| Through the research, it can be found that, to Lithocolletis ringoniella Mats., six generations occur throughout a year, and the sixth generation occurs uncompletely. The occurrence periods are: the cross-winter generation occur mainly from the last ten days of March to the first ten days of April; The first generation, in the last ten days of May; the second generation, in the second and the last ten days of June; the third, the last ten days of July; the forth, the first ten days of September; the fifth, the from the end of September to the first ten days of October. During a year, adult bugs appear first in the second ten days of March, till the last ten days of October. It has the phenomena of generation overlap.Adult spawn in unfolding tender leaf, not in stopping growing leaf. in an apple tree, Larva's distribution belongs to ordinary binomial distribution. among apple trees, belongs to aggregated distribution, the degree of aggregation bumps up along with the raise of population density.Apple tree is harmed gently in the insect previous growth period, but as the amount of the insect increase quickly, upto the third-forth generation, the amount of the insect having arosed to the lever that can cause leaf desquamating, the fruit, tree growth are restrained, so lower the next year yield deeply.For short-term, it have been defined that the date for investigation in field can be based from pupation schedule , prevention and cure index can be based from natural enemy lethality, observe and predict conclusion can be based from the density of insect pityriasis simplex.In chemical control, from adult abundance to the data of first incubated larva eating into leaf, but not yet appearing mesh pityriasis simplex, it is effective for spilling insecticide in time to adult,ovum,young larva. To adult, Meothrin and Sumicidin are more effective, and to larva in macule, Chlorbenzuron and Meothrin are more effective.
|
PDF Full Text Request