| The predatory mite Androlaelaps casalis always bear into soft, humid, dark environment, such as soil, reserve substance, poultry feed and parasitise on body surface of small animals occasional. They crawl speedlly and fear of light, but very actively. Its prey consists of soil-inhabiting stages of many different organisms including pupae of thrips, larvae of sciarids, nematodes, Tyrophagusputrescentiae and so on. The biology of A.casalis fed on T. putrescentiae was investigated by laboratory experiment at different temperatures. The results are as follows:1. A.casalis had two modes of reproduction, gamogenesis and androgenetic parthenogenesis their offsprings were larvae (the majority) and egg. Adult female mites cannibalized adult male, larva and egg developmental stages. The interference also occurred among females.2. There was no significant difference of male’s development from the reproduction mode of parthenogenesis and gamogenesis. On the contrary, significant differences actually exsisted in the larvae development time from gamogenesis. The sex ration of the offsprings was0.26[(female)/(female+male)]. Adult female’s developmental stage (egg, larvae, protonymph, deutonymph)were1.70,0.96,3.25,3.5days at25℃3. Difference in the total number of offsprings per female actually existed in the two reproduction modes. In the parthenogenesis mode, the total number of offsprings per female were14, respectively, it were8.11in the gamogenesis mode. The maximal daily number of offsprings per female was0.8from parthenogenesis, which was higher than gamogenesis (0.5).4. The development time for juvenile male and female (larvae, protonymph, deutonymph) decreased with increasing temperature from19to27℃. Difference in juvenile development time between27℃and31℃were not significant, although the development time had a slight tendency to develop faster at31℃.5. The development time of female’s each stage in relation to the temperature was quadratic parabola. Each stage (larvae, protonymph, deutonymph) of female’s shortest development time was0.9,3.4,2.6, corresponding to the optimum temperature29.08,28.44,29.18in theory. For female’s larvae and protonymph, the temperature threshold for development were11.30℃and12.80℃, which was lower than male’s. Larvae of male and female had lowest effective accumulative temperatures, respectively,11.22degrees D. and12.27degrees D. 6. The highest daily number of offsprings per female at4temperature (19,23,27,31℃) was0.36,1.38,1.38,0.58, respectively, their total number of offsprings per female were5.36,13.15,14.39,4.91. Damographic parameters of net reproductive rate, intrinsic rate of increase, finite rate of increase were highest at27℃, respectively,3.59,0.05and1.05. The lowest doubling time was13.27d at27℃. |
PDF Full Text Request