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1.
The attraction ofTrichogramma platneri Nagarkatti (Hymenoptera: Trichogrammatidae) to eggs of two lepidopterous avocado pests,Boarmia sel-enaria (Schiffermüller) (Geometridae) andCryptoblabes gnidiella (Millière) (Phycitidae), was evaluated in olfactometer tests. The mobility of the wasp as measured by a mobility index was 0.6 for males and 1.8 for females; the males had a lower mobility and a lower search capacity index than the females. Frozen and fresh youngB. selenaria eggs had the greatest attraction forT. platneri, which diminished with increasing age of the eggs. The eggs ofC. gnidiella were also attractive to the parasitoid. Contribution from the Agricultural Research Organization. No. 2704-E, 1989 series.  相似文献   

2.
The relationship between different oxygen tensions and exposure times producing 95% mortality, and loss in weight of three stored-product insects at 54% R.H. and 26°C, was determined.Ephestia cautella (Wlk.) pupae andTribolium castaneum (Herbst) adults reacted in a similar pattern: the lower the oxygen concentration, the shorter the exposure time needed to produce 95% mortality, and the higher the rate of loss in weight. The response ofSitophilus oryzae (L.) adults was different: there was greater sensitivity at 1% oxygen than at the lower or higher levels of oxygen tested. A relationship was demonstrated between low oxygen tensions (0–5%) and the relative humidity of the environment for producing a lethal atmosphere forE. cautella pupae andT. castaneum adults.  相似文献   

3.
The effectiveness of a commercial preparation ofBacillus thuringiensis Berliner (Dipel) against eggs and larvae ofBoarmia (Ascotis) selenaria Schiff. of different age was examined in laboratory and in field tests. The mortality rate ofB. selenaria was proportional to the concentration ofB. thuringiensis and inversely related to the age of the treated larvae. In neonate larvae, 100% mortality was obtained even with a low concentration (0.5%). Egg hatch was not affected, but the survival rate of larvae hatched from treated eggs was very low (2.2%). No phytotoxicity of the commercial microbial preparation was observed on fruit or leaves of avocado. High doses ofB. thuringiensis persisted on avocados, probably because of specific conditions:i.e., absence of rainfall, moderate temperatures and limited penetration of sunlight. Tests carried out in large commercial orchards, using motor-guns and helicopters, yielded good results.  相似文献   

4.
The compatibility and protectant potential of Calneem® oil derived from the neem tree Azadirachta indica and two parasitoids, Habrobracon hebetor and Venturia canescens, for the control of the rice moth Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) and the tropical warehouse moth Cadra cautella Walker (Lepidoptera: Pyralidae) in stored rice and wheat, were evaluated in the laboratory. Calneem® oil (= neem oil) is a biopesticide produced, registered and marketed in Ghana by AQUA AGRIC Community Projects (AACP/Caldor Ghana Ltd., Tema). It contains 0.3% azadirachtin as its major active ingredient. The oil was emulsified with water using 0.07% soap. Fourth instar moth larvae were held in grain treated with neem oil only, grain treated with one of the parasitoids only, grain treated with a combination of neem and one of the parasitoids, and a control with untreated grain. Neem oil was applied at concentrations from 5,000 to 30,000 ppm. All samples were kept in growth cabinets maintained at 25°C and 65–70% r.h. Adult emergence was recorded after 4 weeks. Parasitoid or neem treatments alone reduced the emergence of C. cephalonica and C. cautella. In general, parasitoid releases were as effective as a combination of neem oil and parasitoids. At the lowest dose, 5,000 ppm, the combination of neem and parasitoid was more effective than the neem alone. The number of adults of H. hebetor and V. canescens that emerged in rice containing either parasitoids alone or in combination with neem oil was similar. This indicates minimal or no adverse effect of neem oil on the two parasitoids. It is thus possible to incorporate neem oil in a well-designed pest management program with parasitoids.  相似文献   

