Microorganism-associated variation in host infestation efficiency in a parasitoid wasp,Trichogramma bourarachae (Hymenoptera: Trichogrammatidae)

InTrichogramma bourarachae (Hymenoptera: Trichogrammatidae), the infestation efficiency presents important variation among strains: 60 eggs/5 days/female in the High (H) strain and 25 eggs/5 days/female in the Low (L) strain. Crosses show that between-strains variation is inherited by the matrocline route. Antibiotic and heat treatments reduce infestation efficiency in the H strain and have no effect on the L strain. The hypothesis of cytoplasmic-symbiotic microorganisms accounting for the higher infestation efficiency in the H strain is supported by microscopic observations. The origin and the significance of this between-strains variation are discussed.     

Effects of diapause and host species on some morphometric characters inTrichogramma (Hym.: Trichogrammatidae)

Adult morphology ofTrichogramma is modified by environmental conditions during the preimaginal development. For instance, the low temperatures inducing diapause cause a decrease of the ratio length of longest seta on male flagellum/width of flagellum inT. evanescens. The species of the host also influences numerous body ratios. So, in females, the development of tibiae with regard to wings is more important withScotia ipsilon than withGalleria mellonella. These results confirm the necessity of performing comparative morphological studies on individuals reared in the same conditions.     

利它素对赤眼蜂寄主搜寻行为的影响

室内检测了赤眼蜂对其寄主的鳞片提取物(利它素)引起的滞留搜寻时间反应.结果表明广赤眼蜂对欧洲玉米螟利它素比亚洲玉米螟的滞留搜寻反应时间明显延长(P=0.0001),并表现出对寄主种类的一定选择性.     

利用松毛虫赤眼蜂防治蕃茄地棉铃虫试验

本试验是为探求松毛虫赤眼蜂在蕃茄地防治棉铃虫的可能性及其效果。通过试验表明:在放蜂区,松毛虫赤眼蜂对棉铃虫卵的寄生率平均为82.3%;蕃茄果实被害率压低到1.60%——2.83%以下。绝对防治效果为70.76%——82.68%,利用松毛虫赤眼蜂防治蕃茄地棉铃虫效果良好。     

舟蛾赤眼蜂(Trichogramma closterae)雌性触角的扫描电镜观察

一、引言赤眼蜂的雄体可用外生殖器特征来鉴定种类,而雌性没有稳定的性状作为鉴定的依据,因此,作者曾用扫描电镜研究了松毛虫赤眼蜂(Trichogramma dendrolimi)和玉米螟赤眼蜂(T.ostriniae)的雌性触角,发现这两种蜂分布在触角上i型感器的数目及形     

松毛虫赤眼蜂(Trichogramma dendrolimi)和玉米螟赤眼蜂(T.ostriniae)雌性触角的扫描电镜观察

用扫描电镜观察了松毛虫赤眼蜂和玉米螟赤眼蜂的雌性触角,得到两种蜂触角上的感受器各有九种。发现分布在棒节腹面“探索区”的i型感器数目和形状在两种蜂之间有明显差异,因此具有鉴定种类的价值。用光学显微镜也能分辨出这种感器。本文详细描述了各种感器的细微结构和形态特征。     

Molecular Identification of a Wolbachia endosymbiont in Trichogramma dendrolimi

Wolbachia is a common and widespread group of bacteria found in arthropods. These bacteria have evolved various mechanisms for manipulating reproduction of their host. The presence of Wolbachia in a lab strain of the arrhenotokous species Trichogramma dendrolimi was observed by the amplification and sequencing of part of the wsp gene. Aligning the resulting sequences with already published ones, the phylogenetic relationships between Wolbachia found in Trichogramma dendrolimi and in other Trichogramma wasps was established, and the phylogenetic relationships of Wolbachia in Trichogramma were not congruent with their hosts Trichogramma. Some factors contributing to this uncongruence are discussed here.