甜菜夜蛾胚胎发育的研究(Ⅱ)——体腔、体壁、循环系统和部分器官的发育

Studies on the embryonic development of Spodoptera exigua (Hübner) (Ⅱ)——the development of coelom, integument, circulatory system and other organs

详细研究了甜菜夜蛾 Spodoptera exigua(Hübner)在胚胎发育中体腔、肌肉、体壁、循环系统、丝腺、脂肪体和绛色细胞的发育过程 ,并总结了 2 5℃下甜菜夜蛾胚胎发育的时间进度。体腔囊出现后 ,中胚层分为腹壁中胚层和背壁中胚层 ,前者将来形成体壁肌、脂肪体等 ,后者主要形成消化道外的肌肉层 ;腹壁中胚层与背壁中胚层交界处的细胞发育成成心细胞 ,随着背合的完成形成心脏 ,并与头部伸出的大动脉相接 ,形成背血管 ;胚胎发育到 5 0 h左右 ,体壁真皮细胞开始分泌含几丁质的表皮 ,幼虫孵化前 ,其体表布满脊突和刚毛 ;绛色细胞由胚体 1～ 8腹节的外胚层部分细胞发育而成。

This paper dealt with the formation of coelom, muscle, integument, circulatory system, silk gland, fat body and oenocytes during the embryonic development of Spodoptera exigua (Hübner), and summarized the developmental course at 25℃. The mesoderm differentiated into somatic mesoderm and splanchnic mesoderm after coelomic sals appeared, the former developing into musculus parietalis, fat body etc., and the latter forming muscles of the alimentary canal. Cardioblasts came out of cells between somatic and splanchnic mesoderm, then formed heart after dorsal enclosure and connected with the large artery to form the dorsal vessal. Epidermal cells began to secrete chitinous cuticle at 50th hour around. The embryo body was covered densely with crests and chaetae before hatching. Oenocytes derived from ectodermal cells of 1 to 8 abdomen.