Inter- and intra-specific host discrimination in gregarious and solitary endoparasitoid wasps
Inter- and intra-specific host discrimination in gregarious and solitary endoparasitoid wasps
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DOI：
10.1007/s10526-013-9532-0
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发表时间：
2013-07
期刊：
影响因子：
2.5
通讯作者：
P. Magdaraog;Toshiharu Tanaka;J. Harvey
中科院分区：
文献类型：
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作者：
P. Magdaraog;Toshiharu Tanaka;J. Harvey
在自然界中，鳞翅目的大部分物种都受到拟寄虫的攻击，有些物种可能是几种拟寄虫的宿主。当寄主被同一物种的多个雌性寄生（=超寄生）或不同物种的雌性寄生（=多重寄生）时，就会发生对寄主资源控制的内在竞争。为了减少竞争，一些寄生蜂能够识别被寄生和未被寄生的寄主之间的区别。研究了两种同域种，即群居的cotesia kariyai（Watanabe）和独居的meteorus pulchricornis(Wesmael)，东方粘虫mythimna separata（Walker）的内寄生虫的种间和种内寄主歧视。为了测量寄主歧视，我们进行了选择实验，让两种物种的雌性觅食并在健康的寄主幼虫和最初被其中一种寄生的寄主之间进行选择。kariyaiorM。pulchricornis。用嗅觉试验研究了两种寄生蜂的辨别行为。结果表明，在产卵选择试验中，这两种小蜂都能区分未被寄生的寄主和被同种和异种寄生蜂攻击过的4 ~ 7天的寄主。另一方面，早寄生2天的寄主幼虫也存在超寄生和多重寄生现象。然而，一旦未成熟的拟寄主处于幼虫期（1龄和2龄），在双选项实验中避免了超寄生和多重寄生，而后者在多项选择实验中经常发生。寄主的识别能力可能是基于受损植物产生的植物挥发性信号和4 ~ 7个被寄生后寄主的内部机制。
In nature, most species of Lepidoptera are attacked by parasitoids, and some species may be hosts for several parasitoid species. When hosts are parasitized by more than one female of the same species (=superparasitism) or females of different species (=multiparasitism), then intrinsic competition occurs for control of host resources. To reduce competition, some parasitoids are able to recognize the difference between parasitized and unparasitized hosts. Inter- and intra-specific host discrimination were investigated in the two sympatric species, the gregariousCotesia kariyai(Watanabe) and solitaryMeteorus pulchricornis(Wesmael), endoparasitoids of the Oriental armywormMythimna separata(Walker). To measure host discrimination, choice experiments were conducted in which females of both species foraged and chose between healthy host larvae and hosts initially parasitized by eitherC. kariyaiorM. pulchricornis. An olfactory test was also performed to examine the discrimination behavior of the two parasitoids. Our results showed that, in oviposition choice tests, both braconid female wasps were able to discriminate between unparasitized hosts and from four to seven day-old hosts previously attacked by conspecific and heterospecific wasps. On the other hand, superparasitism and multiparasitism occurred even in host larvae that were parasitized two days earlier. However, once the immature parasitoids hosts are at larval stage (1st and 2nd instar), super- and multiparasitism were avoided in the two-choice test, but the latter often occurred in the multiple-choice experiment. Host discrimination abilities may have been based on plant volatile signals incurred from damaged plants and internal mechanisms from four to seven post-parasitized hosts.