Studies On The Artificial Rearing Technology Of Delphastus Catalinae(Horn)

Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), has broken out and caused serious damage to agriculture in all countries in the world. The use of natural enemies is one of the most important components of any IPM program toward it. In this study, the artificial rearing technology of Delphastus catalinae (Horn) (Coleoptera: Coccinellidae) was studied, in order to provide technology and theoretical basis of biological control of whitefty with Delphastus catalinae. The main results obtained were as follows:1. Bemisia tabaci prefers to cauliflower, tobacco, poinsettia, cowpea and tropic ageratum. Not only the quantity of Bemisia tabaci is more on the five plants (12.270-45.844 heads/per leaf), but also its survival rate, adult oviposition and the population growth index (I) are higher. In all of the experimental plants, cauliflower is the best host plant for mass rearing of Bemisia tabaci, with the maximal population growth index (1) of Bemisia tabaci developed on it (44.62).The leaf rigidity, the quantity and character of leaf hair, the excitant odor from leaf of host plants can affect the feeding choice of Bemisia tabaci, and the nutrition content of the plant leave can also affect that. However, the content of crude protein and crude fat in the plant leave have a positive correlation with the quantity of Bemisia tabaci (r=0.1814 and r=0.1261). The content of soluble sugar and crude fibre in the plant leave have a negative correlation with the quantity of Bemisia tabaci (r=-0.0099 and r=-0.5197).2. Delphastus catalinae also shows a choice to the host plants. The quantity of Delphastus catalinae is more on tobacco, cauliflower, poinsettia and tropic ageratum (0.220-0.562 heads/per leaf). The population of Delphastus catalinae on different host plants is mainly affected by the whitefly quantity, with the close relationship (r=0.6911 ). The leaf hair of host plant can affect the crawl velocity and the predatory quantity of Delphastus catalinae. At the same time, the host plant influences the development, survival and propagate of Delphastus catalinae significantly. According to the innate capacity of increase (r_m) of Delphastus catalinae, the six host plants arranged are cauliflower (0.0771), tropic ageratum (0.0722), cowpea (0.0714), poinsettia (0.0677),swcetpotato (0.0640) and tobacco (0.0540). From the view of mass rearing of Delphastus culalinae, cauliflower is the first choice for the host plant, and followed by poinsettia, cowpea and tropic ageratum.3. The egg of Bemisia tabaci is the most favor food for Delphastus catalinae in three stages of host whitefly. After preyed it, Delphastus catalinae develops quickly (egg to adult 23.32d), with high oviposition (131.25 eggs/-?) and fast population growth Cl-1.0751).4. The predatory behavior of adult Delphastus catalinae consists of six acts: searching, feeding, grooming, resting, wingspreading and excretion. The larva has the same but without wingspreading. Delphastus catalinae uses the method of trial and error to feed. At one time, it mainly adopts the strategy of actively searching, once in a way is sitting back and wait.The searching efficiency of female Delphastus caialinae is higher than male, because their feeding time are a little difference (8.11 min (ï¿¡) and 7.90min ( t> )), and the searching time of female is 7.83min shorter than male. The adult likes to feed the whitefly egg, the feeding time to egg is 26.39 times than to nymph, but the larva likes to feed the whitefly nymph. Starvation can make Delphastus catalinae add the searching time and improve searching efficiency, in order to increase its predatory quantity. If the prey density is too low, Delphastus catalinae will switch to sit back and wait, so the resting time will prolc.g. Feeding experience can accelerate Delphastus catalinae to feed.5. In two kinds of basic artificial diets, we found primary content with egg^ bee pollen and drone pupa has better feeding effect. After feeding these kinds of artificial diets, adult Delphastus catalinae can prolong the longevity accordingly (>30d) and even oviposite accidentally (1 egg). The artificial diet should be made to liquid state, and is pushed between two layers of plastic film to let Delphastus catalinae to feed. This way is good to keep the diet fresh and avoid Delphastus catalinae to be adhered to diet. Olive oik honeydevv and sugar are the better feeding irritant. The whitefly body may have kairomonc that can allure Delphastus catalinae to feed. If the artificial diet added with the whitefly egg or nymph serosity or the plant leaf serosity with whitefly, the feeding effect will be improved.6. Most of the artificial diets can prolong the longevity of adult Delphastus calaliiuiL', even to two months, but almost no oviposition. The oviposition of adult...