values of only 1.36 mg L(-1) for third instars and 11.28 mg L(-1) for fifth instars. In field trials, a greater than 80% reduction in the adjusted larval numbers was obtained against P. rapae 14 days after treatment when Rhodo 0.1% EC, a commercial botanical insecticide based on R-III, was applied at both 937.5 and 625 mL ha(-1). These results suggest that further research to develop R-III, and extracts from R. molle, as biorational pesticides or as lead compounds for integrated pest management deserve consideration. 相似文献
3.
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
4.
Three rearranged phragmalin-type limonoids, khayanolide A, khayanolide B and 1-O-acetylkhayanolide B, and a mexicanolide-type limonoid, khayalactol, have been isolated from the stem bark of Khaya senegalensis (Desr) A Juss (Meliaceae). The antifeedant and growth-inhibitory activities of the isolated compounds were evaluated on Spodoptera littoralis (Boisduval). When added to an artificial diet, khayanolide A, khayanolide B and 1-O-acetylkhayanolide B showed antifeedant activity in a concentration-dependent manner. Khayalactol exhibited strong antifeedant activity without significant differences at all of the tested concentrations (7.5-100 mg kg(-1)). Khayanolide B was the most potent antifeedant with an ECso of 2.19 mg kg(-1). The results also revealed that the isolated compounds caused marked larval growth inhibition on S littoralis after 7 days of feeding on treated diet; this effect was concentration-dependent. Khayanolide B was the most active growth inhibitor among the isolated compounds, with an EC50 of 6.96 mg kg(-1). 相似文献
5.
Sampson BJ Tabanca N Kirimer N Demirci B Baser KH Khan IA Spiers JM Wedge DE 《Pest management science》2005,61(11):1122-1128
Essential oils from 23 species of plants comprising 14 genera and 4 plant families were obtained by Clevenger-type water distillation. The major compounds in these essential oils were identified with GC-MS and their insecticidal activity against adult turnip aphids, Lipaphis pseudobrassicae (Davis), tested with dosage-mortality bioassays. We examined mortality only for viviparous adults because sizeable aphid populations on crucifer (Brassicaceae) hosts are largely produced by these wingless, parthenogenic females. Twenty-two of the oils were directly applied to aphid females in randomized blocks at concentrations of 0.0, 1.0, 2.5, 5.0 and 10.0 mg ml(-1). Essential oils mixed with a non-toxic emulsifying agent, dimethyl sulfoxide (DMSO), more easily penetrated the waxy insect cuticle. Probit analysis and LC(50) at three different exposures showed aphids were quickly incapacitated and killed by aliphatic aldehydes, phenols and monocyclic terpenes contained in Bifora and Satureja oils and at applied concentrations as low as 0.3 to 1.0 mg ml(-1). Only enough Pimpinella isaurica oil and its three phenylpropanoid fractions were available for testing at a single concentration of 10 mg ml(-1). We could not spare any additional P. isaurica oil for testing at other concentrations. Phenylpropanoids isolated from P. isaurica oil when recombined or left naturally blended in the oil were highly bioactive against L. pseudobrassicae at 10 mg ml(-1). 相似文献
6.
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
7.
Aupinel P Fortini D Michaud B Marolleau F Tasei JN Odoux JF 《Pest management science》2007,63(11):1090-1094
A new in vitro method was devised to assess the effects of pesticides on honey bee brood. The method allowed the quantification of doses ingested by larvae and the assessment of larval and pupal mortality. Larval mortality in control samples was lower than 10%. Two active substances were tested: dimethoate and fenoxycarb. The LD(50) of dimethoate was 1.9 microg larva(-1) 48 h after oral exposure of larvae at day 4. Additional dose-related effects on pupal mortality were noted. After a chronic intoxication, the NOAEC (No Observed Adverse Effect Concentration) for larval mortality at day 7 was 2.5 mg kg(-1), whereas a NOAEC of 5 mg kg(-1) was found at day 22 for delayed effects on the reduction of adult emergence. Fenoxycarb applied at day 4 showed no effect on larvae, whereas emergence of adults was affected at doses higher than 6 ng larva(-1). 相似文献
8.
