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1.
斜纹夜蛾的生物控制研究   总被引：10，自引：0，他引：10  
应用以作用因子组配的生命表技术及其相应的分析方法,开展了几项生物防治措施单项和联合使用防治斜纹夜蛾(Spodoptera litura Fabricius.)的试验。结果表明,施用斜纹夜蛾核型多角体病毒(Spodoptera litura nuclear polyhedrosis virus)(浓度为3.1×10~7PIBs/ml,即每g虫尸兑水800倍液)和散放叉角厉蝽(Cantheconidea furcellata Wolff)(1.8头/m~2)均能控制斜纹夜蛾种群的增长。采用两项生防措施后,种群趋势指数值分别降至对照的0.0259倍和0.0532倍,当联合使用这两项生防措施后,种群趋势指数值则降至对照的0.0109倍。浇施斯氏线虫需高剂量(40～80万条/m~2)才能控制斜纹夜蛾种群数量的增长,高剂量可使种群趋势指数值下降至对照的0.758～0.094倍。若以短期内对害虫的杀伤作用作为评价依据,散放叉角厉蝽(1.8头若虫/m~2)的效果最好,进入暴食期的虫口密度下降到对照的0.0917倍.  相似文献   

2.
新型杀虫剂甲磺虫腙的合成与杀虫活性   总被引：1，自引：0，他引：1  
以对氯苯甲酰氯、苯甲醚、甲基磺酰氯、水合肼、丁酮等为原料合成了新型杀虫剂甲磺虫腙(试验号:ZJ0967),其化学名称为甲磺酸-4- 苯酯,其结构经1H NMR、MS和元素分析确认。室内生测结果表明,甲磺虫腙对小菜蛾Plutella xylostella、甜菜夜蛾Spodoptera exigua,特别是对粘虫Mythimna sepatara、斜纹夜蛾Prodenia litura表现出良好的杀虫活性。进一步毒力测定表明,甲磺虫腙对斜纹夜蛾的LC50值为8.45(7.69~9.62) mg/L,其杀虫活性与虫酰肼相当,但低于氟啶脲。田间试验结果表明,70%甲磺虫腙WG在有效成分为210~420 g/hm2时,对斜纹夜蛾7 d的防效可达88.6% ~93.9%,未观察到对作物产生药害。  相似文献   

3.
Analysis on polyacrylamide gels of the soluble protein fraction of cucumber cotyledons infected with tomato spotted wilt virus (TSWV) revealed a stimulated protein component, designated as protein E1. The amount of protein E1 was related to the size and number of local lesions produced on the inoculated cotyledons. Protein E1 stained positive for carbohydrate and could be partly purified by gel filtration on Sephadex G 100. The molecular weight was estimated to be approximately 22000 d. Protein E1 seems to be serologically unrelated to any of the structural proteins of TSWV. Following inoculation of cucumber cotyledons with the yellow strain of cucumber mosaic virus (CMV), a protein with identical mobility on 7.5 and 10% polycrylamide gels to protein E1 was detected. These proteins are probably identical and their accumulation is a result of the infection process. There was a close correspondence between the amount of protein E1 and the severity of symptom expression. A protein with a mobility differing slightly from protein E1 occurred in the soluble protein fraction ofNicotiana rustica after infection with either TSWV or tobacco mosaic virus.  相似文献   

4.
从花椒凤蝶(Papilio xuthus Linnaeus)幼虫中分离到一株核型多角体病毒,其多角体平面图象为四、五边形或近圆形,直径1.6—4.0微米,病毒粒子杆状,微弯,两端圆滑,约360×45毫微米。室内和野外在自然条件下试验结果表明,此株病毒对花椒凤蝶幼虫有较强的致病力,对三龄幼虫的LC_(50)为1.4×10~(4.2)多角体/毫升,y=2.48+0.61x。野外防治效果可达85％以上,好于常用化学农药乐果和马拉硫磷。此株病毒对家蚕、柞蚕和瓢虫无致病作用。  相似文献   