5.
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   

6.
The frequency of encapsulation of eggs ofAnagyrus pseudococci (Girault) (Hymenoptera: Encyrtidae) by four mealybug species:Planococcus citri (Risso),PL vovae (Nasonov),Pl. ficus (Signoret) andPseudococcus cryptus Hempel (=citriculus Green), was studied under controlled laboratory conditions. The aggregate percentage of encapsulated eggs (AE) and the percentage of efficient encapsulation (EE) (= percent parasitized mealybugs wherein encapsulation prevented the development of all parasitoid larvae) byPl. citri andPl. vovae did not differ significantly (39.0%vs 38.2% AE and 15.4%vs 17.6% EE, respectively), but was significantly higher than inPs. cryptus (16.2% AE and 5.4% EE). Encapsulation byPl. vovae was significantly higher than byPl. ficus (38.2%vs 20.1% AE and 17.6% vs 7.7% EE, respectively). Neither the host plant nor the rearing temperature significantly affected the incidence of parasitoid encapsulation. It is suggested thatA. pseudococci displays a relatively low physiological adaptation toPl. citri; thus, in a citrus grove, for example,ca 40% of the parasitoid eggs might be lost due to encapsulation. The question of a possible association between encapsulation and host—parasitoid relationships among the mealybugs studied andA. pseudococci, is discussed.  相似文献   

7.
Coleomegilla maculata DeGeer is an omnivorous lady beetle that feeds on natural or alternative prey and artificial foods, which allows its laboratory rearing for use on augmentative biocontrol. In addition, C. maculata may supplement its diet with pollen and nectar, which helps in its conservation in agroecosystems. This study aimed to evaluate if Apiaceous flowers (Anethum graveolens L. and Coriadrum sativum L.), with and without alternative prey [eggs of Ephestia kuehniella (Zeller) or larvae of Drosophila melanogaster Meigen] or an artificial food (aqueous solution of honey), may guarantee the survival and complete development of the immature and adult stages of C. maculata in the laboratory. The immature stages developed only when Apiaceous flowers were offered with E. kuehniella eggs. The food with only one of the alternative prey (moth eggs or fly larvae) or moth eggs + honey solution resulted in fertile adults; however, the number of eggs/cluster was greater for the foods with E. kuehniella eggs + honey solution, A. graveolens flowers, or only D. melanogaster. Foods comprising only the two Apiaceous species, only the honey solution, or only water resulted in larval development up to a specific instar. Adults of C. maculata also survived on these foods, but there was no oviposition. The foods of the two Apiaceous species produced heavier adults only when associated with E. kuehniella eggs. The results indicate that the zoophytophagous habit of C. maculata should be considered in conservation biocontrol programs aimed at using this lady beetle to control crop pests.  相似文献   

8.
Dactylopius opuntiae is an insect pest of cactus which is currently causing severe damage to cactus crops in Morocco. It was first observed in 2014 in the Sidi Bennour region 120 km northwest of Marrakech, and has spread very quickly to destroy the prickly pear cactus crops (Opuntia ficus‐indica (L.) Miller) in several regions of country, causing very heavy economic losses. To control this pest, the predatory potential of eleven species of native Moroccan ladybird predators was investigated under laboratory conditions at 26 ± 2°C, 60 ± 10% RH and a 12 h light:12 h dark regime. The experiments were conducted in no‐choice feeding tests (only eggs, first instar or second instar of mealybugs were offered at one time) and free‐choice feeding tests (eggs and first and second instar larvae were offered simultaneously). In the no‐choice feeding tests, Exochomus nigripennis, Chilocorus bipustulatus and Chilocorus politus consumed the highest mean number of mealybug eggs and first instars, and the highest mean number of second instars was consumed by Hippodamia convergens. In the free‐choice feeding tests the highest mean number of mealybug eggs was eaten by Chilocorus bipustulatus and Chilocorus politus and Hippodamia convergens consumed the highest mean number of first and second instars of the mealybug.  相似文献   

