Down R E, Smethurst F, Bell H A, Edwards J P
Central Science Laboratory, Sand Hutton, York, YO41 1LZ, UK. r.down.csl.gov.uk
Bull Entomol Res. 2005 Apr;95(2):133-44. doi: 10.1079/ber2004343.
Infection of Lacanobia oleracea (Linnaeus) larvae with the microsporidium Vairimorpha necatrix (Kramer) resulted in significant effects on the survival and development of the braconid parasitoid, Meteorus gyrator (Thunberg). Female M. gyrator did not show any avoidance of V. necatrix-infected hosts when they were selecting hosts for oviposition. When parasitism occurred at the same time as infection by the pathogen, or up to four days later, no significant detrimental effects on the parasitoid were observed. However, when parasitism occurred six to eight days after infection, a greater proportion (12.5-14%) of hosts died before parasitoid larvae egressed. Successful eclosion of adult wasps was also reduced. When parasitism and infection were concurrent, parasitoid larval development was significantly faster in infected hosts, and cocoons were significantly heavier. However, as the time interval between infection and parasitism increased, parasitoid larval development was significantly extended by up to two days, and the cocoons formed were significantly (c. 20%) smaller. Vairimorpha necatrix spores were ingested by the developing parasitoid larvae, accumulated in the occluded midgut, and were excreted in the meconium upon pupation.
用微孢子虫Vairimorpha necatrix（克雷默）感染甘蓝夜蛾（Lacanobia oleracea，林奈）幼虫，对茧蜂科寄生蜂回旋绒茧蜂（Meteorus gyrator，桑伯格）的存活和发育产生了显著影响。雌性回旋绒茧蜂在选择宿主产卵时，并未表现出对感染V. necatrix的宿主有任何回避行为。当寄生与病原体感染同时发生，或在感染后四天内发生时，未观察到对寄生蜂有显著的有害影响。然而，当寄生在感染后六至八天发生时，更大比例（12.5 - 14%）的宿主在寄生蜂幼虫羽化前死亡。成年黄蜂的成功羽化也减少了。当寄生和感染同时发生时，感染宿主中的寄生蜂幼虫发育明显更快，茧也明显更重。然而，随着感染和寄生之间的时间间隔增加，寄生蜂幼虫发育显著延长多达两天，形成的茧明显（约20%）更小。发育中的寄生蜂幼虫摄取了Vairimorpha necatrix孢子，这些孢子积聚在被阻塞的中肠中，并在化蛹时随蛹便排出。
