竹裂爪螨毛竹种群与慈竹种群对不同寄主植物的适应性及其生殖隔离

对危害毛竹(Phyllostachys pubescens)和慈竹(Neosinocalamus affinis)的竹裂爪螨(Schizotetranychus bambusae)两个种群进行相互间的食性选择和生殖隔离试验．结果表明，由于两种竹子叶片在物理结构上差异较大。尤其是慈竹叶片背面具有成排细茸毛，导致竹裂爪螨毛竹种群不能在慈竹叶上完成世代发育；竹裂爪螨慈竹种群能取食，危害毛竹叶片，但由于寄主转换后，对其生长发育不利，导致存活率低，繁殖力弱．两种群取食各自嗜食的寄主植物时，基本生物学特性存在差异，27℃条件下，当毛竹种群以毛竹为食时，种群的内禀增长率(rm)、周限增长率(λ)、净增殖率(Ro)分别为0．1415、1．1520和15．6298；慈竹种群以慈竹为食时，rm、λ、Ro分别为0．0993、1．1044、10．0622；慈竹种群取食毛竹叶片时，rm、λ、Ro分别为0．0391、1．0399和2．5542．生殖隔离试验表明，两种群间能互相正常交配，且互相交配的时间与两种群自交时的交配时间(1次)差异不明显．同一种群交配产生的后代，其性比均在2：1左右，而不同种群杂交产生的后代全部为雄性(竹裂爪螨为孤雌产雄)，这表明两种群在长期的寄主植物选择压力下已形成一定的生殖隔现象．

Host plant suitability and reproductive isolation of two Schizotetranychus bambusae populations from the bam-boo species Phyllostachys pubescens and Neosinocalamus affini

Development, survivorship, reproduction and procreation isolation of Schizotetranychus bambusae from the bamboo species Phyllostachys pubescens and Neosinocalamus affinis reared on different host plants were evaluated in laboratory. The results showed that the population of S. bambusae from Phyllostachys pubescens (PhS) failed to complete its life cycle when reared on the leaf of N. affinis. When the population of S. bambusae from N. affinis (NeS) was reared on the leaf of P. pubescens, the survivorship and fecundity decreased. The rm, lambda and Ro were 0.0391, 1.0399 and 2.5542, respectively. At 27 degrees C, when the PhS was reared on P. pubescens, rm, lambda and Ro were 0.1415, 1.1520, and 15.6298, respectively, whereas NeS was reared on N. affinis, rm, lambda, and Ro were 0.0993, 1.1044, and 10.0622, respectively. Reciprocal cross test between PhS and NeS showed tht the two populations could mate, but laid unfertilized eggs that produced male only, indicating the existence of reproductive isolation.