雷公藤非生物碱成分对菜青虫杀虫活性研究 总被引：16，自引：0，他引：16
雷公藤 ( Tripterygiun wilfordii Hook)属卫矛科雷公藤属植物 ,又名断肠草、菜虫药 ,在我国主要分布于长江中下游地区 ,为著名的杀虫植物之一 [1～ 3]。据资料报道 ,雷公藤主要有效杀虫成分为生物碱类 ,现已分离出 5种有杀虫活性的生物碱 [3]。 Beroza等 [2 ]还发现 ,分离出 5种生物碱后剩下的非结晶物质对欧洲玉米螟 ( Pyrausta nubilalis)初孵幼虫及蚊虫杀虫活性很好。雷公藤非生物碱成分和生物碱的中毒症状相似 ,但有关非生物碱的杀虫作用方式目前还未见报道。作者采用生物活性追踪与化学分离技术相结合的方法 ,从雷公藤根皮中得到了… 相似文献
9.
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
10.
Laboratory evaluation of the insect growth regulator lufenuron againstHelicoverpa armigera on cotton
An insect growth regulator (IGR), lufenuron (Match 5EC), was tested for its toxicity toHelicoverpa armigera on cotton. Potency of the IGR against the larval stage of the pest was demonstrated with respect to larval instars; the LC90 values of 1st, 2nd, 3rd, 4th and 5th instar larvae were 5.63, 7.89, 8.03, 11.39 and 14.76 mg a.i.l
−1, respectively. However, different larval instars did not differ significantly with respect to LC50 and LC10. IGR-treated larvae had swollen heads and were significantly smaller (1.5–2.3 mm) than the untreated control (2.9 mm). Larval
weight was significantly reduced from 190 mg in the control to 50–70 mg in the lufenuron treatment. IGR treatment in the larval
stage significantly affected both pupal length and pupal weight. Pupal duration of the test insect was significantly extended
by IGR treatment. Pupal deformities, including an inability to shed the last larval skin and formation of larval-pupal intermediates,
occurred following treatment. A significant reduction in adult emergence was recorded. In addition, abnormalities in the form
of development of cavities in the forewings of adult were evident. A significant decline in fecundity was noted in the studies.
http://www.phytoparasitica.org posting Feb. 3, 2003. 相似文献
11.
为明确无患子皂苷对甜菜夜蛾的控制作用,本试验分别用添加无患子皂苷(0.25、0.5、1、2、4、8、16 mg/g)的混毒饲料喂养甜菜夜蛾2龄幼虫,测定甜菜夜蛾幼虫存活率、幼虫发育历期、蛹重、化蛹率、卵孵化率、性比等指标。采用液相色谱-质谱联用仪(HPLC-MS)分析无患子皂苷中的主要化学成分。结果表明,喂饲后72 h,取食4 mg/g混皂苷饲料的甜菜夜蛾幼虫开始死亡,其幼虫存活率随皂苷浓度的升高而降低;相比空白对照组,取食4 mg/g混皂苷饲料的幼虫,其幼虫期延长8.55 d(P<0.05),蛹重降低了41.13%(P<0.05),化蛹率下降46.43%(P<0.05)。取食0.5 mg/g以及2 mg/g混皂苷饲料的幼虫其卵孵化率分别比空白对照降低9.61%、16.12%;取食混有皂苷的饲料会扰乱甜菜夜蛾的性比,其中混入2 mg/g皂苷的处理对其性比影响最大,雌性比为25.00%。从无患子皂苷中鉴定出10种皂苷类化合物,共鉴别出6种常春藤型三萜皂苷,3种齐墩果酸型三萜皂苷,1种大戟烷型三萜皂苷。 相似文献
12.
