Studies On The Population Ecology Of Tyrophagus Putrescentiae (Schrank) (Acari: Acaridae)

Tyrophagus putrescentiae (Schrank) is a storage mite that has a worldwide distribution. This paper studies systematically on population ecology of T. putrescentiae. The major results were as follows:1. Effect of temperature on development of T. putrescentiae: The duration among all immature stages were shortened with increasing temperature. Between 16℃and 32℃, development time was 55.37days at 16℃and 11.46days at 32℃. The analysis suggested that the relationship between development and temperatures were fit for logistic equation model. And the developmental threshold temperature and effective temperature summation of different developmentat stages were worked out by the linear regression equation and Lidian-mo's optional methods. And we saw that Lidian-mo's optional methods is better than the linear regression equation.2. The experimental population life tables of T. putrescentiae: The maximum longevity was 62.92 days at 16℃, and the maximum total eggs per female were 87.69 at 28℃. The experimental population life tables of T. putrescentiae were constructed at 16℃, 20℃, 24℃, 28℃, 32℃. The results showed that the net reproductive rate reached the highest values of 88.414 at 28℃, and the intrinsic rate of natural increase (r_m) and finite rate of increase (λ) increased with temperature to a peak of 0.194, 1.214 at 28℃. The time for population to double was shortest of 3.573 days at 28℃. However, the sex ratio was increased with increasing temperatures.3. The influence of higher temperature(37℃-49℃) on different stages of T. putrescentiae: At 49℃it taked 21min to kill all the adults, 18min to all the tonymphs and 15min to all the larva, but it taked 12h to kill all the adults, 9h to kill all the tonymphs and 6h to kill all the larva at 39℃. At 37℃, it could continue growth.4. The predation of Cheletomorpha lepidopterorum to T. putrescentiae: At six constant temperatures, all the functional response of Cheletomorpha lepidopterorum on T. putrescentiae exhibited Holling's Type-Ⅱfunctional response. Among all stages and temperatures, adult female was the most efficient predatory stage at 28℃. The adult female Cheletomorpha lepidopterorum was the more efficient predatory stage, followed by the adualt male. The predator's density affected its preying ratio and the preying ratio decreased with the increasing predator's density.