Host-parasitoid interactions relating to penetration of the whitefly, Bemisia tabaci, by the parasitoid wasp, Eretmocerus mundus
Host-parasitoid interactions relating to penetration of the whitefly, Bemisia tabaci, by the parasitoid wasp, Eretmocerus mundus
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DOI：
10.1673/1536-2442(2005)5
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发表时间：
2005-12
影响因子：
2.2
通讯作者：
D. Gelman;D. Gerling;M. Blackburn
中科院分区：
文献类型：
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作者：
D. Gelman;D. Gerling;M. Blackburn
摘要据报道，烟粉虱蚜小蜂Eertmocerusmundus寄生甘薯粉虱Bemisiatabaci（B型）的所有4龄若虫，其中3龄是首选寄主。寄生蜂将卵产在寄主若虫下面的叶子上。第一龄孵化，后来穿透粉虱。以往的研究表明，寄生蜂侵入的起始诱导宿主在寄生蜂周围形成细胞囊。如本文所述，一旦4龄粉虱若虫开始成虫发育，雌性就不再产卵。一龄E.在2、3和4龄粉虱幼虫下观察到mundus幼虫，然而，直到粉虱达到4龄才发生穿透。非穿透性E. Mundus幼虫几乎总是在其4龄粉虱宿主中引起永久性发育停滞，并且还引起全身宿主蜕皮类固醇滴度的降低。因此，除非有一个峰值蜕皮激素滴度在当地的渗透，它似乎是胶囊形成的诱导是由于蜕皮激素滴度的增加。随着被膜的形成，寄主表皮细胞不断增殖，逐渐变成立方形和柱状，在被膜的发育过程中，特别是在被膜的腹侧开口处，形成了较厚的角质层。新形成的寄主角质层在蒴果的背侧部分较薄，在其顶端似乎没有。这些结果提供了新的信息有关的寄生虫产卵和卵孵化的时间和动态幼虫穿透，寄生虫引起的粉虱发育，蜕皮激素滴度和胶囊形成的过程中的变化。
Abstract It has been reported that the aphelinid wasp Eertmocerus mundus parasitizes all four nymphal instars of the sweet potato whitefly, Bemisia tabaci (Biotype B), with 3rd instars being the preferred hosts. The parasitoid lays its egg on the leaf underneath the host nymph. First instars hatch and later penetrate the whitefly. Previous studies have shown that the initiation of parasitoid penetration induces the host to form a cellular capsule around the parasitoid. As described here, females never oviposited once the 4th instar whitefly nymph had initiated adult development. First instar E. mundus larvae were observed under 2nd, 3rd and 4th instar whitefly nymphs, however, penetration did not occur until the whitefly had reached the 4th instar. The non-penetrating E. mundus larva almost always induced permanent developmental arrest in its 4th instar whitefly host and also caused a reduction in whole body host ecdysteroid titers. Therefore, unless there is a peak in molting hormone titer in the area local to penetration, it appears that the induction of capsule formation is not due to an increase in ecdysteroid titer. As the capsule formed around the penetrating parasitoid, host epidermal cells multiplied and became cuboidal and columnar, and relatively thick layers of new cuticle were deposited within the developing capsule, particularly near its ventral opening. The newly formed host cuticle was thinner in the dorsal part of the capsule and appeared to be absent at its apex. These results provide new information regarding the timing and dynamics of parasitoid oviposition and egg hatch as related to larval penetration, parasitoid-induced changes in whitefly development, molting hormone titers and the process of capsule formation.