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

Heavy metal is a kind of biological hazards heavier environmental pollutants, there are many studies reports about the harm of heavy metal to plants and animals, but the reports about heavy metal effects on mite growth and reproductive behavior is less. In order to further understand the impact of heavy metals on the growth and reproduction of crop production region of the mite, In the experiment use Tyrophagus putrescentiae as the experimental mite source, set up four groups of different concentrations of heavy metal lead to corrosion T. putrescentiae. Study the growth and development of different lead concentrations after feeding on different heavy metals; Under different concentrations of lead stress corrosion of T. putrescentiae reproductive ability; Lasioseius sp. Prey on feeding the different lead concentrations of T. putrescentiae. Results the points mentioned below:1. Effect of different concentration of Pb on the developmental durantions of T. putrescentiae : The developmental period of T. putrescentiae was increased with the concentration of Pb increased. Under five different concertration of Pb(0, 0.2, 2, 6, and 12mg/kg), the whole development duration was the longest(16.06d)under the highest level of Pb, and it was the shortest(14.64d) under zero level of Pb. Stress on Pb could depress the developmental rate of T. putrescentiae.2. The experimental population life tables of T. putrescentiae : The experimental population life tables of T. putrescentiae under four different concentration(0.2, 2, 6 and 12 mg/kg, respectively) of Pb were established. The amount of eggs of T. putrescentiae under the lowest 0.2 mg/kg Pb is the most. And itsnet reproductive rate(R0), mean generation time(T) and the intrinsic growth rate(rm), finite rate of increase(?) are 70.6935, 27.4181, 0.15531 and 1.16802, respectively.Therefore, the population doubling time(DT), is the shortest(4.4629 d). With Pb concentration increasing, life table parameters of T. putrescentiae were decreased. In contrast to all of level Pb, amount of eggs, R0, T, rm and ? were the lowest under the highest concentration of Pb. The results indicated that Pb stress could reduce the reproduction and weaken population increasing ability of T. putrescentiae.3. The predation of Lasioseius sp. To T. putrescentiae: Predatory functional response of Lasioseius sp. to T. putrescentiae fed on five different Pb concentrations was in accordance with Holling II equation.With Pb concentration of artificial diet increasing, predating quantity of Lasioseius sp. to T. putrescentiae was increased Andpredation ability of Lasioseius sp. to the nymph of T. putrescentiae is higher than to its adults.