柑桔红蜘蛛(Panonychus citri (McG.))的初步研究

柑桔红蜘蛛为柑桔主要害虫之一,据在广东(?)平地区观察,此虫虫口消长与树令,夏、秋梢,有一定的关系,一般结果树受害轻;幼苗受害严重。每当夏、秋梢老熟时,正值红蜘蛛出现高峯。该虫完成一世代的历期,与温度有关:2—5月,完成一世代的历期31—41天;6—10月,历期20.25—27.00天。每头雌成虫产卵7—113粒。药剂防治以600—800倍20% T.D.N 效果最好;2,000—6,000倍乙基1059次之;0.4°波美的石硫合剂、0.4°波美的多硫化钡等残效期较短。

A PRELIMINARY STUDY ON THE CITRUS RED MITE (PANONYCHUS CITRI (MCGREGOR))

Panonychus citri (McG.) is widely distributed in the citrus-growing districts of Hupeh,Kiangsi,Chekiang,Fukien,Kwangtung,Yunan,and Szechuan provinces.It is considered as the most serious pest in the citrus orchards of Kwangtung.Studies on the life history and habits of this insect were conducted at Swatow to find out some effective control measures.In the vicinity of Swatow,this red mite has about 18 generations a year.The adult stage lasts for 11.03-20.00 days in average.Each female may lay 32-42 eggs,which require 4.61-11.06 days to hatch.Both the larval and the protonymphal stages require 0.5-2.0 days.The deutonymphal stage lasts for 1.5-4.0 days.It takes 19.00-41.00 days to complete one generation.Infestation of the citrus red mite results in severe injury to the leaves,tender fruits and green bark of citrus trees,the injured parts can not develop properly and fall off prematurely.The less damaged leaves become spotted and lose their natural glossy green color.Among the insecticides tested 1/600-1/800 spray of 20% Tedion,1/2000-1/600 spray of 50% Systox,0.4 Be lime-sulphur or 0.4 Be BaS.Sx were proved to give very successful control.