Onagbola Ebenezer O, Fadamiro Henry Y
Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA.
Micron. 2008 Jul;39(5):526-35. doi: 10.1016/j.micron.2007.08.001. Epub 2007 Aug 6.
Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae) is an ectoparasitoid of several insect pests of stored products. In order to provide requisite background information to support our ongoing research on its host location mechanisms, we examined the external morphology of the antennal sensilla of this parasitoid using scanning electron microscopy. Antennae of male and female P. cerealellae are geniculate in shape, approximately 1300mum in length, and consist of 15 antennomeres. Eight morphological sensilla types were recorded in both sexes, including four types of the highly abundant and widely distributed sensilla trichodea (types I, II and IV are aporous while type III is multiporous), basiconic capitate peg sensilla, coeloconic sensilla, chaetica sensilla, and the most conspicuous plate-like placoid sensilla. Detailed examination of sensilla morphological features including pore presence and numbers suggest that the multiporous type III sensilla trichodea and the multiporous placoid sensilla may play a role in olfaction, whereas the uniporous chaetica sensilla may function as contact chemoreceptors. The types I and II sensilla trichodea are presumably mechanosensory, while the type IV sensilla trichodea may function as proprioceptors. The basiconic capitate peg sensilla and coeloconic sensilla probably function in thermo-hygro reception. Although the shape, structure, and size of antennae of males and female were basically similar, major differences were recorded between the sexes in the distribution of some sensilla types. The type II sensilla trichodea and the multiporous placoid sensilla are relatively more abundant in females, whereas males have greater number of the multiporous type III sensilla trichodea than females. These results are discussed in relation to the possible roles of the sensilla types in the host location behavior of P. cerealellae.
麦蛾茧蜂（Ashmead）（膜翅目：茧蜂科）是几种储藏物害虫的体外寄生蜂。为了提供必要的背景信息以支持我们正在进行的关于其寄主定位机制的研究，我们使用扫描电子显微镜检查了这种寄生蜂触角感器的外部形态。麦蛾茧蜂雄蜂和雌蜂的触角呈膝状，长度约为1300微米，由15节触角组成。在两性中均记录到8种形态类型的感器，包括4种数量众多且分布广泛的毛形感器（I型、II型和IV型无孔，而III型多孔）、基部具头的栓状感器、腔锥感器、刺形感器以及最明显的板状鳞形感器。对感器形态特征（包括有无孔及孔的数量）的详细检查表明，多孔的III型毛形感器和多孔的鳞形感器可能在嗅觉中起作用，而单孔的刺形感器可能作为接触化学感受器发挥功能。I型和II型毛形感器大概是机械感受器，而IV型毛形感器可能作为本体感受器发挥功能。基部具头的栓状感器和腔锥感器可能在温湿度感受中起作用。尽管雄蜂和雌蜂触角的形状、结构和大小基本相似，但在某些感器类型的分布上两性之间存在显著差异。II型毛形感器和多孔的鳞形感器在雌蜂中相对更为丰富，而雄蜂的多孔III型毛形感器数量比雌蜂多。结合这些感器类型在麦蛾茧蜂寄主定位行为中可能发挥的作用对这些结果进行了讨论。
