茶黑刺粉虱蛹和卵的发育分级及与其防治适期的相关性

20 0 0年 4～ 6月 ,每 5日在皖南黑刺粉虱Aleurocanthusspiniferus(Quaintance)常发茶园中以平行跳跃法选 5 0个样方。每样方为 1m茶行 ,查其上、中、下层各 2片成叶上各虫态粉虱的数量 ;采回 2 0 0头蛹于立体显微镜下解剖。越冬代蛹期 32～ 38d。据蛹体形态和颜色的显著变化而分为 4级 :体液乳白色( 1 2～ 1 4d)、体液淡黄色 ( 6～ 8d)、体液橙红色 ( 1 1～ 1 2d)和体液淡紫色阶段 ( 3～ 4d)。引入该粉虱于盆载茶苗上 ,观察其生物学习性。第 1代卵期 2 2～ 2 8d ,据卵颜色的显著变化分为 4级 :乳白色 ( 2～ 4d)、淡黄色 ( 2～ 3d)、橙红色 ( 1 5～ 1 7d)和紫黑色阶段 ( 3～ 4d)。第 1代幼虫期 2 5～ 2 8d ,其中 1龄 9～ 1 2d ,2龄 9d ,3龄 7d ,蛹期 7～ 8d。越冬代成虫盛期和第 1代 1龄盛期为防治适期 ,可较好地用蛹或卵的分龄分级法预测。越冬代蛹全部羽化之时 ,又恰是 1龄幼虫盛期 ,易于掌握

Developmental grade of pupae and eggs of white fly,Aleurocanthus spiniferus,in relation to its optimum control period of the pest in tea garden

During the spring of 2000,fifty sampling plots,each was 1 m tea row,were randomly selected at intervals of 5 days in tea garden in the Southern Anhui Province where white fly frequently occurred.The pest population on two matured leaves from upper,middle and lower layers of every plot was counted; 200 pupae were anatomized under the stereo microscope.The pupal stage lasted from 32 to 38 days,and was divided into 4 grades: milk white body fluid (12～14 days),primrose yellow body fluid (6～8 days),orange red body fluid (11～12days),and lilac body fluid (3～4 days).The 1st generation eggs went through 22～28 days,and divided into 4 grades: milk white (2～4 days),primrose yellow (2～3 days),orange red (15～17 days),and purple and black (3～4 days).The 1st generation larval stage lasted about 25 to 28 days,in which the 1st instar was 9～12 days,2nd instar 9 days,and 3nd instar 7 days.The pupal stage was 7 to 8 days.The adults of overwintering generation and the 1st instar larvae of 1st generation were the optimum stage for control,which could be forecast by the stage grade system.