微红梢斑螟生殖系统及卵巢发育特征研究

Study of the reproductive system and ovarian development of Dioryctria rubella Hampson

【目的】研究了微红梢斑螟Dioryctria rubella Hampson的生殖系统及不同发育阶段卵巢的形态结构，揭示交配过程中雌、雄外生殖器的匹配机制，为该虫生殖生物学及性信息素的研究提供依据。【方法】通过解剖及扫描电镜观察，描述内、外生殖器以及雌蛾卵巢发育特征。【结果】与其他斑螟亚科种类生殖系统比较，微红梢斑螟生殖系统主要具有以下形态特点：（1）微红梢斑螟雌蛾的交配囊片特别发达，导精管从交配囊体的侧腹面发出，导精管内无导精管球；（2）雌蛾腺体环状，位于第8-9腹节节间膜处，雄蛾具有发达的味刷构造，由6对重叠的鳞片刷组成；（3）雌蛾交配囊管表面的棘刺与雄蛾内阳茎外表面的阳茎针在分布位置和方向互补，具有高度匹配的关系。微红梢斑螟雌蛾卵巢发育进度可分为5级，2日龄后雌蛾卵巢饱满，发育良好；4日龄后卵巢衰退。【结论】（1）雄蛾发达的味刷及外生殖器的高度匹配关系提示其复杂的求偶行为和交配模式，加之成虫期较短，可能成虫为单次交配。（2）雌虫羽化后卵巢基本成熟，补充营养似乎并非卵巢发育的必要条件。

[Objectives] To investigate and describe the morphology of the reproductive system and ovarian development in Dioryctria rubella, and deduce the parts of the male and female genitals involved copulation based on their structural characteristics, with the goal of providing a basis for further study of the reproductive biology and sex pheromones of this insect. [Methods] The characteristics of the internal and external reproductive organs, and female ovarian development, were investigated by dissection and scanning electron microscopy. [Results] Compared with the reproductive systems of other Phycitinae species, distinctive structural characteristics of the reproductive system of D. rubella were as follows： （1） the corpus bursae possessed a well-developed signum, the seminal duct arises from the ventral surface of the corpus bursae, and no bulla seminalis was found. （2） The female sex pheromone gland was ring-like and situated in the intersegmental membrane between the 8th and 9th abdominal segments. Adult males possess well-developed scale brushes, which consist of six pairs of overlapped accessories. （3） The spines on the inner surface of the ductus bursae and the cervix bursa were complementary in position and direction, and a close match, to those of the coruuti on the outer surface of vesica. Furthermore, ovarian development could be divided into 5 stages; the ovaries of 2 day old females were well-developed but began to degenerate after females reached 4 days of age. [Conclusion] （1） The well-developed male scale brushes and highly matched genitals are indicative of complex courtship and mating behavior. The lifetime of adults is so short that they may only mate once. （2） Ovarian development is almost complete after female emergence, which indicates that post-emergence nutrition may not be a decisive factor in ovarian development.