| Euseius finlandicus (Oudemans) belongs to Phtoseiidae, Acariformes, Acari, Arschnida. It distributes in many countries including China, where it distributes extensively and inhabits plenty of plants, preying many species of phytophagous mites. In biological control it has vast potential in controlling mites. Recently, because many pesticides have been abused, lots of natural enemies had been killed too, and the mites break out massively, whose resistivity to pesticides has been enhanced rapidly, which made it more urgent to control Tetranichidae by utilizing natural enemies in biology control. In this paper, we have bred Euseius finlandicus using water-tray method and observed its biology and food habit, and studied its functional response, which offered a theoretic reference. The contents are as follows: l.The development stages and amount of spawned egg of Euseius finlandicus,On the indoor condition(20 ℃ -28℃). Euseius finlandicus has five stages. including ovuiru larvas first nympha> last nympha> adult. The ovum stage is about 2.0 days, larva stage is 0.8 days, first nympha stage 0.6 days, last nympha stage 0.9 days, adult stage 18.6 days, preoviposition period 1.0 days, oviposition period 16.0 days, after-oviposition period 1 .5 days, amount of spawned egg per female adult per day 42.9 granules, ratio of female to male 4:1 and the mating-time 2.2 hours. Within the range of temperature from 15'C to 32癈 . the development time is shortened and amound of spawned egg per female adult per day increase with the tempereture rising.2. Food inhabitEuseius finlandicus preys plenty of species of mites such as Tetranychus viennensis^ Pananychus ulmi , Oligonychus ununguis ect, which eats some of pollen. In this paper, we had bred Euseius finlandicus with five species pollen, and discovered that Euseius finlandicus only ate some of pollen of Hibiscus syriacus and hardly ate other pollen in this five species pollen.3. The predacious functionIn this experiment, we use Moiling II and new III fitting the formula of the functional response of Euseius finlundicus on Oligonychus ununguis based on the data from experiment. The results suppose that Moiling II is better fitting the functional response that the each stage of Euseius finlundicus (larva, nympha and adult) prey on the each stage of Oligonvchus ununguis (larva, numpha and adult). The temperature and the size of the habitat can affect the parameter of the functional response, but donot change the category of the formala. In this, the relationship between the instantaneous rate of discovery and the temperature is the quadratic function ,which shows that within the range of temperature ,the preying activity of Euseius finlandicus will increasing with the temperature. When the temperature beyond the definite scope, the activity will decrease and the instantaneous rate of discovery will decrease too. While the relationship between the time spent handling and the temperature is the cubic function, because that it is affected not only by the hunting rate, but also by the temperature. The handling time will decrease with the increase of the hunting rate. When the temperature beyond specific scope, the handling time will severely shorten. 4. The interference responseThe result of the interference response supposes that the rate of the predacious rate of Euseius finlandicus will decrease with the increase of the density of the predator. When the density of the predator is lower, E will decrease quickly. With the further increase of the density of predator, E will decrease slowly.5 The selective effect for the stage of the preyThe study shows that there are distinct differences in the favorite level for the different stage of Oligonychus ununguis in Euseius finlandicus . Adult is the preferable prey. Following are larva and nympha. Egg is distasted.6 The prospect of the applicationEuseius finlandicus is one of the superior natural enemies, which have wide distribution ,large population number in field, wide feeding habits and high efficiency of...
|
PDF Full Text Request