菜粉蝶幼虫、蛹和成虫的雌雄形态鉴别

A simple method for distinguishing sex of Pieris rapae (L.) larva, pupa and adult

利用体视显微镜观察、测量、记录菜粉蝶不同虫态雌雄个体间的形态特征差异。雌雄菜粉蝶幼虫、蛹和成虫均存在显著的雌雄二型特征,3龄之后雄性幼虫的第6腹节有一对肾型黑斑,雌性幼虫无此斑。雄蛹第9腹节有生殖孔和一条短纵裂缝,裂缝两侧有凹凸不平的半圆形瘤状突起;雌蛹腹部第8、9腹节分别有生殖孔和产卵孔,且两孔之间亦有一条纵裂缝。雌蝶前翅背面有一对上下排列的黑圆斑,其腹部末端外生殖器为圆筒型;雄蝶前翅背面一对黑斑相对较小,颜色较浅,尤其下斑为浅灰色,腹部末端具钳状外生殖器。本研究揭示了菜粉蝶幼虫、蛹及成虫不同虫态的雌雄二型差异,比较研究并提出了便于快速鉴别雌雄个体的典型特征和识别方法。

Sexual dimorphism of different insect states of Pieris rapae were observed using microscope.Sexually dimorphic characteristics of larvae,pupae and adults were obvious.Male larvae after the 3 rd instar had a pair of renal black spots on the 6 th abdominal segment,which were absent in female larvae.The 9 th abdominal segment of male pupa had a genital pore and a short longitudinal crack,both sides of which have uneven semicircular tumor-like protrusions;The 8 th and 9 th abdominal segments of the female pupa had genital and oviposit pores,respectively,and a longitudinal crack connected the two pores.There was a pair of black round spots arranged up and down on the back of the female forewing,and abdominal terminal external genitalia was cylindrical.However,in adult males,the black spots were relatively small in size and light in color,especially the lower spot was light gray,the external genitalia was pincer-shaped.Sexually dimorphic features of different insect states of P.rapae can be rapidly and reliably sexed.