Orientation mechanisms and sensory organs involved in host location in a dipteran parasitoid larva
Orientation mechanisms and sensory organs involved in host location in a dipteran parasitoid larva
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DOI：
10.1016/j.jinsphys.2010.11.010
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发表时间：
2011-01-01
影响因子：
2.2
通讯作者：
Castelo, Marcela K.
中科院分区：
文献类型：
--
作者：
Crespo, Jose E.;Lazzari, Claudio R.;Castelo, Marcela K.
黑蝇（Mallophora ruficauda）是阿根廷潘帕斯地区养蜂的主要害虫之一。幼虫是三龄圣甲虫幼虫的独居外寄生类。红叶蛾的雌性不会在寄主上或寄主附近产卵，而是在高草上产卵。孵化后，幼虫被风吹散，落到地面上，在那里它们挖掘和寻找潜在的宿主。据了解，褐纹夜蛾二龄幼虫对其偏好的寄主即信号环头蝇三龄幼虫表现出积极的寻宿主行为。虽然寄主定位似乎是由化学线索介导的，但定向和感觉器官参与寄主定位的机制尚不清楚。为了解决这些问题，我们在实验室里进行了行为实验。我们还测试了定向行为是否完全基于化学线索的使用。结果表明，褐纹夜蛾幼虫在上颌触须上具有化学感受器。只有一个上颌触须足以定位，但他们的双侧消融消除了定位。此外，宿主体内的己烷提取物与活的宿主一样具有吸引力。我们的研究结果支持了褐纹夜蛾幼虫通过趋化趋化的方式在地下寻找寄主。(C) 2010 Elsevier Ltd.版权所有。
The robber fly Mallophora ruficauda is one of the principal pests of apiculture in the Pampas region of Argentina. Larvae are solitary ectoparasitoids of third-instar scarab beetle larvae. Females of M. ruficauda do not lay eggs on or near the hosts, but on tall grasses. After hatching, larvae are dispersed by the wind and drop to the ground, where they dig and search for potential hosts. It is known that second-instar larvae of M. ruficauda exhibit active host-searching behaviour towards their preferred hosts, i.e., third-instar larvae of Cyclocephala signaticollis. Although host-location seems to be mediated by chemical cues, the mechanism of orientation and the sensory organs involved in host location remain unknown. We carried out behavioural experiments in the laboratory to address these questions. We also tested whether the orientation behaviour is exclusively based on the use of chemical cues. We found that larvae of M. ruficauda detect the chemicals with chemosensilla on the maxillary palps. Only one maxillary palp suffices for orientation, but their bilateral ablation abolishes orientation. Besides, an hexane extract of the host body was as attractive as a live host. Our results support that M. ruficauda larvae find their hosts underground by means of chemoklinotaxis. (C) 2010 Elsevier Ltd. All rights reserved.