Received: 22-07-2015 / Accepted: 01-12-2015
The sedge stem borer Bactra venosanaZeller isconsidered as one of themajor pestsonsedge. The studywas carried out to examine the biological characteristics of B. venosanaunder semi-natural conditions (green house)int Nga Son, Thanh Hoa. Themean developmental time was from 55.82 ± 0.90 days, 44.57 ± 0.87 days and 33.07 ± 0.82 days at 21.83 ± 0.74oC, 25.89 ± 0.89oC and 29.83 ± 0.71oC, respectively.The number of eggs laid by a female was 69.13 eggs at 25.4oC and 91.93%RH. The egg hatching percentage was high 84,1-90,1%. Male adult longevity was significantly shorter than thefemales.