The Occurrence And Physical Control Techniques Of Pear Gall Midge (Dasineura Pyri), Oriental Fruit Moth (Grapholitha Molesta) In The Northwest District Of Zhejiang Province

Pear is one of kinds of traditional fruit of Zhejiang province, which is also one of the majorindustries of farmer rich. But there are many kinds of pests which caused damage seriously. Currentlycontrol method of pear pests based mainly on chemical control measures, due to the abuse of pesticides,resulted to exceed of pesticide residues, pollution of environmental and threaten of the safety of fruit. Inthis paper, occurrence characteristics of the main insect pests of pear and the application of physicalcontrol techniques were studied, and identification table of insect pests of pear was made firstly in orderto provide a scientific basis for the sustainable development of the pear industry in Zhejiang province.The results were as followings:(1) The homology of two kinds of pear gall midges fed on flowers and leaves was studied throughtesting the mitochondrial cytochrome oxidaseⅠ(COⅠ) gene. The results showed that they belonged tothe same species, but there were some differences in gene sequences.(2) The relationship between occurrence of gall midge fed on pear flowers, Dasineura sp. anddevelopment of pear flowers was studied with the methods of labrotary rearing and field survey. It wasfound that Dasineura sp. emerged from the end of February and ended at the end of March, and damageperiod could reach12to19days. The population fluctuation belonged to the single peak type. The ratioof flower bud formation (x) and damage percentage (y) of Dasineura sp. was exponential relationship: y=8.4951e0.0167x，r2=0.5274. The occurrence of pear blossom gall midge, Dasineura sp. is closely relatedwith weather conditions, and high temperature, drought and longer sunshine were favored to theoccurrence of pear midges, lower temperature and rainy, shorter sunshine were not favored to theoccurrence of the insect pest.(3) Attractant effects of10different colors and3different heights of sticky boards on pear gallmidge, Dasineura sp. were investigated in pear orchards. The results showed that yellow sticky boardwas the best color for traping the gall midge, the average number of Dasineura sp. trapped was76perboard at the most,and much more than other colors (P <0.05). Traping number of black boards was theleast with the average of0.67to15.67, and had some repellent to Dasineura sp.. More Dasineura sp.were trapped on boards placed from0.5to1meter aboveground than other heights. Further analisisfound that the colors of sticky borad, periods of the place and heights of place had significant difference (p<0.05) in trapping numbers, and the interactions between colors and heights, colors andperiods, heights and periods, and the interactions of colors, heights and periods had very significantdifference (p<0.01) in trapping numbers.(4) Effects of four different traps, four different lures and two placed heights on trapping efficiencyof Grapholitha molesta (Busck) adults were studied in pear orchard of Tonglu County, Zhejiangprovince in the paper. The results showed trapping effect of triangle shape and ship shape traps wasextremely significantly higher than those of cage shape and basin shape traps, in which there was nosignificant difference in trapping effect between triangle trap and ship shape trap, and between cage trapand basin shape trap, respectively. But the order of relative trapping efficiency was triangle shape trap>ship shape trap> cage shape trap> basin shape trap. Different lures had no obvious difference intrapping effect, but the relative trapping efficiency of Pherobio Technology Co. Ltd.’s was better.There was no significantly different in trapping efficiency between one meter height and two meterheight placed lure. The conclusion will provide a scientific basis for effectively monitoring andcontrolling the population of the insect pest by rational utilization of the sex attractant for Grapholithamolesta.(5) Effects of10kinds of fruit bags and3periods of application on the occurrence of pests, fruitsize, weight per fruit and sugar content of pear fruits were conducted. The results showed that baggingcan effectively reduce pests damage, improve skin color of fruit and its’ marketability. The control effecton pests and diseases of bag II, III, VII and VIII were better, especially bag II. Different bagging periodhad certain effects on the fruit’s length and breadth, average weight per fruit and sugar content of fruit.The earier the period of baging fruit was, the shorter (smaller) the fruit’s length and breadth and fruitweight were. But the sugar content of baging fruit was lower than that of control treatment (CK).