茶黑刺粉虱蛹和卵的发育分级及与其防治适期的相关性

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

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 。

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.