9.
螺虫乙酯对B型烟粉虱毒力及部分生物学参数的影响   总被引：3，自引：1，他引：2  
为系统评价新药剂螺虫乙酯(spirotetramat)对B型烟粉虱(Bemisia tabaci biotype B)的生物活性及生物学参数的影响,采用浸渍法测定了螺虫乙酯及对照药剂吡虫啉对B型烟粉虱各个虫态的室内毒力、成虫寿命、产卵量及所产卵孵化率的影响。结果表明,螺虫乙酯对2龄若虫毒力最高,LC50为4.07 mg/L,为吡虫啉的2.73倍,对卵及成虫毒力较低,且显著低于吡虫啉;12.5 mg/L螺虫乙酯处理后,成虫寿命为17.3天,较空白对照显著缩短,吡虫啉与空白对照无显著差异;12.5 mg/L螺虫乙酯处理后平均产卵量为5.0粒,所产卵的平均孵化率为3.23%,显著低于空白对照和吡虫啉处理,吡虫啉与空白对照无显著差异;100 mg/L螺虫乙酯处理24 h后对烟粉虱成虫驱避率为52%,驱避效果较差。  相似文献   

10.
三种赤眼蜂对灰白蚕蛾的卵龄选择   总被引：2，自引：2，他引：0  
灰白蚕蛾Ocinara varia.是近年来华南地区为害较严重的园林害虫,为筛选有效防治灰白蚕蛾的赤眼蜂种,在室内条件下比较了短管赤眼蜂Trichogramma pretiosum、松毛虫赤眼蜂T.dendroli-mi和暗黑赤眼蜂T.euproctidis对不同卵龄灰白蚕蛾卵的寄生能力和适应能力.结果显示,随寄主卵龄的增加松毛虫赤眼蜂和暗黑赤眼蜂寄生卵数均呈下降趋势,且都在灰白蚕蛾卵龄为6h的卵上寄生卵数最多,分别为15.90粒/雌和12.20粒/雌;而短管赤眼蜂的寄生卵数随寄主卵龄的增加呈先上升后下降趋势,在卵龄为24 h时达最高,为8.25粒/雌;在各卵龄段,松毛虫赤眼蜂的寄生卵数均比其它2种蜂多;当寄主卵龄超过72 h时,3种赤眼蜂的寄生卵数均显著下降.3种赤眼蜂在寄生卵龄为6h的寄生卵上羽化率最高,当卵龄超过72 h时,其羽化率均显著下降.松毛虫赤眼蜂和暗黑赤眼蜂对6h卵龄的灰白蚕蛾卵致死能力最强,而短管赤眼蜂对24 h卵龄的灰白蚕蛾卵致死能力最强.综合分析表明,松毛虫赤眼蜂在灰白蚕蛾卵上的寄生能力和适应能力最好,是灰白蚕蛾的有效天敌.  相似文献   

11.
PH 60-40 is of very high toxicity toSpodoptera littoralis eggs in laboratory experiments; 100% kill was obtained by dipping young eggs in a 0.000 025% a.i. dilution in water of a 5% liquid formulation of the compound.  相似文献   

12.
The effects of the botanical insecticides Biopiren plus, Piresan plus and Neemazal T/S on the predatory mite Amblyseius andersoni (Chant) were tested under laboratory, semi-field, and field conditions. The tests carried out in the laboratory allowed detection of the direct toxicity on eggs and females as well as the effects on fecundity, whereas semi-field trials assessed their residual toxicity. In laboratory and semi-field tests, pyrethrins, particularly Piresan plus, proved to have the highest toxicity with E value, concerning both female mortality and fecundity, of 100% and 45%, respectively. The same product tested in the field only caused a significant reduction in the phytoseiid population shortly after the treatment. The relevant escape rate registered in semi-field tests could explain the lack of phytoseiid eradication in the field after treatment with pyrethrins.  相似文献   

13.
The effects of the botanical insecticides Biopiren plus, Piresan plus and Neemazal T/S on the predatory mite Amblyseius andersoni (Chant) were tested under laboratory, semi-field, and field conditions. The tests carried out in the laboratory allowed detection of the direct toxicity on eggs and females as well as the effects on fecundity, whereas semi-field trials assessed their residual toxicity. In laboratory and semi-field tests, pyrethrins, particularly Piresan plus, proved to have the highest toxicity with E value, concerning both female mortality and fecundity, of 100% and 45%, respectively. The same product tested in the field only caused a significant reduction in the phytoseiid population shortly after the treatment. The relevant escape rate registered in semi-field tests could explain the lack of phytoseiid eradication in the field after treatment with pyrethrins.  相似文献   

