柑桔锈螨(锈壁虱)在金堂地区发生严重而普遍,是柑桔树全年生长中为害时间很长的害虫之一。果实被害一般30％左右,受害严重的树势,要在二、三年后,才能恢复起来。锈螨的盛衰,与当年气候条件和越冬虫口存亡情况有密切关系,如1975年12月,金堂寒冷,绝对最低温度-14.8℃,持续近二小时,为过去多年所罕见,第二年又遇伏旱,致锈螨延至9月下旬才大量发生为害。据近几年在野外观察,日平均温度28℃左右时,虫口迅速增加,在金堂常年7月至9月上、中旬是其发生猖獗时期。1965年7月尾,当日气温30.3℃时,桔叶上的虫口密度达到全年中的最高峰,用视野取样镜检50片 Citrus rust mites (rust ticks) in Jintang area is serious and widespread, citrus trees are perennial one of the long-term pests. About 30% of the victims of the fruit are generally harmed, severely affected by the tree, to be restored in two or three years. The rise and fall of rust mites, and climatic conditions and the prevalence of overwintering insect population are closely related, such as in December 1975, Jintang cold, the absolute minimum temperature of -14.8 ℃, lasted nearly two hours, rare for many years in the past, the second year and the case Volt drought, rust mites delayed until late in September a large number of harm. In recent years in the field observation, the average daily temperature of about 28 ℃, the population increased rapidly, in Jintang perennial July to September, the middle of its rampant period. At the end of July 1965, when the temperature was 30.3 ℃ on the same day, the density of insects on orange leaves reached the peak of the year, and 50 samples