关键词: 金龟子绿僵菌, 桃小食心虫, 土壤, 土壤接种, 夏玉米, 叶片衰老, 水氮耦合, 控释尿素

Abstract: The development process and quantitative dynamics of Metarhizium anisopliae in soil and its potential in controlling Carposina nipponensis are studied.The results show that the number of its colony forming units CFU is declined by more than 80% in all treatments after 62～82 days,and by more than 99% after 121～234 days.The half-life of initial inoculum are 28.5 and 23.8 days for conidia and 26.9 and 19.6 days for mycelia in sterile and non-sterile soil,respectively.With C.nipponensis cocoons containing larvae introduced 100 days after soil inoculation,their infection is compensated for the decline,and fungal recovery is 1000 times larger in 278 days than in 271 days after inoculation without cocoons.The mortality of C.nipponensis larvae introduced at different time after soil inoculation is remained by more than 90% by day 131,and is declined to 9.3% by day 237.C.nipponensis is not infected in untreated soil. In plot trials, 97～100% of larvae are killed with doses of 15,22.5,30 and 37.5 kg conidial preparation per hectare,and the rates of bored fruit are 2.7～5.0%.Pilot tests are conducted with an application rate of 22.5 kg·hm^-2in 670 hm² of north Shaanxi.The rate of bored fruit is reduced from 30% for untreated orchards to 2.4% for treated ones.

Key words: Metarhizium anisopliae, Carposina nipponensis, Soil,Soil inculation, controlled release urea, leaf senescence, summer maize, water and N coupling