| Neoseiulus californicus (Acari:Phytoseiidae), was found Institute of Plant Protection, Chinese Academy of Agricultural Sciences in china. Then it was identified as new record species in China. The preliminary experiment showed that N. californicus has higher capacity on predating western flower thrips which is an important invasive pest species. N.californicus has value of exploitation and utilization due to that it could be one of the potential biological control agents of western flower thrips. It is necessary to study its biology and experimental population ecology. Functional response, life table and predation preference are important measures of evaluation the potential biocontrol capability of N. californicus on Frankliniella occidentalis. In addition, as western flower thrips predators, whether it is efficiency in practical application in the field? How to decide the releasing ratio, release period and release position? So this thesis research content mainly includes the following aspects:1.The predation ability of four kinds of predatory mites(Neoseiulus californicus, Neoseiulus cucumeris, Neoseiulus barkeri and Amblyseius.orientalis) to newly hatched western flower thrips nymphs were studied under the condition that temperature25±1℃, RH70%±5%,L:D=16h:8h. The results showed that the functional response for adults of four kinds of predatory mites(N. californicus, N. cucumeris, N. barkeri and A. orientalis) could be described by the Holing II functional Response type, and could be expressed as Na=1.828N t/(1+0.243Nt), Na=1.988Nt/(1+0.205Nt),Na=2.008Nt/(1+0.309Nt), Na=0.998Nt/(1+0.158Nt),respectively. The attack rates and the handling time for N. californicus, N. cucumeris, N. barkeri and A. orientalis were1.828and0.133d,1.988and0.049d,2.008and0.154d,0.998and0.159d, respectively. The daily maximum predations are7.519for N. californicus,9.709for N. cucumeris,6.494for N. barkeri and6.289for A. orientalis, the control capability on western flower thrips newly hatched nymphs sorted in descending as N. cucumeris, N. californicus, N. barkeri and A. orientalis. We can draw a conclution that N. californicus have higher predation on western flower thrips nymph.2. The life table of the experimental population of N. californicus feeding on Frankliniella occidentalis nymph was established under the condition that temperature25±1℃, RH70%±5%, L:D=16h:8h. The results showed that the developmental duration of different stages of N. californicus were egg stage1.85d, larva stage0.76d, protonymph2.00d, deutonymph1.85d. The parameters of N. californicus are as follows, net reproductive rate(R0), mean generation time(T), intrinsic rate of increase(rm), finite rate of increase(λ), and doubling time(t) were19.10,19.26d,0.15,1.17and4.53d,respectively. Compares to the life table parameters of N. californicus and F. occidentalis, we conclude that intrinsic rate of increase of N. californicus was higher than F. occidentalis, It is indicate that native new record N. californicus has control potential for western flower thrips.3. The24h starved N. californicus have no preference between western flower thrips and Tetranychus cinnabarinus in the presence of their equal density(ie.10:10). It meant the predation is random, the preference index β1is0.40, during the experimental periods of12h, consuming2.87F. occidentalis and4.00T. cinnabarinus. When the density ratios of two kinds of prey were1:1～1:5, with the change of the density ratio, the predatory mite preference index is change. However, the predatory mite had also showed no preference.4. Releasing N. californicus on the eggplant plant in the greenhouse to study actual control efficiency of N. californicus for F. occidentalis. The experiment divided two biological control regions, and both set up three treatments, consisted of two releasing rates, N. calif ornicus:F. occidentalis was3:1or6:1, and CK. Every treatment designed with three replications. The first region release once predatory mites in June5th after statistics the western flower thrips population. The second region release twice predatory mites in June5th and June20th after statistics the western flower thrips population. The results showed that the whole control efficiency of N. californicus for F. occidentalis, the3:1and6:1treatment plot was58.93% and76.09% in the first region, and the3:1and6:1treatment plot was58.98% and74.08% in the second region. In addition,in the first biological control region, the control efficiency of3:1and6:1treatment plot for the different parts, upper, middle and lower position of plant, were35.09%、60.24%n、41.76%and70.91%、62.02%、70.22%, and in the second biological control region, the control efficiency of3:1and6:1treatment plot for the different parts, upper, middle and lower position of plant, were49.92%、70.71%、57.83%and69.11%、73.55%、73.22%. Releasing experiment indicate that releasing N. californicus has certain control efficiency for western flower thrips of Greenhouse Eggplant, and the control efficiency of the6:1treatment is better than3:1treatment, otherwise, the second region release has higher control efficiency than the first region, but no significant differences between the two releasing predatory mites regions. |
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