松毛虫赤眼蜂两性生殖品系和孤雌产雌品系在不同品种柞蚕卵中的寄生和生长发育表现

【目的】明确两性生殖品系和孤雌产雌品系松毛虫赤眼蜂Trichogramma dendrolimi在不同品种柞蚕Antheraea pernyi卵中的寄生及发育表现,为以柞蚕卵为替代寄主更好地规模化繁育赤眼蜂提供依据。【方法】测定两性生殖品系和孤雌产雌品系雌蜂在6个品种柞蚕卵［抗大(KD)、大四(DS)、高新(GX)、988(NEE)、青大(QD)和特大(TD)］上的寄生率、子代蜂窝蜂数(单窝羽化子代蜂数)和子代蜂雌性比等生物学指标,以及6个品种柞蚕卵的质量指标(单卵湿重、蛋白质含量、总糖含量和甘油三酯含量);利用主成分分析揭示柞蚕卵质量指标与赤眼蜂生物学指标间的相关性。【结果】NEE品种柞蚕卵育出的两性品系松毛虫赤眼蜂子代蜂个体显著大于除KD和QD品种以外的其他柞蚕品种卵育出的两性品系子代蜂。柞蚕品种对两性品系松毛虫赤眼蜂的寄生率、子代蜂窝蜂数和子代蜂雌性比均无显著影响。在孤雌产雌品系松毛虫赤眼蜂中,KD品种柞蚕卵育出的松毛虫赤眼蜂子代蜂窝蜂数最多,显著高于NEE和QD品种育出的子代蜂窝蜂数,但与DS, GX和TD品种育出的子代蜂窝蜂数相比无显著差异。柞蚕品种对孤雌产雌品系松毛虫赤眼蜂的寄生率和子代蜂个体大小均无显著影响。TD品种柞蚕卵的蛋白质含量最高,显著高于除GX品种以外的柞蚕品种。KD品种柞蚕卵的总糖含量和QD品种柞蚕卵的甘油三酯含量最高,均分别显著高于其余柞蚕品种。主成分分析表明,两性品系松毛虫赤眼蜂寄生率、柞蚕卵蛋白质含量和甘油三酯含量均与柞蚕卵总糖含量呈负相关;两性品系松毛虫赤眼蜂子代蜂个体大小和柞蚕卵甘油三酯含量与单卵湿重呈负相关;孤雌产雌品系松毛虫赤眼蜂寄生率和柞蚕卵甘油三酯含量与松毛虫赤眼蜂子代蜂窝蜂数、柞蚕卵总糖含量和单卵湿重呈负相关;孤雌产雌品系松毛虫赤眼蜂子代蜂个体大小和柞蚕卵总糖含量与蛋白质含量呈负相关。【结论】本研究通过筛选适宜两性生殖品系和孤雌产雌品系赤眼蜂繁育的柞蚕卵品种,初步明确了卵内主要营养指标与子代蜂生物学指标间的相关性。研究结果为利用柞蚕卵更好地规模化繁育松毛虫赤眼蜂提供依据与数据支撑。     

短时极端高温对松毛虫赤眼蜂成虫致死作用及子代适合度的影响

极端高温天气事件在高产作物种植区频繁发生,潜在影响了寄生蜂对害虫的防控能力.为明确短时极端高温对松毛虫赤眼蜂Trichogramma dendrolimi Matsumura成虫致死作用及子代发育适合度的影响,本研究模拟夏季田间最高气温,以42℃高温处理松毛虫赤眼蜂成蜂0.5h和1 h,统计并观测了各处理条件下母代蜂致死率、繁殖力、子代蜂寿命、羽化率、性比和畸形率.结果显示:短时高温对松毛虫赤眼蜂有致死作用,表现为雌、雄蜂直接死亡及子代羽化率降低.42℃处理1 h,雌、雄蜂死亡率分别为40.28％和58.25％.短时极端高温导致松毛虫赤眼蜂子代适合度降低,表现为雌蜂寿命缩短、繁殖力下降,子代蜂畸形率增加及子代蜂雄性比上升.结果表明,短时极端高温对松毛虫赤眼蜂适合度产生负面影响,降低种群数量.本研究为夏季田间释放松毛虫赤眼蜂提供重要理论依据.     

