二斑叶螨与朱砂叶螨在棉花上的种间竞争力

Interspecies Competition between Tetraychus urticae Koch and T.cinnabarinus Boisduval Fed with Cotton

通过比较二斑叶螨(Tetraychus urticae Koch)和朱砂叶螨(T.cinnabarinus Boisduval)以棉花为寄主时,单种种群和混合种群数量动态及内禀增长力(rm)值来确定2种叶螨竞争力的大小。结果表明:2种叶螨试验单种种群的活动虫态数量动态曲线均在第38天达到峰值,两者的单种种群达到峰值时活动虫态数量基本相等;而在混合种群中,二斑叶螨和朱砂叶螨活动虫态数量达到峰值时分别是第48天和第54天,且达到峰值时,朱砂叶螨成螨数量约为二斑叶螨的2倍。无论单种种群还是混合种群,朱砂叶螨的活动虫态和成虫的rm均略高于二斑叶螨,表明在以棉花为寄主植物时,朱砂叶螨比二斑叶螨具有较强的竞争力。

Based on the comparing of population dynamics of single species and mixed population and the intrin- sic rate of increase （rm） when Tetraychus urticae Koch and T. cinnabarinus Boisduval fed with cotton, the inter- species competition were studied. The results showed that it was 38th day when the amounts of active mites and mature mites of T. urticae and T. cinnabarinus reach to peak in the single population ; and it is 48th and 54th day when the amounts of active mites and mature mites of T. urticae or T. cinnabarinus reach to peak in the mixed population, and the amounts of Tetraychus urticae Koch are 1 times higher than that of T. cinnabarinus Boisdu- val. Both in the single population and mixed population, the intrinsic rm of T. cinnabarinus active mites and ma- ture mites was higher than that of T. urticae, which suggested interspecies competition of T. cinnabarinus was higher than T. urticae fed on cotton.