【摘要】 白蜡绵粉蚧 ( Phenacoccusfraxinus)在西宁市 1年发生 1代 ,2个龄期。 3月中、下旬雌雄若虫分化、结茧化蛹 ,4月上旬开始羽化 ,5月上旬产卵 ,6月中旬开始孵化 ,8月下旬 1龄若虫开始蜕皮 ,1 0月上旬 2龄若虫开始在白蜡树皮裂缝、翘皮下、芽鳞间、树杈、侧枝背阴面结茧越冬。白蜡绵粉蚧在西宁市的城西、城中、城南、城东区的危害率分别为 95 .7%、79.2 %、62 .2 %、3.4%。更多还原

【Abstract】 Phenacoccus fraxinus occurs just one generation and have two instars in a year. The over winter nymphs differentiate into female nymphs and male ones, and then male ones become cocoon pupation on the second or the last ten days of March, eclosion of adult insects occurs on the first ten days of April, oviposition on the first ten days of May, eggs begin hatching on the second ten days of June, ecdysis of one instar nymphs on the last ten days of August. Under the raise bark, or within crevice bark, or inside scale and bud, and in the shady place of crotches and branches of the trees ( Fraxinus chinensis ), two instar nymphs start cocooning and over winter on the first ten days of Octomber. Damaged rate of Phenacoccus fraxinus were 95.7%, 79.2%, 62.2% and 3.4% respectively on the west, middle, south and east areas of Xi’ning city.更多还原