Valigurová A, Michalková V, Koník P, Dindo M L, Gelnar M, Vaňhara J
Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic.
Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 06 Bratislava, Slovakia.
Bull Entomol Res. 2014 Apr;104(2):203-12. doi: 10.1017/S0007485313000655. Epub 2013 Dec 20.
The tachinid fly Exorista larvarum (L.) (Diptera: Tachinidae) is a polyphagous larval endoparasitoid that deposits its eggs on the host exoskeleton of lepidopteran and tenthredinid larvae. The attachment of larval E. larvarum and the formation of the respiratory funnel were studied during infestation in the last larval instar of the wax moth, Galleria mellonella (L.) (Lepidoptera: Pyralidae). The tachinid larvae burrow through the host integument after hatching, using their robust cephalopharyngeal skeleton, leaving a dark spot at the point of their penetration as a result of host cuticle melanization. Endoparasitoid penetration induces the host cellular defence, resulting in the formation of a haemocyte capsule consisting of multi-cellular sheaths. This enveloping capsule later undergoes melanization, which is mostly obvious towards the posterior part of the endoparasitoid. The endoparasitoid uses the host encapsulation response to build a respiratory funnel from the modified host integument, leading to the host surface. The encapsulated larva remains attached to the respiratory funnel via an anal hook and cuticular spines until fully developed. Additional immunohistochemical analyses were used to study host-parasitoid interactions. Indirect immunofluorescence showed no labelling of potential tachinid antigens and confirmed no effect on the surrounding host tissues. A simulated parasitization with coated polybead microspheres revealed the mortal impact of tachinid antigens to the host. Hosts injected with antigen-coated polybeads died as a consequence of an acute and extensive immunological response to the tachinid antigens and not due to the trauma caused by foreign objects inside their body.
寄蝇科昆虫家蚕追寄蝇（Exorista larvarum (L.)，双翅目：寄蝇科）是一种多食性幼虫内寄生蜂，它将卵产在鳞翅目和叶蜂科幼虫的宿主体外骨骼上。本研究在大蜡螟（Galleria mellonella (L.)，鳞翅目：螟蛾科）末龄幼虫被寄生期间，对家蚕追寄蝇幼虫的附着以及呼吸漏斗的形成进行了研究。寄蝇幼虫孵化后利用其坚固的头咽骨骼钻透宿主表皮，由于宿主表皮黑化，在穿透点会留下一个黑点。内寄生蜂的穿透引发宿主细胞防御，导致形成由多细胞鞘组成的血细胞包囊。这个包囊随后会发生黑化，在内寄生蜂后部最为明显。内寄生蜂利用宿主的包囊反应，由修饰后的宿主表皮构建一个通向宿主表面的呼吸漏斗。被包囊的幼虫通过肛门钩和表皮刺与呼吸漏斗相连，直至发育完全。另外还采用免疫组织化学分析来研究宿主 - 寄生蜂的相互作用。间接免疫荧光显示未标记潜在的寄蝇抗原，证实对周围宿主组织无影响。用包被的聚苯乙烯微球模拟寄生揭示了寄蝇抗原对宿主的致命影响。注射了抗原包被聚苯乙烯微球的宿主因对寄蝇抗原产生急性广泛免疫反应而死亡，而非因体内异物造成的创伤。
