应用智利小植绥螨防治温室四种花卉上二斑叶螨的研究

在温室栽培的一串红、藿香蓟、马蹄莲和爬蔓绣球上释放智利小植绥螨防治二斑叶螨均取得满意的结果。早期(10—11月)释放捕食螨,可减少花卉受害,节省捕食螨数量。于苗期或分盆前释放,还可节省用工。智利小植绥螨的释放量,因叶螨密度、花卉种类、植株大小而异,每次每株释放1—50头不等。3—4月初,如叶螨数量有回升,可释放第二次。一般能控制害螨每叶一头以下。

BIOLOGICAL CONTROL OF THE TWO SPOTTED SPIDER MITES WITH PHYTOSEIULUS PERSIMILIS ON FOUR ORNAMENTAL PLANTS IN GREENHOUSES

Infestations of four commercial ornamental plants, Scarlet, sage (Salvia aplendens), ageratum (Ageratum cony-zoides), trumpet Zahtedeschis aethiopica) and ivyleaved pelargonium (Pelarqonium laleripes),by, Tetranychus urticae in greenhouses were successfully controlled through releases of the predacious mite, Phytoaeiulus paraimilia in Beijing from 1984 to 19S5. The predator effectively aupreaaed the pest density to a level of leas than one pest mite per leaf. The releases were conducted during October to November, when the plants were in seedling stage or densely cultivated in nursery plots and the peat population began to increase, This timing for the releases has been found to be effective and economical. The releasing rate for the predator varied from 1 to 50 per plant, depending upon pest density and plant apeciea and size. A second release were sometimes necessary if the peat population became high during March to early April.