Male Reproductive System and Sperm Ultrastructure of the Yunnan Pine Shoot Beetle,Tomicus yunnanensis(Coleoptera:Curculionidae:Scolytinae)
[Objective]Insect reproduction is of vast significance in population processing for the growths and declines in natural or management habitats.Based on the theoretical and practical implications of pest population management,it is essential to gain the male reproductive system and sperm structure of Tomicus yunnanensis(Coleoptera:Curculionidae:Scolytinae),which are the most damaged insects in the Yunnan pine forest in southwest China.[Method]The male genital system and sperms from newly emerged adults(sexual immaturity)and the precocity of trunk-boring attacks(sexual maturity)of this spe-cies are examined structurally using light and transmission electron microscopy.[Result]The male genital system contains a pair of testes,two twins of tubular accessory glands,a couple of multilobulated access-ory glands and seminal vesicles,and deferent ducts connected with a single ejaculatory duct.After sexual immaturity,all genital cysts were only thin transparent tubules,which were milky and gradually thicker after sexual maturity.However,there was orange for the testes and multilobulated accessory glands.Mature sperms were numerous in seminal vesicles currently.Each sperm was filiform in shape,170.1±39.1 μm in length,and consisted of the head and flagellum.The head was needle-like,with 23.5±3.4 μm in length,and comprised a three-layer acrosomal complex and an inferior cylindrical nucleus.The long flagellum in-cluded two mitochondrial derivatives of different sizes,two accessory bodies with a sizeable puff-like ex-pansion,and a classical 9 + 9 + 2 axoneme microtubule pattern.More importantly,the sperm tail showd a high degree of differentiation in the shape of the asymmetrical organelles.Some tail organelles,including puff-like expansion,minor mitochondrial derivatives,accessory bodies,and major mitochondrial derivat-ives,would gradually disappear toward the end of the sperm.[Conclusion].The overall genital character-istics and sperm ultrastructure of the male adults of T.yunnanensis are like those of Curculionidae,which conserve the primitive characters such as three-layer acrosomal complex,9 + 9 + 2 axoneme and high dif-ferentiation of asymmetrical tail organelles.Current results not only enrich the taxonomic and phylogenetic studies of the subfamily Scolytinae,but also help us further understand the physiological attributes in in-semination specificity of Tomicus yunnanensis.
万方数据
维普
