稻虱跗扇的个体发生研究：卵的形成和胚胎发育

捻翅目昆虫是胎生的，胚胎发育和孵化均在母体血腔内进行。稻虱跗Ｅｌｅｎｃｈｉｎｕｓ　ｊａｐｏｎｉｃｕｓ属捻翅目，跗科，寄生于白背稻虱、褐稻虱和灰稻虱。本文报道稻虱跗　卵的形成各阶段：１）雌虫体内无典型的卵巢，所有卵在母体体腔内同步发育和成熟。最早发现的原卵是包囊干细胞，在雌幼虫血腔内。２）每个包囊细胞内含２５６个姐妹细胞，其中有一个细胞分化成卵母细胞，其余的成为营养细胞。３）成熟卵为椭圆形，大小为７５－１００×４０－５０μｍ。其胚胎发育过程按顺序包括：卵裂、胎盘形成、胚带分节、附肢形成和胚胎背合等阶段。稻虱跗　行单胚生殖。

STUDIES ON THE ON ONTOGENY OF ELENCHINUSJAPONICUS (ELENCHIDAE: STREP SIPTERA ): EGGFORMATION AND EMBRYONIC DEVELOPMENT

trepsiptera are very specialized insects which carry out a unique type of vivipar-ity with egg formation and embryonic development taking place within haemocoelof the female. Elenchinus japonicus belongs to Elenchidae, Strepsiptera, and parasi-tizes the planthoppers Sogatella furcifera, Nilaparvata lugens and Laodelphax stri-atellus. In this work the stages of egg formation and embryonic development in S.furcifera were carefully observed microscopically. The female insect lacks typicalovaries; the eggs develop and mature synchronically within the adipose tissue nearthe body wall. At the beginning, the primary oocytes are derived from the cystobl-asts each of which consists of 256 sibling cells. One of these cells differentiatesinto the oocyte and the rest become the nurse cells. The mature egg is ellipticaland measures 75-100 x 40-50 um. It undergoes cleavage, blastoderm formation,segmentation of germ band, formation of appendages and dorsal enclosure to formthe mature embryo monoembryonically.