寄主型和迁飞型棉蚜的交配行为

棉蚜Aphis gossypii Glover种群存在寄主利用和迁飞能力上的明显分化,有棉花型和瓜型、迁飞型和滞留型之分。但是,棉花型与瓜型之间,以及迁飞型与滞留型之间是否能发生交配行为,尚无研究报道。本文在低温和短光照条件下分别诱导棉花型、瓜型、迁飞型和滞留型棉蚜的性蚜,并进行性蚜间的交配行为观察。结果表明,迁飞型和滞留型性蚜间可以发生交配行为,杂交时发生交配行为的个体比率与自交时无显著差异,但是杂交时雄蚜寻找配偶所花的时间要显著长于自交时,并且迁飞型雌蚜(M♀)与滞留型雄蚜(S♂)杂交时的交配持续时间也显著长于自交时。迁飞型和滞留型棉蚜同型交配容易完成,棉蚜的迁飞型和滞留型已在交配行为上产生了一定的分化。棉花型和瓜型棉蚜的性蚜间可以发生交配行为,并且两品系在正交和反交时雄蚜的寻偶时间与交配持续时间均无显著差异。

Mating behaviour of host-specialized and migratory biotypes of the cotton aphid

Variation in host use and flight ability in the cotton aphid Aphis gossypii Glover is such that some biotypes can be regarded as cotton-specialized, cucurbits-specialized, migratory and sedentary. However, it is not known whether cotton-specialized and cucurbits-specialized biotypes, or migratory （M） and sedentary （S） biotypes, interbreed. The sexual forms of cotton-specialized, cucurbits-specialized, migratory, and sedentary biotypes were induced under reduced temperature and short photoperiod and their mating behavior was investigated. The results indicate that migratory and sedentary biotypes interbred, and the number of males that completed copulation within three hours did not significantly differ between inter-biotype and intra-biotype mating. However, it took significantly longer for males to find a mate of another biotype than one of their own biotype. The duration of copulation of M ♀ × S ♂ was also significantly longer than that of M ♀ × M ♂ and S ♀ × M ♂ . Mating was more likely to occur when the male and female were of the same biotype than when they were from different biotypes. There was a trend towards assortative mating between migratory and sedentary biotypes. Interbreeding occurred between cotton-specialized （Co） and cucurbits-specialized （Cu） biotypes, and the time required for males to find a mate and complete copulation were similar between Co ♀ ×Cu♂ cross and Cu ♀ × Co♂ cross.