温度对芒果小爪螨实验种群增长的影响

Effects of Temperatures on Development and Reproduction of Oligonychus mangiferus (Acari:Tetranychidae)

在16,20,24,28,32℃条件下观察芒果小爪螨的发育、存活及繁殖情况。结果表明:芒果小爪螨世代发育历期在32℃时最短,为9.20d,16℃时最长,为29.07d。卵、幼螨、若螨、产卵前期及世代的发育起点温度分别为8.77,9.37,10.61,11.13,8.91℃,有效积温分别为93.46,30.29,44.96,14.24,191.83日度,在16～32℃,芒果小爪螨发育的速率及雌螨寿命与温度呈直线相关。世代存活率在24℃时最高,为89.6%,32℃和16℃时,分别降至69.1%和55.8%。雌螨产卵量在28℃时最高,达40.14粒/雌,在32℃时最低,为8.44粒/雌。卵孵化率、幼螨、若螨及世代存活率、雌螨产卵量等随温度的上升而呈抛物线趋势。净增殖率(R0)、内禀增长率(rm)、周限增长率(λ)等种群特征参数以28℃时最高,分别为27.3342,0.3957,1.4854。平均世代历期和种群加倍时间分别以32℃和28℃时最短,分别为7.5186d,1.7517d。种群增长指数以24℃时最高,28℃时略低,分别为24.88和24.45。芒果小爪螨对温度较敏感,24～28℃为芒果小爪螨种群增长的最适温度。

Development,survivorship and reproduction of Oligonychus mangiferus reared on fresh mango leaves were evaluated at5constant temperatures(16,20,24,28,32℃).The results showed that the development time of a generation varied from9.20d at32℃to29.07d at16℃.The developmental thresholds for egg,larva,nymph,pre-oviposition and com bined immature stages were estimated at8.77,9.37,10.61,11.13,8.91℃,whereas their effective cumulative temperatures were93.46,30.29,44.96,14.24and191.83degree-days respectively.Under constant temperature conditions in the range of16~32℃,the development rate of the mites and the female longevity increased linearly with temperature,while the survivorships of the eggs,larvae,nymphs,whole generation and the fecundity of the adults increased with the tem peratures as parabola.Survivorship of a whole generation was the highest(89.6%)at24℃,whereas it came to69.1%and55.8%at32℃and16℃respectively.The highest number of eggs(40.14eggs per female)were recorded at28℃,the lowest number(8.44eggs per female)at32℃.Mites reared at28℃had the highest net reproductive rate(27.3342),intrinsic rate of increase(0.3957),and finite capacity of increase(1.4854).The shortest mean generation time (7.5186days)and pop ulation doubling time (1.7517days)were obtained at32℃and28℃respectively.The highest pop ulation trend index(24.88)was recorded at24℃,second(24.45)at28℃.It could be conclud ed that O.mangiferus was sensitive to temperature and24~28℃were the optimum tempera tures for the development and reproduction of the mite.