红脂大小蠹成虫触角感器的扫描电镜观察

红脂大小蠹Dendroctonus valens LeConte属鞘翅目Coleoptera小蠹科Scolytidae,是我国一种重要的外来入侵害虫。为探究其寄主找寻、配偶找寻和种群聚集等行为机制,本文利用扫描电镜技术,对红脂大小蠹雌雄成虫的触角进行了观察,并对感器进行了分类以及其分布规律的研究。结果表明:红脂大小蠹雌雄成虫触角上共存在包括刺形感器、毛形感器、锥形感器、腔锥形感器和Bhm氏鬃毛在内的5种感器类型,其中毛形感器又分为形态各异的3种亚型。这些感器类型大都在触角的棒节上成带状分布。通过对比其他类似的研究以及感器的外部形态特征,推测红脂大小蠹的毛形感器和锥形感器是化学感受器,是最重要的嗅觉器官;刺形感器、腔锥形感器以及Bhm氏鬃毛是机械感受器,且腔锥形感器可以感受温湿度,Bhm氏鬃毛可以感知触角的位置。研究结果为明确红脂大小蠹的生境选择、种群聚集等行为机制提供了理论基础。

Antennal sensilla of the red turpentine beetle Dendroctonus valens LeConte (Coleoptera: Scolytidae)

The red turpentine beetle Dendroctonus valens LeConte (Coleoptera:Scolytidae) is one of the most important invasive alien species in China.To reveal the host-finding,mating and gathering mechanisms,antenna1 sensilla of this species were identified,and sensillum distribution pattern was analyzed using scanning electron microscope.Five types of sensilla were found on both male and female antennae,including sensilla chaetica,sensilla trichodea (subtype 1-3),sensilla basiconica,sensilla coeloconica,and Bohm's bristles.The majority of these sensillum types or subtypes was lined in rows on the club segment,the rest of which was located on the funicle and basal segments of antennae.Based on the morphological characters and distribution pattern of these sensilla along with similar researches concerning sensillum functions,it was concluded that sensilla trichodea and sensilla basiconica were major olfactory organs;sensilla chaetica,sensilla coeloconica and Bohm's bristles were mechanical detectors,possibly reacting to direct touch,vibrations or change of humidity.The results formed a fundamental basis for further researches regarding the habitat selection and gathering mechanisms.