Abstract:

To evaluate the risk of Bactrocera dorsalis to peach, ‘Okubo’, ‘Kawanakajima’, ‘Zhongpan 11’, ‘Daifei’, ‘Zhonghuashoutao’ and the immature, nearly mature and mature fruits of ‘Laishanmi’ were selected as materials to explore the oviposition amount of B. dorsalis on different varieties and three mature degrees of peach. Then the physiological indexes were determined to analyze the correlation between fruit quality and the oviposition amount of B. dorsalis. And several kinds of fruit bags commonly used in production were selected to test their blocking effect on the oviposition of B. dorsalis. The observation of peaches of different colors showed that B. dorsalis preferred to lay their eggs on the bright red peaches, followed by the yellow peaches, and the least favorite was the green peaches. There was also a significant difference in the oviposition amount in different varieties of peaches, in an order of ‘Kawanakajima’> ‘Okubo’> ‘Daizong’> ‘Zhongpan 11’. Among the fruits with different maturity degrees, the oviposition amount was in an order of near mature> mature> immature. And the results showed that paper bag and transparent plastic bag could completely block the oviposition of B. dorsalis on peach fruit, while non-woven bag and 60 mesh bag could partially block the oviposition. The preference of B. dorsalis to different peach varieties and fruit maturity was determined. Oviposition preference is affected by fruit color, pericarp structure, pulp hardness and other factors. Fruit color changing period is the key control period of B. dorsalis. Selecting fruit bags with good light transmittance and small pores for secondary bagging can not only control the damage to B. dorsalis to mid-late ripening peach, but also ensure the coloring and improve the sugar content.

Key words: Bactrocera dorsalis, peach, oviposition preference, fruit maturity, fruit bag