5.
An extracellular chitinase was purified from Bacillus subtilis. The lethal concentration (LC50) was determined by using chitinase in first, second, and third instars of Spodoptera litura Fab. Chitinase showed the highest insecticidal activity at 6 μM concentration within 48 h. The nutritional indices were also significantly affected by the 6 μM concentration (P < 0.05). Food consumption, efficiency of conversion of ingested and digested food, relative growth rate, and consumption values declined significantly while approximate digestibility was increased. Our study indicates that treatment of host plant leaves with the chitinase can regulate (reduce) larval growth and weight, and enhance the mortality. This may serve as an effective biocide and alternative to Bt toxin.  相似文献   

6.
The infectivity of three viruses in leaf material dried over CaCl2 and stored under different conditions was tested over a period of seven years. Alfalfa mosaic virus and cucumber mosaic virus kept very well for the entire period both at 4°C and at room temperature, provided they were stored over CaCl2 in well-closed tubes. The infectivity of bean yellow mosaic virus, however, gradually declined, especially at room temperature. In open or loosely closed containers without CaCl2 none of the viruses survived more than three months of storage and the infectivity of bean yellow mosaic virus declined after only two weeks.  相似文献   

7.
The present work deals with the insecticidal efficacy of different modified natural silica products against the field pests Epilachna vigintioctopunctata (F.) and Spodoptera litura (F.). The substances “Fossil Shield® 90.0s”, “Advasan®” as well as different formulations of a silica-derived substance named “AL06” (developed in the section Urban Horticulture, Humboldt-University Berlin) were dusted into gauze-covered cages. In each cage, test insects were placed and mortality measured over time. A 100% mortality rate was archieved two days after treatment of adult E. vigintioctopunctata and S. litura larvae with some silica “AL06”-formulations. In contrast, mortality rate for E. vigintioctopunctata larva was only 30 to 70% after two days of treatment. Mortality rate was dose dependend, even though a linear correlation could not be found. Furthermore, the commercial substance “Advasan®” was able to control the horticultural pest E. vigintioctopunctata within 48 hours successfully. For future horticultural applications, possible phytotoxic side effects of silica dusts and an application technology resulting in adequate leaf coverage have to be considered.  相似文献   

8.
Laboratory tests showed that a 2% neem (Azadirachta indica A. Juss) seed kernel suspension (NSKS) in water sprayed onSpodoptera litura (F.) eggs before or after parasitization did not adversely affect the emergence of the egg parasiteTelenomus remus Nixon. When sprayed on eggs before parasitization, the treatment did not repel the parasite. The treatment accelerated the development of the parasite but significantly reduced the longevity of its adult. When parasitized eggs were treated, NSKS significantly increased the adult parasite longevity. Thus, a schedule of NSKS sprays can be integrated withT. remus for the control of the tobacco caterpillar,S. litura, in tobacco nurseries.  相似文献   

9.
Seasonal occurrence of the common cutworm Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) moths captured in synthetic sex pheromone traps and associated field population of eggs and larvae in soybean were examined in India from 2009 to 2011. Male moths of S. litura first appeared in late July or early August and continued through October. Peak male trap catches occurred during the second fortnight of September, which was within soybean reproductive stages. Similarly, the first appearance of S. litura egg masses and larval populations were observed after the first appearance of male moths in early to mid-August, and were present in the growing season up to late September to mid-October. The peak appearance of egg masses and larval populations always corresponded with the peak activity of male moths recorded during mid-September in all years. Correlation studies showed that weekly mean trap catches were linearly and positively correlated with egg masses and larval populations during the entire growing season of soybean. Seasonal means of male moth catches in pheromone traps during the 2010 and 2011 seasons were significantly lower than the catches during the 2009 season. However, seasonal means of the egg masses and larval populations were not significantly different between years. Pheromone traps may be useful indicators of the onset of numbers of S. litura eggs and larvae in soybean fields.  相似文献   

