昆明桃园梨小食心虫发生规律

2011-2013年对昆明桃园梨小食心虫发生规律及为害特点进行了系统调查研究。结果表明:3年来昆明地区梨小食心虫发生趋势基本一致,但各年度发生的大高峰期有差异,2012年成虫发生大高峰期为越冬代、第一代;2013年成虫发生大高峰期在第二、三代,这与当时的温度、降水量有很大关系。昆明梨小食心虫一年发生4代,越冬代成虫发生高峰期在3月中旬至4月上旬,第一代发生高峰期在5月上旬至6月中旬,越冬代、第一代主要为害桃树新梢,新植桃园幼虫更趋向在低龄桃树为害,幼虫蛀梢的高峰期在成虫羽化高峰期后15~30d;第二、三代发生高峰期在7月上旬至9月下旬,世代重叠明显,后两代主要为害果实。经饲养观察,桃园梨小食心虫性比[♀/(♀+♂)]为0.57~0.64,幼虫被天敌寄生率为26.9%,幼虫蛀果率为1.25%~5%。

Occurrence pattern of Grapholitha molesta (Busck) in peach orchard in Kunming

Potato late blight caused by Phytophthora infestans is the most devastating disease in potato production. It is of great importance to clear the mating type of P. infestans and metalaxyl sensitivity for prevention and control of potato late blight. In this study, we measured the mating type and metalaxyl sensitivity of P. infestans strains collected from Heihe, Qiqihar, Suihua and other main potato producing area in Heilongjiang Province during 2011-2013. Mating type determination by dual culture method demonstrated that, among 153 strains, 79 strains were A1 mating type, accounting for 51.63%; 74 strains were A2 mating type, accounting for 48.37%. Metalaxyl sensitivity test by colony diameter method showed that 83.92% were highly resistant among all the 143 tested strains, 8.39% were moderate resistant and 7.69% were sensitive.