Pérez J, Rojas J C, Montoya P, Liedo P, Castillo A
Departamento de Entomología Tropical, El Colegio de la Frontera Sur-ECOSUR, Carretera Antiguo Aeropuerto Km 2.5, 30700 Tapachula, Chiapas, México.
Bull Entomol Res. 2013 Jun;103(3):318-25. doi: 10.1017/S0007485312000739. Epub 2012 Dec 7.
Fopius arisanus is a solitary egg-pupal endoparasitoid that attacks several species of tephritid fruit flies, particularly Bactrocera spp. This species, indigenous from the Indo-Australian region, was introduced into Mexico for biological control purposes. From the standpoint of the 'new associations' concept this parasitoid has been evaluated against fruit flies in the Anastrepha complex. We investigated the specificity of F. arisanus responses to fruits infested with two species of Anastrepha. We examined whether fruit volatiles attractive to this parasitoid are induced as a result of fruit fly oviposition. We also investigated whether F. arisanus females are able to discriminate between the oviposition-induced volatiles from host eggs parasitised by conspecifics and volatiles from unparasitised eggs. All experiments were performed in a wind tunnel. Results showed that mango fruits infested with A. ludens eggs (2-3 days after egg deposition) were significantly more attractive to naïve F. arisanus females compared with non-infested fruits or fruits infested with larvae. In addition, guava fruits harbouring A. striata eggs were significantly more attractive to the parasitoid than non-infested fruits or fruits infested with larvae. Thus, the parasitoid was attracted to fruits with eggs, but fruit and fly species did not influence the parasitoid attraction. We also found that F. arisanus females were more attracted to fruits exposed to fertile A. ludens females (i.e. fruits with eggs inside) compared with fruits exposed to sterile females (i.e. fruits with no eggs inside) or fruits with mechanical damage. Parasitoid females were not attracted to A. ludens eggs. The results suggest that the presence of eggs induces volatiles that attract parasitoids. Finally, we found that F. arisanus was able to discriminate between fruits with unparasitised eggs vs. eggs parasitised by conspecifics, indicating that host discrimination could be mediated by olfactory cues.
阿里山潜蝇茧蜂是一种独居的卵-蛹内寄生蜂，可寄生于多种实蝇科果蝇，尤其是果实蝇属的果蝇。该物种原产于印度-澳大利亚地区，为生物防治目的被引入墨西哥。从“新关联”概念的角度来看，已对该寄生蜂针对按实蝇复合体中的果蝇进行了评估。我们研究了阿里山潜蝇茧蜂对两种按实蝇侵染果实的反应特异性。我们研究了这种寄生蜂所吸引的果实挥发物是否是果蝇产卵的结果。我们还研究了阿里山潜蝇茧蜂雌蜂是否能够区分同种寄生的寄主卵的产卵诱导挥发物和未寄生卵的挥发物。所有实验均在风洞中进行。结果表明，与未侵染果实或幼虫侵染的果实相比，被拉美实蝇卵侵染的芒果果实（产卵后2-3天）对未接触过寄主的阿里山潜蝇茧蜂雌蜂具有显著更高的吸引力。此外，带有条纹实蝇卵的番石榴果实对该寄生蜂的吸引力明显高于未侵染果实或幼虫侵染的果实。因此，该寄生蜂被有卵的果实所吸引，但果实和果蝇种类并不影响寄生蜂的吸引力。我们还发现，与接触不育雌蝇的果实（即内部无卵的果实）或有机械损伤的果实相比，阿里山潜蝇茧蜂雌蜂对接触可育拉美实蝇雌蝇的果实（即内部有卵的果实）更具吸引力。寄生蜂雌蜂对拉美实蝇卵没有吸引力。结果表明，卵的存在会诱导吸引寄生蜂的挥发物。最后，我们发现阿里山潜蝇茧蜂能够区分未寄生卵的果实和同种寄生卵的果实，这表明寄主辨别可能由嗅觉线索介导。