10.
Some aspects of the metabolism of a new insecticide, 1,1-bis-(p-ethoxyphenyl)-2-nitropropane have been investigated in the house fly, Musca domestica and the cluster caterpillar, Spodoptera litura. In the house fly the compound was deethylated and after 24 hr exposure, 1-(p-ethoxyphenyl)-1-(p-hydroxyphenyl)-2-nitropropane and 1,1-bis-(p-hydroxyphenyl)-2-nitropropane were isolated. From evidence given below it is probable that conjugates of these compounds were also present. Feeding of the insecticide to S. litura resulted in the excretion of mainly unchanged insecticide although a small percentage was converted to a polar compound tentatively identified as 1,1-bis-(p-hydroxyphenyl)-2-propanone.  相似文献   

11.
A total of 27 entomopathogenic nematode (EPN) strains originally isolated from different cotton fields were characterized in laboratory experiments for their virulence, reproductive potential and environmental tolerance. The EPN strain collections included 16 Steinernema carpocapsae (SC), three Steinernema siamkayai (SS), one Steinernema monticolum (SM), and seven Heterorhabditis bacteriophora (HB). Their virulence was tested against cotton bollworms such as the American bollworm Helicoverpa armigera, the spotted bollworm Earias vittella and the cotton leafworm Spodoptera litura. Larvae of H. armigera, E. vittella and S. litura were susceptible to all the tested EPN species/strains with significant differences among EPN species/strains. The most virulent strains were APKS2 (SC), TRYH1 (HB) KKMH1 (HB) and KKMH2 (HB) on H. armigera (91.9–93.5% mortality); KKMS1 (SC), APKS2 (SC), TRYH1 (HB), KKMH1 (HB), KKMH2 (HB) and APKH1 (HB) on E. vittella (92.7% mortality); and APKS2, TRYH1, KKMH1, KKMH2 and KKMH3 on S. litura (92.7% mortality). The results of the invasion rate assay indicated that the EPN strains more virulent against the target host had greater invasion rates. In the multiplication assay, KKMH1and OCMS1 (SC) produced a greater number of infective juveniles (IJs) (32.1–32.4 x 1000 IJs/ cadaver) in Carcyra cephalonica. Test for tolerance to heat at 40°C for 2 h revealed that KKMH1, TRYH1, KKMH2, KKMS1 and APKS2 were highly tolerant (>85% survival). IJs exposed to ambient room conditions (27–29°C; 65–70% r.h.) for 2 h showed that APKS2, OCMS1 and KKMS1 were more tolerant (68–69% survival) of rapid desiccation than others. APKS2, KKMS1 and KKMH1 showed better survival (70–73%) in slow desiccation assay when exposed to 25°C with 97% r.h. for 72 h, followed by 25°C with 93% r.h. for 48 h. The H. bacteriophora KKMH1 and S. carpocapsae APKS2 performed best in nine traits out of ten tested, followed by H. bacteriophora TRYH1, which performed best for six traits. It is suggested that the EPN strains KKMH1 and APKS2 could be deployed for a cotton bollworm management program after testing their performance under field conditions.  相似文献   

12.
Imidacloprid has been used as a key insecticide for controlling sucking insect pests of cotton, whereas Spodoptera litura also has been indirectly exposed to this insecticide in Pakistan. To evaluate the risk of resistance evolution and to develop a better resistance management strategy, a field collected population was selected with imidacloprid in the laboratory. Thereafter, fitness cost, realized heritability and cross resistance of imidacloprid resistance in S. litura were investigated. After 14 generations of selection with imidacloprid, S. litura developed a 137.48-fold resistance to the insecticide. Bioassay revealed that this strain showed cross-resistance to acetamiprid (RR 8.52) and a little to lamdacyhalothrin (1.92) but negative cross-resistance was found to methomyl (−0.19). The resistant strain had a relative fitness of 0.38, with substantially lower rates of larval survival, larval duration, male pupal duration, development time, emergence rate of healthy adults, fecundity, hatchability, and prolonged larval and pupal duration. Mean relative growth rate of the larvae, intrinsic rate of population increase, and biotic potential was lower for the selected populations. The estimated realized heritability (h2) of imidacloprid resistance was 0.15 in the resistant strain of S. litura. Development of the resistance may cost significant fitness for the resistant population. This study provided valuable information for further understanding the impact of imidacloprid resistance on physiological parameters of S. litura and for facilitating the development of resistance management strategies.  相似文献   