Factors affecting the bionomics of the eastern African egg parasitoid Trichogramma bournieri Pintureau & Babault (Hymenoptera: Trichogrammatidae)

The trichogrammatid Trichogramma bournieri Pintureau & Babault is a polyphagous parasitoid of eggs of several cereal stemborer species in eastern Africa. The effects of host species, host age and duration of host deprivation on the performance of the parasitoid were studied in the laboratory. Host acceptance and suitability were tested using five stemborer species. The noctuids Sesamia calamistis Hampson, Sesamia nonagrioides (Lefebvre), Busseola fusca (Fuller) the crambid Chilo partellus (Swinhoe) and the pyralid Eldana saccharina Walker were successfully parasitized by T. bournieri. Parasitism, number of progeny and developmental time varied significantly with host species. The eggs of S. calamistis and B. fusca were the most suitable, whereas those of E. saccharina were the least suitable. While parasitism and number of progeny tended to decrease with age of hosts, there were no significant differences in sex ratio. Longevity of the parasitoid increased with increase in deprivation of hosts from 0 to 12 days. Average lifetime fecundity per female decreased, indicating resorption of eggs.     

Overwintering of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) within target and non-target host eggs

Trichogramma ostriniae was imported into the USA from China and it continues to be evaluated as a biological control agent against the European corn borer and other lepidopteran pest species. A natural enemy's ability to overwinter is a facet of its biology with important ramifications for biological control and non-target effects. Thus, studies were conducted to examine the ability of the introduced egg parasitoid to survive over winters in central New York State. Eggs of Ostrinia nubilalis, Ephestia kuehniella, Trichoplusia ni, Helicoverpa zea and Utetheisa ornatrix were subjected to parasitism by adult T. ostriniae and then placed out of doors and exposed to winter conditions. For trials initiated in 2003 and 2004, the adult parental wasps were exposed to a diapause-inducing photoperiod and temperature regime in the laboratory; in 2010, parental wasps were conditioned out of doors and prior to the onset of winter conditions. Emergence of their progeny was monitored over time by taking aliquots of parasitised eggs, and holding them under warm conditions until emergence was complete. The level of wasp emergence generally displayed a decline followed by gradual increase until spring. Levels of overwintering ranged from 1% for O. nubilalis to 76% for E. kuehniella, and logistic regression indicated that the odds of overwintering was dependent on the year, host species, time out of doors and varied over exposure time depending on host. The potential to overwinter in New York was further confirmed by positive identification of T. ostriniae from naturally occurring O. nubilalis eggs collected from field sites where augmentative releases had been made in previous years.     

室内外评价在黄淮海夏玉米区释放玉米螟赤眼蜂防治亚洲玉米螟的可行性

为了评价在黄淮海夏玉米区释放米蛾卵繁育的玉米螟赤眼蜂Trichogramma ostriniae防治亚洲玉米螟Ostrinia furnacalis的可行性,本试验在室内组建了玉米螟赤眼蜂在亚洲玉米螟卵上的实验种群生命表的基础上,在河南省鹤壁市滑县测定了玉米螟赤眼蜂对亚洲玉米螟的防治效果,筛选出了具有较好防治效果的释放密度和释放方法。结果显示,米蛾卵繁育的玉米螟赤眼蜂在亚洲玉米螟卵上的净生殖力R0为9.8240,单雌平均产雌率R0'为12.6256,2013年在河南省鹤壁市滑县释放玉米螟赤眼蜂能使亚洲玉米螟虫口密度减退73.91%,释放密度为2.25×105头/hm2。2014年在鹤壁市淇滨区钜桥镇采用传统的人工挂卡和新型的无人机释放玉米螟赤眼蜂,亚洲玉米螟虫口密度减退54.55%-68.16%。结果表明,在黄淮海夏玉米区释放米蛾卵繁育的玉米螟赤眼蜂防治玉米螟是可行的。     

