芬兰真绥螨对苹果全爪螨的捕食作用研究(英文)

Predation of Euseius finlandicus (Oudemans) (Acari:Phytoseiidae) on Panonychus ulmi (Koch) (Acari:Tetranychidae) Orchard Trees

在实验条件下,系统研究了芬兰真绥螨Euseius finlandicus Oudemans对苹果全爪螨Panony-chus ulmi Koch的控制能力。研究结果表明:(1)在15～32℃的温度条件下,芬兰真绥螨雌成螨的捕食量随着温度的上升呈线型正相关。在15～25℃的温度内芬兰真绥螨的产卵量随温度升高而增加,在15℃下平均单雌产卵0.42粒,25℃时平均单雌产卵2.56粒;当温度升到32℃时单雌产卵下降为1.62粒,雌成螨的产卵量与温度的关系呈抛物线型。(2)在5～15头/叶的猎物密度下,雌成螨的捕食量随着猎物的密度增加呈线型正相关,而当猎物密度达到30头/叶时,芬兰真绥螨雌成螨的捕食量处于平稳状态。在5～15头/叶的猎物密度下,芬兰真绥螨的产卵量和产卵量均与猎物的密度呈线型正相关;当每头雌成螨捕食量为1.8～3.5头时,产卵量为1.0～1.5粒。(3)不同温度下,芬兰真绥螨对猎物的不同密度和虫态的功能反应可用圆盘方程II型进行拟合;在25℃条件下捕食效率最高且喜好捕食的虫态是卵和幼螨。

Panonychus ulmi （Koch） is a pest of apple orchards in Gansu, China. The predatory mite Euseius finlandicus （Oudemans） was explored as a potential biocontrol agent against P. ulmi in a series of experiments on its predation on P. ulmi. The rate of prey consumption （per predator female） increased linearly with temperature from from 6.83 at 15 ℃ to 23.88 at 32 ℃ （the relationship can be described by Y=-6.015 9＋0.869 5 T （R=0.9996）, whereas the rate of oviposition increased with temperature from 0.42 at 15 ℃ to 2.56 at 25 ℃ and then decreased to 1.62 at 32 ℃, the relationship can be described by Y= -9.804 2＋0.960 2 T-0.018 8 T^2 （R^2=0.984 9）. The rate of predation increased linearly with prey＇density within the range of 5-20 prey per leaf （Y = 0.523 9＋0.310 1 X, R= 0.998 8） but reached a plateau at the density of 30 prey per leaf. The rate of oviposition increased linearly with prey density within range of 5-15 prey per leaf; the relationship can be described by Y = -0.053 3 ＋ 0.136 0 X （R = 0.998 4）, As expected, the number of eggs laid by predators increased linearly with the number of prey they consumed （Y= 0.258 7 ＋ 0.335 9 X; R = 0.999 5）. On average, a predator consumed 1.8-3.5 prey to lay 1.0---1.5 eggs. Functional responses of predator to prey density at five different temperatures （15,20, 25, 28 and 32 ℃） and to different active life stages of spider mites （egg, larva, nymph, adult female and adult male） approximated Holling type Ⅱ. Euseius finlandicus was considered more effective against spider mites at 25 ℃ than at other temperatures. They are most effective against eggs and immature spider mites, but least effective against different the life stages of Panonychus ulmi.