14.
Laboratory and nursery tests showed that a 2% neem (Melia azadirachta L.) seed kernel suspension in water was effective as a repellent and ovipositional deterrent for moths of the tobacco caterpillar,Spodoptera litura (F.). The mean number of eggs laid on treated tobacco seedlings was 37 3 as against 1715 on control seedlings. As a consequence of the moths being repelled from the treated plants, they laid more eggs on the cloth and the glass surface in glass jar experiments. Repellency was even more pronounced when the moths were released in treated and untreated nylon-netting-caged nursery beds; the mean number of eggs laid on treated seedlings was then only 749 as against 19,713 in control beds.  相似文献   

15.
松毛虫赤眼蜂对三种农田常用杀虫剂的敏感性   总被引：1，自引：0，他引：1  
为明确常用杀虫剂对松毛虫赤眼蜂Trichogramma dendrolimi的安全性,室内评估了高效氯氰菊酯、阿维菌素和氯虫苯甲酰胺3种药剂对其成蜂的急性毒力以及田间推荐使用剂量对赤眼蜂各发育阶段的间接影响,并模拟自然情况,测定了不同残留期的3种药剂对赤眼蜂存活和寄生能力的影响.结果表明:以LC50进行评估,对松毛虫赤眼蜂毒力最高的为阿维菌素,其次是高效氯氰菊酯,氯虫苯甲酰胺毒力最小;在田间推荐使用剂量下,阿维菌素、高效氯氰菊酯和氯虫苯甲酰胺的安全系数分别为0.017、0.066和69.175;在推荐使用剂量下,氯虫苯甲酰胺处理含有不同发育阶段赤眼蜂的米蛾Corcyra cephalonica卵后,平均羽化率最高为90.43%,其次是高效氯氰菊酯为56.46%,阿维菌素仅为9.84%;接触0~7 d残留期阿维菌素的玉米叶片24 h,松毛虫赤眼蜂全部死亡,无米蛾卵被寄生,但接触3~7 d残留期氯虫苯甲酰胺的玉米叶片,赤眼蜂的死亡率和寄生米蛾卵数量与清水对照无明显差异.表明在实施释放赤眼蜂的害虫综合治理方案中,应尽量避免使用阿维菌素,而氯虫苯甲酰胺对赤眼蜂风险性极低,具有很好的相容性,可以推广使用.  相似文献   

16.
寄主植物对甜菜夜蛾生长发育和消化酶活性的影响   总被引：5，自引：3，他引：2  
通过室内饲养和生化测定,研究了甜菜、玉米和黄瓜3种寄主植物的营养物质及其对甜菜夜蛾幼虫发育、成虫产卵及5龄幼虫体内蛋白质和总氨基酸含量、淀粉酶和脂肪酶活力的影响.结果表明:与取食玉米和黄瓜的个体相比,取食甜菜的甜菜夜蛾,其幼虫期和蛹期较短,分别为11.4天和5.6天;蛹期存活率最高,达100%;成虫寿命较长,为26.3天;单雌产卵量最高,为301.8粒.取食3种寄主植物,甜菜夜蛾5龄幼虫体内的蛋白质含量无差异,但总氨基酸含量差异显著,此外,幼虫体内淀粉酶和脂肪酶活力也存在显著差异,取食甜菜的个体>取食玉米的个体>取食黄瓜的个体.取食不同寄主植物,甜菜夜蛾幼虫的消化酶和脂肪酶活力与其发育适合度呈正相关.  相似文献   