In Mauritius, the sterile insect technique (SIT) is being developed to manage the Peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae). Novel and economical larval diets are needed to produce millions of artificially reared sterile flies needed to ensure the success of this programme. We assessed the efficacy of conventional (solid) and gel diets with formulations containing modified waste brewery yeast (WBY), an alternative low cost protein source. The WBY is obtained freely from the manufacturing plant located at the Entomology Division of the Ministry of Agro Industry & Food Security, Réduit, Mauritius. Its chemical composition is highly comparable to those of the imported commercial yeast. Formulations of both diet types varied in the ratio of WBY (%) to commercial yeast (CY) (%) (Control: 0:100, A: 25:75, B: 30:70; C: 40:60; D: 50:50). The quality parameters of flies reared on the modified gel larval diets i.e. volume of pupae, pupal weight, pupal recovery, percentage adult emergence and percentage fliers were comparatively better on the gel diet formulations B, C and D, while no significant difference in percentage egg hatch was observed between the conventional diet and the gel diet. The optimum egg seeding rate (larval density) for selected gel diets B, C and D was determined. Formulation C using 0.15 ml of eggs/100 g of diet resulted in the highest pupal recovery, pupal weight, emergence and flight ability. A five-year cost benefit analysis revealed a net cost saving of 38% (US$ 53 418.20) by using the gel diet with WBY instead of the solid diet. The cost for the production for one million flies is US$ 310.67. Our results demonstrate that the selected gel diet formulation in which commercial yeast is partially replaced by waste brewery yeast is a viable alternative to the conventional solid diet for rearing of B. zonata. There are also the added benefits in terms of reduced cost with respect to storage and disposal, due to the elimination of bulking agents.
相似文献13.
α-Terthienyl, a common chemical constituent in the Asteraceae, was administered to fifth-stadium larvae (Day 1) of the tobacco hornworm, Manduca sexta (L.) (Sphingidae), by incorporation into artificial diet and by topical application. Toxicity toward larvae was elicite by simultaneous exposure to this allelochemical and uv-A irradiation (320–400 nm). Larval treatment with either α-terthienyl or uv-A irradiation alone caused no apparent adverse effects. A single, ingested dose of α-terthienyl (50 μg g larval weight?1), followed by irradiation for 4 hr, resulted in delayed and abnormal pupal formation with no subsequent adult emergence. Topical application of the plant compound (50 μg g?1) and uv-A irradiation led to tissue necrosis that affected both sclerotization and melanization of the pupal case in later development. 相似文献
14.
Feeding stimulants (phagostimulants) increase the food uptake by the host insect larvae and thereby play a vital role in enhancing overall activity of insect viruses formulated as biopesticides. A local strain of granulovirus of Pieris brassicae (PbGV), a serious pest of cole crops worldwide, has shown potential as a biopesticide against this pest and with slight increase in its efficacy can be used successfully as a promising biocontrol agent in integrated pest management (IPM) programs of the pest. The addition of phagostimulants may enhance the efficacy but so far no specific phagostimulant for PbGV has been reported. In the present studies, some reported phagostimulants for insect viruses were tested for their impact on food utilization by host larvae and efficacy of the virus. The specified concentration of virus isolate was mixed with phagostimulants and laboratory studies were conducted to uncover their effect on consumption index (CI) and larval mortality. The studies revealed that phagostimulants, viz. boric acid and crude sugar, when mixed with PbGV, showed highest CI and larval mortality. Consumption index of 1.34, 1.49 and 1.43 mg/mg/day and corresponding larval mortality of 32.9%, 45.8% and 34.2% were recorded with the addition of 0.5% and 1% boric acid and 2% crude sugar, respectively, in PbGV. The leaf extracts of cabbage, cauliflower and broccoli at both the concentrations (1% and 2%) also enhanced the CI but were comparatively less effective than the boric acid and crude sugar. Field evaluation of PbGV alone and in combination with phagostimulants carried out at two geographically isolated locations, viz. Palampur (subtropical) and Sangla (temperate) on three cole crops (cabbage, cauliflower and broccoli) showed that boric acid was the most promising candidate for enhancing the PbGV efficacy under field conditions, followed by crude sugar. 相似文献
15.
