茶短须螨的生物学特性和防治研究

茶短须螨(Brevipalpus obovatus Donnadieu)是茶树上一种重要害螨。寄主范围广,能为害45科120多种植物。全年发生7代。以雌成螨在表土下根颈部越冬,但在我国南方茶区则无明显的滞育现象。螨体和卵多分布于茶树中、下部,以成叶或老叶的背面居多。雌、雄性比约2000∶1,以行孤雌生殖为主,也可行两性生殖,后代绝大多数为雌螨。雌成螨平均寿命为35—46天,长的可达6个月,平均产卵量35—40粒。在杭州地区,每年4月份平均气温上升至10—15℃时开始出蛰;24—30℃为适温范围,8月中旬—

Bionomics and Control of Tea Scarlet Mite

Tea scarlet mite(Brevipalpus obovatus Donn.)is an important mite pest of teabush in the eastern and southern tea area of China.It has a wide host range,itdamages more than 120 species of plants which belongs to 45 families.There are 7generations per year and is overwintered as the female imago in the part of root neckunder the soil surface.It does not come into the diapause condition in the southernpart of China.The mites and eggs are mainly distributed in the middle or lower partof tea bush,and most abundant on the undersurface of the mature leaf and old leaf.The sex ratio of female to male is about 2,000:1,The mite's reproduction is mainlyparthenogenesis,it can be digenetic reproduction too.The overwhelming majority ofthe progeny are female.The longivity of the female imago averaged 35—46 days,themaximum is 6 months.The female deposits an average of 30—40 eggs.The femaleimago began to migrate from the part of root neck to the canopy when the ambienttemperature of April is risen to 10-15℃ in Hangzhou.The optimum temperature is24-30℃.During the period of the mid of August to the mid of September,when themean ambient temperature in the period of ten days is higher than 24℃,the rainfallis larger than 40mm,the cumulative sunlight is more than 60—100hr,the populationwould be appeared a peak after 20-30days.There are two peaks of population arounda year.When the mean ambient temperature is lower than 17℃,the female imagobegan to diapause.In the end of autumn tea season(mid of October),spraying withthe 0.5°Be lime-sulfur in the tea garden,the overwintered female imago can be killedeffectively.The application of the cotton-oil soap(50×dilutions)(?)(safety interval 7—10days,tentative),500% plictran 4000—6000×dilutions and 20% Amitraz 1000×dilution s(safety interval 15 days,tentative)before the peak emergence performed agood miticidial activity and combined with the ovicidial activity.