| Neoseiulus californicus (McGregor) is the important enemy of Panonychus citri, Tetranychus cinnabarinus (Boisduval), Panonychus ulmi, T. urticae, T. truncates and etc. The article researched the morphology and identify the order of the ribosome ITS of T.ludeni, one of the spider mite on the kiwi fruits, and researched the effect of temperature on the growing development and reproduction, and the predation of Neoseiulus californicus.The main research results are as follows:1. Identification of tetranychid mite on kiwi fruitThe 4 species of mites on kiwi fruit collected from Shuangliu County in Chengdu City, Sichuan Province were analyzed by morphological, and analyzed the ITS sequence of one unknown species (Tetranychus sp.) of those mites. The results of morphological identification showed that there are three mites on kiwi fruit:Tetranychus. cinnabar inus(Boisduval), Tetranychus urticae, Eotetranychus kankitus Ehara. The unknown female mite species were oval, red, yellow green of in front of two pairs of legs.There are 12 hair on the back, and 2 of anus,lack of breeching.Male is yellow green,and slightly rhomboid.The proximal processes of preputial hammer is short, and sharp rear of the end. The rear shield without processes. Combined with the results of ITS2 PCR amplification,and sequencing,it can determine that the unknown mite is Tetranychus ludeni.2. Effect of temperature on the growing development and reproduction of T. ludeniUnder the temperature gradient of 19,22,25,28,31℃,with temperature increasing, the development duration, the life of female mite, and oviposition period of T. ludeni gradually shortened; average daily fecundity increased; the total oviposition increased at first and then decreased with temperature changed, at 28℃ maximum of 114.5 eggs. Average daily oviposition are 2.61 eggs that is the lowest at 19℃, the total are lowest with 60.25 eggs at 31℃.Under the same temperature, the shortest developmental duration is the first nymphs,and the longest is the egg period. Under the temperature gradient of 19,22,25,28,31℃,the development period of protonymph are 3.00,2.75,2.00,1.60,1.08d; and the deutonymph are 7.23,6.17,4.83,3.58,2.77d. All stages development period are 20.24d, 18.36d,12.83d,10.88d,8.54d. Use Logitic model and linear model matching the relationship between development rates and temperature. The results showed that the Logistic model can better describe the relationship between the two changes.The development zero and effective accumulative temperature of all generation are 13℃ and 200d-℃.3. The predation effect of Neoseiulus californicus to T. ludeniResearched the functional response of Neoseiulus californicus female adult on the egg,larva, nymphs,three stages of T. ludeni, as a result,they all have a good matching to Holling II disk equation. In 5,10,15,20,25,30 (grain) prey density range, with the increasing of density of every stage of mite, the predation amount of Neoseiulus californicus increased. Compared and analyzed the parameter of functional response a, Th, 1/Th(Namax), a/Th, it was showed that the control ability a/Th of Neoseiulus californicus to T. ludeni is larva >egg> nymphs.Neoseiulus californicus female adult has searching effect on egg, larva, nymphs, three stages of T. ludeni, it will decrease with the increasing of all stages mite density.And the searching effect on nymphs was decreased with temperature. The selective coefficient Q to egg, larva, nymps are 0.87,0.90,1.22.It was showed that when all steges of T. ludeni exist, Neoseiulus californicus will be preferred to select nymphs, instead of the egg and larva.Under the temperature gradient 19,22,25,28,31℃, researched the functional response of Neoseiulus californicus’on T. ludeni, the results showed that, under the different temperature, the functional response all belong to Holling Ⅱ types. Wthin 19-28℃, the predation ability (a/Th) of Neoseiulus californicus to T. ludeni increase with the rising of temperature. Under 31℃, the predation ability (a/Th) slightly decrease. It’s explained that temperature higher or lower will influence the predation ability of Neoseiulus californicus to T. ludeni.Studied the numerical response of Neoseiulus californicus to T. ludeni at 28℃.The results showed that, to a certain density range, with the density of T. ludeni nymphs increasing, the egg amount of Neoseiulus californicus also increased. Neoseiulus californicus feed on T. ludeni nymphs, the largest average oviposition are 25.67 eggs in ten days before the oviposition period. Only when the number of T. ludeni nymphs more than 16, the egg amount of Neoseiulus californicus can achieve a standard oviposition. |
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