17.
防治棉铃虫的高毒农药替代品种研究   总被引：1，自引：0，他引：1  
采用室内浸卵、浸叶和点滴法以及田间小区试验,对19种杀虫剂防治棉铃虫的作用特点和效果进行了系统研究。室内生物测定结果表明:多杀菌素对棉铃虫卵孵化有较好的抑制作用,90.40 mg/L多杀菌素处理后棉铃虫卵的孵化率仅为42.86%;多杀菌素、甲氨基阿维菌素、高效氯氟氰菊酯、辛硫磷、丙溴磷、毒死蜱和高效氯氰菊酯对棉铃虫初孵幼虫的毒杀作用明显,原药稀释1.0×104~2.0×104倍时可使初孵幼虫死亡率达100%;昆虫生长调节剂——氟啶脲、氟铃脲、甲氧虫酰肼原药稀释1 000倍对棉铃虫初孵幼虫的致死率大于70％,且幼虫的生长受到明显抑制;甲氨基阿维菌素、高效氯氟氰菊酯、多杀菌素、毒死蜱、高效氯氰菊酯、丙溴磷、辛硫磷对低、高龄棉铃虫幼虫均具有较好的毒杀效果。田间小区试验结果表明,甲氨基阿维菌素、高效氯氟氰菊酯、丙溴磷、高效氯氰菊酯作用效果快且防治效果好,尤其是4 000倍甲氨基阿维菌素和5 000倍高效氯氟氰菊酯处理后第三天,其对棉铃虫的致死率达100％;多杀菌素和甲氧虫酰肼作用效果稍差。若在棉铃虫卵高峰期适时施药,供试的6种药剂均可作为防治棉铃虫的高毒农药替代品种。  相似文献   

18.
A microsomal malathion carboxylesterase present in Triatoma infestans eggs was active from the first day of embryonic development. This microsomal egg malathionase (MEM) showed a unique band in polyacrilamide gel electrophoresis (PAGE) when malathion was used as substrate. In vivo metabolism of [14C]malathion during all embryonic development showed a 10% degradation due to carboxylesterases. The in vitro evaluation of the same metabolic pathway catalyzed by the microsomal fraction of T. infestans eggs showed partial inhibition by paraoxon. α- and β-malathion monoacids were identified as the main metabolites of the in vivo and in vitro metabolic pathways. The carboxylesterase band that appeared in PAGE (MEM) from the first day of embryonic development could be the main cause of malathion tolerance in T. infestans eggs.  相似文献   

19.
基于性诱剂监测的梨小食心虫防治指标   总被引：4，自引：1，他引：3  
为明确梨小食心虫性诱剂水盆诱捕器诱蛾量与梨果着卵量的关系,建立一种简单实用,基于梨小食心虫成虫发生量的防治指标,于2010和2011年在陕西蒲城梨园调查了梨小食心虫在早酥梨上的着卵情况及其与性诱剂水盆诱捕器诱蛾量之间的关系.结果显示,梨小食心虫在梨果胴部的着卵量显著高于其它部位,占总卵量的92.00％;百果卵数、卵果率随果实的增大而增加,直径70mm以上果实的百果卵数和卵果率均显著高于直径65 mm以下的果实.据此建立了诱蛾量与卵果率、百果卵量的回归方程,分析得出当以卵果率1％和百果卵量1粒为防治指标时,基于性诱剂监测的梨小食心虫的防治指标分别为每天每诱捕器2.27和2.32头;以卵果率2％和百果卵量2粒为防治指标时,则分别为每天每诱捕器2.61和2.58头.  相似文献   

20.
S. Ekesi 《Phytoparasitica》2000,28(4):305-310
The effect of volatiles and aqueous extracts of black pepper,Piper guineense; neem seed,Azadirachta indica; garlic bulb,Allium sativum; and onion bulb,Allium cepa on egg viability ofMaruca vitrata Fab. (Lepidoptera: Pyralidae) andClavigralla tomentosicollis Stål (Heteroptera: Coreidae) was evaluated in laboratory experiments. Compared with the other treatments, volatiles of black pepper and garlic bulb were superior in reducing hatch of freshly laid (12-h-old) eggs of both species of insects. Volatiles of onion bulb and neem seed had no effect on egg hatch. When aqueous extracts of the various plant materials were tested at 5%, 10% and 15%, extracts of black pepper, neem seed and garlic bulb caused a severe reduction in egg hatch, with black pepper and garlic bulb providing the highest reduction at all concentrations tested in both insects. When black pepper and garlic bulb were compared at 5% for their activity in relation to egg age, the effect of black pepper decreased with increasing egg age but the performance of garlic was consistent across the various age groups tested in both insects. This result is indicative of the potential of using these plant materials and especially garlic for the management ofM. vitrata andC. tomentosicollis.  相似文献   

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