温度对麦蛾卵繁育的玉米螟赤眼蜂发育和生殖的影响

玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen是玉米螟的重要卵寄生性天敌,控制适宜的温度有利于室内大规模繁育。本试验以麦蛾卵为寄主,研究了不同温度(18℃、20℃、23℃、25℃、28℃、30℃、33℃、36℃)对玉米螟赤眼蜂的寿命、生殖力、子代羽化率和发育历期的影响。结果表明,20℃-25℃条件下雌蜂寿命最长,达7.9-9.0 d。在18℃-30℃亲代生殖力和子代羽化率无显著差异,亲代产卵量为40.9-61.7粒;羽化率为74.31%-84.22%。玉米螟赤眼蜂从卵到羽化的发育历期随温度的升高而显著缩短,由18℃时的22.6 d缩短至33℃的7.0 d。36℃时,雌蜂的寿命仅为0.56 d,且不能进行正常的生殖活动。因此,室内用麦蛾卵大规模繁育玉米螟赤眼蜂,适宜的温度为28℃-30℃;仅保存蜂种时,可选用温度18℃-20℃。     

艾叶精油对玉米螟赤眼蜂的影响及两者对米蛾的联合作用

玉米螟赤眼蜂是生物防治中一种重要的天敌昆虫,为探明艾叶精油对玉米螟赤眼蜂的影响及两者对米蛾的联合防治效果,本文研究了艾叶精油熏蒸、触杀、驱避活性对玉米螟赤眼蜂的影响及艾叶精油和玉米螟赤眼蜂对米蛾的联合作用。结果表明,艾叶精油熏蒸和触杀处理对玉米螟赤眼蜂卵具有明显影响,寄生在米蛾卵上的玉米螟赤眼蜂卵经0.1、0.2、0.3、0.4、0.5、0.6μg/cm3艾叶精油熏蒸处理72h后玉米螟赤眼蜂的羽化率分别为56.67%、49.33%、44.00%、33.33%、26.00%和14.67%;寄生在米蛾卵上的玉米螟赤眼蜂卵经100、200、300、400、500、600mg/L艾叶精油触杀处理72h后玉米螟赤眼蜂的羽化率分别为54.00%、45.33%、38.00%、28.67%、18.00%和6.00%,均与对照组表现出显著性差异。艾叶精油驱避活性对玉米螟赤眼蜂成蜂也有明显的影响,300mg/L艾叶精油对玉米螟赤眼蜂的驱避率79.05%,随着时间间隔和距离间隔的增加,这种影响作用降低;联合应用艾叶精油与玉米螟赤眼蜂时先释放玉米螟赤眼蜂,24h后再滴加艾叶精油的防治效果最佳,米蛾的死亡率可高达96%。     

Patch time allocation in male parasitoids

Abstract 1. Patch time allocation has been mostly studied in female parasitoids exploiting patches of hosts. Different parameters such as oviposition, host encounters, patch quality, etc. have been repeatedly shown to modify the time females invest on hosts. 2. Male parasitoids are expected to maximise their lifetime fitness by maximising the number of females inseminated during their life. Because they can be sperm and/or time limited, they should optimise their time allocation on emergence patches. 3. Patch time allocation thus appears to be an important question for both male and female parasitoids. 4. In this study, we determined the parameters used by males of the egg parasitoid Trichogramma turkestanica to decide when to leave the emergence patch. Among the different patch‐leaving parameters tested, only contacts with parasitised hosts and presence of virgin females significantly influenced the patch‐leaving tendency. 5. Our results suggest that males express behaviours that could enable them to optimise their patch exploitation time, as females do, but using different strategies.     

Wolbachia对赤眼蜂的性别调控机制及生理影响

沃尔巴克氏体(Wolbachia)是广泛分布于节肢动物生殖组织内的一类共生细菌。它们通过共生诱导宿主赤眼蜂的产雌孤雌生殖,在生物防治上具有重要意义。文章概述了Wolbachia在赤眼蜂中的分布状况,对赤眼蜂的性别调控机制,在赤眼蜂种群中的传播及限制因素,以及对赤眼蜂适合度的影响。