13.
The present study assessed the insecticidal potential of purified Bowman-Birk proteinase inhibitors from red gram (RgPI) and black gram (BgPI) towards lepidopteran insect pests. Both RgPI and BgPI showed remarkable inhibitory activity against midgut trypsin-like proteinases of Achaea janata. While, BgPI showed moderate to low inhibitory activity towards the midgut trypsin-like proteinases of Helicoverpa armigera, Spodoptera litura, Papilio demoleus, Amsacta albistriga, Corcyra cephalonica, Bombyx mori and Daphnis nerii, RgPI showed low to negligible inhibitory activity. The isoinhibitors of RgPI and BgPI were stable in presence of trypsin and chymotrypsin of bovine pancreatic origin, as well as larval midgut proteinases of A. janata, H. armigera and S. litura. The midgut trypsin-like proteinases of A. janata and H. armigera as well as midgut trypsin- and chymotrypsin-like proteinases of S. litura were susceptible to inhibition by RgPI and BgPI. Feeding assays displayed a dose-dependent decrease in body weight and survival rate of these larvae with increasing concentration of inhibitors supplemented in the diet. RgPI displayed significant reduction in body weight and survival rate of A. janata larvae compared with BgPI. Conversely, BgPI showed significant reduction in body weight of S. litura larvae compared with RgPI.  相似文献   

14.
The effects of Isaria farinosa (Holm.) and Beauveria bassiana (Balsamo) on adult stages of sunn pests Eurygaster integriceps Puton and Eurygaster austriaca (Schrk.) were investigated at 27±1°C, 95% r.h. and 16L:8D in the laboratory. Two concentrations, 1×106 and 1×108 conidia ml-1, were used. Mortality of inoculated and non-inoculated adults was counted at 6, 9 and 12 days after treatment. Beauveria bassiana caused higher mortality of both species than I. farinosa. Neither caused significantly high mortality at 1×106 conidia ml-1. Both were more pathogenic at 1×108 conidia ml-1 and caused more than 85% mortality 12 days post treatment. Both were more pathogenic to E. austriaca.  相似文献   

15.
Two sources of resistance to Rice yellow mottle virus were challenged in host passage experiments. Pronounced changes in pathogenicity occurred over serial passages of virus isolates inoculated to partially or highly resistant cultivars. The changes encompassed the known existing pathogenic variability of field isolates. Ultimately, the high resistance of the Oryza indica cv. Gigante was overcome and the partial resistance of the O. sativa japonica cv. Azucena broke down. The effect was resistance-specific as different isolates overcame partial and high resistance, and may also be allele-specific as different isolates overcame the resistance of cultivars carrying the same resistance gene. The ability of isolates to break resistance was not linked to a high initial pathogenicity of the isolates and did not result in higher virus content in the infected plants. Implications for resistance breeding and deployment are discussed.  相似文献   

