Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
J Insect Sci. 2012;12:49. doi: 10.1673/031.012.4901.
This study describes the molecular phylogeny, laboratory rearing, and karyotype of a bombycid moth, Trilocha varians (F. Walker) (Lepidoptera: Bombycidae), which feeds on leaves of Ficus spp. (Rosales: Moraceae). The larvae of this species were collected in Taipei city, Taiwan, and the Ryukyu Archipelago (Ishigaki and Okinawa Islands, Japan). Molecular phylogenetic analyses revealed that T. varians belongs to the subfamily Bombycinae, thus showing a close relationship to the domesticated silkworm Bombyx mori (L.), a lepidopteran model insect. A laboratory method was developed for rearing T. varians and the time required for development from the embryo to adult was determined. From oviposition to adult emergence, the developmental zero was 10.47 °C and total effective temperature was 531.2 day-degrees, i.e., approximately 30 days for one generation when reared at 28 °C. The haploid of T. varians consisted of n = 26 chromosomes. In highly polyploid somatic nuclei, females showed a large heterochromatin body, indicating that the sex chromosome system in T. varians is WZ/ZZ (female/male). The results of the present study should facilitate the utilization of T. varians as a reference species for B. mori, thereby leading to a greater understanding of the ecology and evolution of bombycid moths.
本研究描述了食榕属植物（桑科榕属）叶子的波丝野蚕（Trilocha varians）（鳞翅目：天蚕蛾科）的分子系统发育、实验室饲养和染色体组型。该物种的幼虫是在台湾台北市和琉球群岛（日本石垣岛和冲绳岛）采集的。分子系统发育分析表明，T. varians 属于天蚕蛾亚科，因此与家蚕 Bombyx mori（鳞翅目：蚕蛾科）关系密切，家蚕是一种鳞翅目模式昆虫。建立了 T. varians 的实验室饲养方法，并确定了从胚胎到成虫发育所需的时间。从产卵到成虫出现，发育零值为 10.47°C，总有效温度为 531.2 度日，即在 28°C 下饲养时，一代约为 30 天。T. varians 的单倍体由 n = 26 条染色体组成。在高度多倍体的体细胞核中，雌性表现出一个大的异染色质体，表明 T. varians 的性染色体系统是 WZ/ZZ（雌性/雄性）。本研究的结果应该有助于将 T. varians 作为 B. mori 的参考物种加以利用，从而更好地了解天蚕蛾科昆虫的生态学和进化。
