Laboratoire de Biologie des Entomophages, EA 3900 BioPI, Université de Picardie-Jules Verne, 33 rue Saint Leu, 80039 Amiens cedex, France.
J Insect Physiol. 2010 Jan;56(1):35-41. doi: 10.1016/j.jinsphys.2009.09.001.
Asobara japonica (Braconidae) is an endophagous parasitoid developing in Drosophila larvae. The present study shows that A. japonica was never encapsulated in Drosophila melanogaster, and that it caused an overall inhibition of the host encapsulation reaction since injected foreign bodies were never encapsulated in parasitized hosts. Both the number of circulating hemocytes and the phenoloxidase activity decreased in parasitized larvae, and the hematopoietic organ appeared highly disrupted. We also found that A. japonica venom secretions had atypical effects on hosts compared to other braconid wasps. A. japonica venom secretions induced permanent paralysis followed by death of D. melanogaster larvae, whether injected by the female wasp during an interrupted oviposition, or manually injected into unparasitized larvae. More remarkably, these effects could be reversed by injection of ovarian extracts from female wasps. This is the first report that the venom of an endophagous braconid parasitoid can have a deadly effect on hosts, and moreover, that ovarian extracts can act as an antidote to reverse the effects of the wasp's venom. These results also demonstrate that A. japonica secretions from both venom gland and ovary are required to regulate synergistically the host physiology for the success of the parasitoid.
日本黄胡蜂（Braconidae）是一种内寄生性的寄生蜂，在果蝇幼虫体内发育。本研究表明，日本黄胡蜂从未在黑腹果蝇中被包裹，并且它导致了宿主包裹反应的整体抑制，因为注入的异物从未在寄生的宿主中被包裹。寄生幼虫的循环血细胞数量和酚氧化酶活性均下降，造血器官出现高度破坏。我们还发现，与其他 Braconid 黄蜂相比，日本黄胡蜂毒液分泌物对宿主具有非典型作用。日本黄胡蜂毒液分泌物会导致黑腹果蝇幼虫永久性瘫痪，随后死亡，无论是雌性黄蜂在中断产卵期间注射，还是手动注射到未寄生的幼虫中。更值得注意的是，这些影响可以通过注射雌性黄蜂的卵巢提取物来逆转。这是第一个报道内寄生性 Braconid 寄生蜂的毒液对宿主具有致命影响的报告，而且卵巢提取物可以作为解毒剂来逆转黄蜂毒液的作用。这些结果还表明，日本黄胡蜂的毒液腺和卵巢分泌物都需要协同调节宿主生理，以确保寄生蜂的成功。
