Study Of Experimental Population Ecology Of Amblyseius Barkeri(HugHes)

Amblyseius barkeri is an common natural enemy in citrus orchard and it plays an important role in control of Panonychus citri McGregor.The basic biological characteristics,reproduction and development of A.barkeri reared on Aleuroglyphus ovatus(Troupeau),were studied on the different temperature.the predatory function of A.barkeri to Panonychus citri(McGregor),and toxicity comparision on pyridaben to A.barkeri and Tetranychus cinnabarinus(Boisduval).For the future in-depth study of mites,the use of a large number of breeding and release provides a theoretical basis. Main contents and conclusions are as follows:1.Basic biological research of Amblyseius barkeri(HugHes)Amblyseius barkeri(HugHes) is a wide range of pest mites,thrips and other insects important predators.Experienced the process of egg,larva,nympha,adult into four developmental stages.They produce mainly by amphigenesis,there is a preoviposition period from mating to oviposition,egg are laid sparsely.Feeding on Tyrophagus putrescentiae(Schrank) and Aleuroglyphus ovatus(Troupeau),Amblyseius barkeri (HugHes) generations be able to complete a cycle.2 Development of different temperatures on the reproduction of A.barkeri2.1 Relationship of developmental rate and temperatureThe development of Amblyseius barkeri(HugHes) at different constant temperatures was investigated.The results showed that the developmental duration of A.barkeri was shortened gradually with the increasing of temperature at the temperature range of 16-28℃,and the developmental durations for egg,larva,and whole generation varied from 3.34 to 1.38 d,1.65 to 0.65 d,and 5.53 to 14.99 d,respectively.However,at 30℃and 35℃,the developmental duration was prolonged for all life stages.The developmental duration of egg and pre-oviposition stages were linearly correlated with temperatures. while the relationship between the developmental duration of other stages and temperatures were a parabola opening upwards.According to the priority law,the developmental threshold of pre-oviposition period was 12.11℃,and all other various stages and whole generation were lower,6.87℃(generation) and 8.03℃(larva),with an effective thermal sum of 137.58℃for generation.Based on the model of Wang Rusong,the optimum developmental temperature for the mite was 28-30℃.critical lethal high temperature was 35.31℃-38.94℃,and critical lethal low temperature was 7.23℃-8.74℃.2.2 Experimental population life table of Amblyseius barkeri(HugHes)experimental population life table of A.barkeri,with A.ovatus as its prey,were constructed at 16℃,20℃,25℃,28℃,30℃,35℃.The results showed that the net reproductive rate(Ro),Intrinsic growth(rm) and finite rate of increase(λ) of A.barkeri. At 28℃reached the highted values of 9.0697 the net reproductive rate(Ro),at 25℃reached 4.9262.At 28℃reached the highted values of Intrinsic growth(rm) and finite rate of increase(λ) were 0.1295,1.1383 respectively.The three parameters increased as the temperature decreased at 28℃.At 28℃the time for population to double(t) was shortest,4.4150 days,at 30℃was 5.3525 days.At 25℃,the average generation time was most,14.3810,at 35℃was 8.5445.3.The predacious function of Amblyseius barkeri(HugHes)Under 25℃,60-80%RH,studied functional response of A.barkeri feeding Panonychus citri(McGregor) different stages.The result showed that the functional responses of A.barkeri feeding P.citri different stages were fit for the cure of Holling TypeⅡ.The highest daily predation of A.barkeri to larva and nympha of P.citri was 6.25±0.59,egg was 3.00±1.34,adult was 2.23±0.60.4.Toxicity comparision on pyridaben to A.barkeri and Tetranychus cinnabarinus (Boisduval)Under 25℃,60-80%RH,15 percent will pyridaden configured with water concentration of 5-7,FAO recommended the use of slide dip method.Toxicity determination of A.barkeri and Tetranychus cinnabarinus(Boisduval).When changes in two types of mite mortality rate of the same,A.barkeri far greater than the dose of the dose T.cinnabarinus changes,from the change of LD50-LD99.LD90,LD95 and LD99 of A.barkeri were 11.75times,23.63times,87.58 times for LD50,respectively.T. cinnabarinus.LD90,LD95 and LD99 of T.cinnabarinus were 2.17times,2.70times, 4.08times for LD50.Pyridaben populations killed 90%,95%and 99%of the individual when A.barkeri dose required T.cinnabarinus than the much higher.