Bigi MF Torkomian VL de Groote ST Hebling MJ Bueno OC Pagnocca FC Fernandes JB Vieira PC da Silva MF 《Pest management science》2004,60(9):933-938
The focus of this study was the identification of compounds from plant extracts for use in crop protection. This paper reports on the toxic activity of fractions of leaf extracts of Ricinus communis L (Euphorbiaceae) and isolated active compounds in the leaf-cutting ant Atta sexdens rubropilosa Forel and its symbiotic fungus Leucoagaricus gongylophorus (Singer) M?ller. The main compounds responsible for activity against the fungus and ant in leaf extracts of R communis were found to be fatty acids for the former and ricinine for the ants. 相似文献
16.
BACKGROUND: Biopesticides based on Beauveria bassiana (Bals.) Vuillemin hold great promise for the management of a wide range of insect pests. The conidia in the biopesticide formulation require an adjuvant to protect them from photoinactivation by sunlight. The suitability of Tinopal, an optical brightener used as sunscreen for baculovirus formulations, for use with B. bassiana was assessed. The aim was to study the effect of Tinopal on the growth and photoprotection of B. bassiana, and its effect on the susceptibility of insects to B. bassiana. RESULTS: Tinopal was found to have no adverse effect on the growth of B. bassiana. It was found to confer total protection (approximately 95% conidial germination at 10 g Tinopal L(-1)) from sunlight up to 3 h of exposure, and a better survival rate than controls even up to 4 h. Helicoverpa armigera Hübner larvae fed on diet with 5 g kg(-1) Tinopal were found to have reduced growth. The duration of the larval stage increased by 3-4 days in 1 and 5 g kg(-1) Tinopal treatments. Among the moths that emerged from larvae fed on diet with 5 g kg(-1) Tinopal, a significantly high number were malformed compared with controls. The larvae that were fed diet with Tinopal showed quicker and higher mortality and required a lower effective lethal dose (LC(50)) than the controls. Tinopal was found to have a synergistic effect with B. bassiana in causing insect mortality. CONCLUSIONS: Tinopal was found to be a suitable adjuvant for B. bassiana-based biopesticide formulations. It conferred tolerance to sunlight and caused stress in the insect, leading to a synergistic effect with B. bassiana. 相似文献
17.
Potato leaves were treated with 2, 20 or 200 g kg(-1) solutions of extracts of five plant species collected in Turkey, and then exposed to larvae of Colorado potato beetle, Leptinotarsa decemlineata (Say). During the first 24 h of exposure, leaf consumption was not affected by 2 g kg(-1) extracts, whereas significantly more leaf tissue remained on leaves treated with 20 g kg(-1) extracts of Arctium lappa L., Bifora radians M Bieb, Humulus lupulus L. or Xanthium strumarium L. than on untreated control leaves. Feeding was not affected by the 20 g kg(-1) extract of Verbascum songaricum Schrenk ex Fisch & Mey. Extracts of all species at 200 g kg(-1) reduced larval feeding, with H. lupulus and X. strumarium providing the greatest protection. Observations of larval behaviour over the first 15 min of exposure to these extracts revealed that the interaction of beetles with leaf tissue was significantly affected by plant extracts. Feeding frequency was not affected by 2 g kg(-1) extracts but was reduced by all higher concentrations. Feeding was inhibited completely by 20 g kg(-1) of H. lupulus extract and reduced significantly compared with the controls by all other extracts. Suppression of feeding was caused by all extracts at 200 g kg(-1), with V. songaricum providing 91% reduction in feeding duration. Rejection behaviour, in which larvae did not return to the leaf after their interaction with it, was rare on 2 g kg(-1) extracts but seen in over 60% of larvae on 20 g kg(-1) extracts and over 80% on 200 g kg(-1) extracts. The present results demonstrate that these extracts have significant ability to protect potato leaves for up to 24 h by prevention of feeding behaviour by L. decemlineata. Further studies are needed to determine the potential of these plant extracts, or their active components, for use in biologically based pest management strategies. 相似文献
18.
