Studies On The Experimental Population Ecology And Control Of Tetranychus Urticae Koch On Rose

The thesis studies on Tetranychus urticae Koch on Rose in Guangzhou as the research object,explore the impact of temperature to T.urticae growth and development,fecundity,high temperature tolerance,predation of natural enemies to T.urticae,five acaricide for T.urticae on Rose virulence.1.Effect of temperature on development of T.urticae:Within the temperature range from 20 ? to 36 ? were significantly affected by different temperatures.The developmental period was negatively correlated with the temperature.The development duration of different immature stages decreased with the increasing temperature;the total developmental duration from egg to adult varied from 8.49 to 20.45 days.Temperature had a significant effect on the development of T.urticae the lower thermal threshold for development and the thermal constant from egg to adult were 10.43 ? and 218.29 degree-days.The Logistic model accurately described the effect of temperature on developmental rate of T.urticae.2.Effect of temperature on fecundity of T.urticae:Within the temperature range from 20 ? to 36 ? were significantly affected by different temperatures.The highest eggs laid per female was at 28 ?,while the least was at 36 ?;the intrinsic rate of increase was 0.277 at 36 ?;maximum of R0 was 49.977at 32 ?.female offspring was the least at 20 ?,maximum at 36 ?.The temperature has great influence on the offspring sex ratio.3.Studies on the resistance of T.urticae:Under 85%RH humidity conditions with 40?,42 ?,44 ?,46 ?,48 ?,50 ? constant higher temperature treatment of T.urticae larva's L time 50 are 36.022 h,26.818 h,11.594 h,7.968 h,2.465 h,1.337 h;the nymph's L time 50 are 40.700 h,28.336 h,18.972 h,11.179 h,2.706 h,1.417 h;the female's L time 50 are 44.649 h,34.839 h,20.820 h,13.843 h,3.051 h,2.083 h.The constant higher temperature treatment of T.urticae results show that:female>nymph>larva.4.The control effect of natural enemies on T.urticae:Different temperature of Amblyseius cucumeris.Neoseiulus barkeri?Scolothrips takahashii predatory T.urticae on each states comply Holling? functional response model.In the density range,as the density is increased T.urticae on each states,they are also increasing the amount of prey.At the same prey densities,the daily predation of them predatory egg maximum is at 28 0C:10.638?11.111?24.390,the minimum is 16?:7.692,8.621,17.857;the daily predation of them predatory larva maximum is at 28 ?:10.000,22.222,21.739,the minimum is 16 ?:7.194,11.111,17.857;the daily predation of them predatory nymph maximum is at 28 ?:10.101,10.753,20.000,the minimum is 16 ?:11.111,8.772,16.393;the daily predation of them predatory female maximum is at 28 ?:6.579,8.621,17.85,the minimum is 16 ?:3.236,5.025,11.494.The predation of S.takahashii is the strongest,followed by N.barkeri,A.cucumeris worst.5.Control of acaricide to T.urticae:Five common acaricide for T.urticae virulence in the order:Chlorfenapyr>Cyflumetofen>avermectin>amitraz>BIFENAZATE.In the T.urticae Rose field control experiment,the best control effect is BIFENAZATE,was 100%;followed by Cyflumetofen,was 99.79%;avermectin control effect worst,only 88.02%.