助迁、保护捕食性天敌控制桔全爪螨

报道了生防园和常规化学防治园中桔全爪螨及其主要天敌的种群数量动态。在春季助迁尼氏钝绥螨补充自然天敌数量的不足，结合其他天敌的作用，使试验期间生防园中桔全爪螨种群数量得到控制。而在常规化学防治园中，桔全爪螨密度大大高于生防园

CONSERVATION OF NATURAL ENEMIES TO CONTROL CITRUS RED MITE

Population changes of citrus red mite, Panonychus citri , in one bio con trol and one chemical control orchards in Guizhou province were investigated sep erately from early spring to late autumn, 1991. It was found necessary increase to the numbers of the natural enemies which were very low when the red mite num ber increased in early spring. The predator, Amblyseius nicholsi , was tran sferred twice by cutting twigs from nearby Chinese ilex ( Ilex purpurea ) to t he biocontrol orchard in mid April and May until it was adequate to suppress th e density of the prey. With the actions of other natural enemies (i. e. Steth orus punctillum, Quasimus sp. etc.), the density of the red mite was much lowe r in bio control orchard than that in chemical control orchard in following sea sons.