为了探讨寄生不同寄主对花绒寄甲Dastarcus helophoroides（Fairmaire）生长发育和耐寒性的影响，于室内分别用鞘翅目的Zophobas morio蛹、麻竖毛天牛Thyestilla gebleri和松褐天牛Monochamus alternatus Hope的幼虫作为寄主，统计和分析花绒寄甲的发育历期、成虫产出数、成虫个体大小和过冷却点。结果发现：寄生不同寄主对花绒寄甲的成虫产出数无显著影响，但对其幼虫历期、蛹历期、成虫体长、成虫体重和过冷却点有显著影响。寄生Zophobas morio蛹的花绒寄甲幼虫历期（10.58 d）和蛹历期（30.17 d）均最长，成虫体长最长（8.68 mm），体重最重（360.22 mg），过冷却点最低（-18.81℃）；而寄生麻竖毛天牛幼虫的花绒寄甲幼虫历期（8.94 d）和蛹历期（22.84 d）均最短，成虫体长最短（6.33 mm），体重最轻（184.38 mg），过冷却点最高（-16.50℃）。相比麻竖毛天牛和松褐天牛的幼虫，Zophobas morio蛹所繁育的花绒寄甲成虫体型更大且耐寒性更强，Zophobas morio蛹是繁育更为健壮和耐寒的花绒寄甲种群的理想替代寄主。 相似文献
19.
近年来斜纹夜蛾已发展为影响大豆生产的世界性虫害。对大豆抗斜纹夜蛾种质资源进行鉴定是开展抗虫育种的基础。野生大豆是栽培大豆祖先种,遗传多样性远远超过栽培大豆,从野生种质中发掘斜纹夜蛾抗性资源可以拓宽抗虫育种遗传基础。采用室内喂养斜纹夜蛾幼虫的方法,以幼虫重和蛹重为指标,鉴定了35份野生大豆和20份栽培大豆对斜纹夜蛾的抗性。结果显示:不同种质饲喂下,幼虫重、蛹重和幼虫历期在种质间差异极显著,遗传变异幅度较大,幼虫重和蛹重极显著相关。采用标准品种分级法对抗性鉴定结果进行划分,从55份供试资源中筛选出6份高抗种质,均来自野生大豆;5份高感材料,1份来自野生大豆。本研究为大豆抗斜纹夜蛾育种提供了原始材料,同时有助于大豆抗虫遗传研究与新基因发现。 相似文献
20.
甜菜夜蛾生殖能力与蛹重、饲料之间的关系 总被引：6，自引：1，他引：5
以大豆、小麦、酵母粉为主要原料配成的人工饲料饲养甜菜夜蛾,平均单头蛹重为97.97±1.76mg,范围为48～141mg;天然饲料饲养的为88.15±2.49mg,范围为34～133mg。将蛹重分为单头130mg以上、120～129、110～119、100～109、90～99、80～89和80mg以下等7个级别。人工饲料的主要分布在90～110mg之间,占48.44％;天然饲料的主要分布在80～100mg之间,占51.62％。各雌蛹重量级别(人工饲料,第3代)怀卵量分别为:1050±358、876±280、876±192、971±110、921±117、764±156和613±133粒,天然饲料的为496±179粒。结果表明,卵量与雌蛹重基本呈正相关,其生殖能力最强的雌蛹重在80～110mg之间。 相似文献