16.
Resistance in Spodoptera litura (Fabricius) has been attributed to enhanced detoxification of insecticides by increased levels of esterases, oxidases and/or glutathione S-transferases. Enzyme inhibiting insecticide synergists can be employed to counter increased levels of such enzymes in S. litura. Dihydrodillapiole induced synergism of pyrethroid toxicity was examined in the laboratory-reared third instar larval population of S. litura collected in Delhi (susceptible), and Guntur (resistant) region of Andhra Pradesh, India. The Guntur population was found to be 7.04 and 10.19 times resistant to cypermethrin and lambdacyhalothrin, respectively. The activity of cypermethrin, lambdacyhalothrin and profenophos against susceptible and resistance populations of S. litura, was gradually increased when used along with a plant-derived insecticide synergist dihydrodillapiole. The α-naphthyl acetate hydrolysable esterase activity in Delhi population was less as compared to the Guntur population. Resistance associated esterases in Delhi population were inhibited by pre-treatment with dihydrodillapiole. The esterase level in insect was instantly reduced initially, sustained for about 3 h and equilibrated at 4 h post treatment. The esterase activity of Guntur population was increased to 1.28 μmoles/mg/min at 2 h post treatment and subsequently reduced to lower than 0.70 μmoles at 4-12 h post treatment. The variation in esterase activity is suggestive of its homeostatic regulation in test populations. Dihydrodillapiole thus caused significant reduction of resistance in S. litura to cypermethrin, lambda cyhalothrin and profenophos.  相似文献   

17.
The tobacco cutworm, Spodoptera litura (Lepidoptera: Noctuidae) (Fabricius), is a polyphagous pest which has developed physiological resistance against a number of known insecticides. In order to reduce the load of synthetic insecticides, ecofriendly alternative strategies are needed. The present studies were conducted to evaluate the insecticidal potential of the endophytic fungus Cladosporium uredinicola isolated from Tinospora cordifolia (Thunb.) on S. litura. Development of S. litura was significantly prolonged when larvae were fed on diet amended with ethyl acetate extract of C. uredinicola at concentrations of 1.25–2.00 μl?g?1. The negative effects of fungal toxin on development of S. litura further resulted in a significant reduction in adult emergence, longevity and reproductive potential at higher concentrations. A significantly higher number of adults showed morphological deformities when larvae were fed on diet amended with 2.00 μl?g?1 concentration. The inhibitory effects on growth and development of S. litura indicate toxicity of ethyl acetate extract of C. uredinicola, which is further evidenced by reduced food utilization by larvae. The antifeedant and toxic effects of ethyl acetate extract of C. uredinicola observed in the present studies can be attributed to a bioactive compound produced by the fungus, so this study provides evidence that C. uredinicola isolated from T. cordifolia possesses anti-insect properties and may play an important role in protecting plants against insect pests.  相似文献   

18.
为明确草地贪夜蛾Spodoptera frugiperda的捕食性天敌——叉角厉蝽Eocanthecona furcellata在全球的潜在地理分布,基于叉角厉蝽在全球已有的历史分布记录,结合环境数据,采用MaxEnt生态位模型结合GIS技术对其在全球范围的适生区进行分析。结果显示,最暖季降水和最冷季平均温度是影响叉角厉蝽分布的主要环境因素。预测的叉角厉蝽在各个洲均可能发生,适生区集中分布在亚洲东部、东南亚大部、印度半岛东部、非洲南部东西沿海岸地区、南美洲中部地区及澳洲北部沿海岸地区。表明叉角厉蝽适生性较强,可以充分利用其捕食性释放到田间用于生物防治。  相似文献   

19.
The effects of azadirachtin (AZA) and nucleopolyhedrovirus (NPV) on midgut enzyme activity in Spodoptera litura Fabricius (Lepidoptera: Noctuidae) (Tobacco cutworm) were evaluated. Gut enzyme activities were decreased by AZA and NPV individually and in combination. When S. litura larvae were fed a diet of castor leaves treated with AZA and NPV in bioassays, gut enzyme—acid phosphatases, alkaline phosphatases, adenosine triphosphatases, and lactate dehydrogenase—activities were decreased. There were statistically significant differences (P ? 0.05) in enzyme activities between combined and individual treatment. A synergistic effect of botanical insecticides and virus was found when combined in low doses. These effects are most pronounced in early instars. Maximum weight loss (59-72%) occurred, when AZA and NPV were combined.  相似文献   

20.
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