1发生规律桑白蚧的发生每年2－5代，因地而异，北方一般为2代，以第2代受精雌虫于技条上越冬，次年3月中旬正值果树萌动之后开始危害；4月下旬开始产卵，4月底或5月初为产卵盛期，5月上旬为末期，卵期15天左右；5月上旬开始孵化，6月中旬开始羽化，6月下旬为羽化盛期；交屋后雌 1 occurring Sang white scale occurrence of 2-5 generations a year, vary from place to place, the North is generally 2 generations to the second generation of fertilized female over the winter on the technical terms, the middle of March the following year when the fruit trees began to damaging ; Spawning began in late April, the end of April or early May is the peak of spawning, early May for the end, the egg period of about 15 days; early May hatch, beginning in mid-June feather, late June feather peak ; After giving the house female