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一、发生种类危害西瓜的红蜘蛛种类主要有棉叶螨(Tetranychus urticae Koch)和神泽叶螨(T.kanzawa Kishida),此外,还有朱砂叶螨(T.cinnabarinus Boisduval)、苜蓿苔螨(Bryobia praetiosa Koch)等。据1989年初步观察,我地以棉叶螨为优势种。二、发生消长我地西瓜移栽一般在4月中旬至下旬。5月中旬,随着自然温度的升高,红蜘蛛从田边杂草、土中向瓜田移动,移栽后一个月左右,西瓜基部始见,以后随着温度的升高,红蜘蛛密度在下位叶迅速增殖,以后向中位叶、上位叶扩散,直至西瓜采收割藤,红蜘蛛密度仍不
First, the occurrence of types of red water spiders harm the main types of spider mites (Tetranychus urticae Koch) and T. kanzawa Kishida, in addition, there are spinnovar (T.cinnabarinus Boisduval), clover moss ( Bryobia praetiosa Koch). According to preliminary observations in 1989, I was the dominant species of cotton spider mites. Second, the growth and decline My watermelon transplants generally in mid-April to late. In mid-May, with the increase of natural temperature, the spider mites moved from weeds in the fields to the melons in the soil. About a month after transplanting, the base of watermelon began to see. After that, with the temperature increasing, Under the rapid proliferation of the lower leaves, and later to the median leaf, the upper leaves of the proliferation until the harvest watermelon vines, spider mite density is still not