Biocontrol efficiency on Spodoptera litura (Fabricius) in Qiannan tobacco growing areas

In order to reduce the use of chemical pesticides and effectively control pests in tobacco fields, the control efficiencies of seven biopesticides (32000 IU/mg Bacillus thuringiensis wettable powder, hexaflumuron 5% EC, 0.3% matrine, 2 billion PIB/mL polyhedral virus suspension, 240 g/L methoxyfenozide suspension, 0.6% azadirachtin emulsion concentrate and 60 g/L spinetoram suspension) on larvae of Spodoptera litura (Fabricius) in tobacco fields were investigated. The results showed that the control efficiencies of 0.3% matrine (applying at a rate of 3.0-4.0 g a.i/ha) and 240 g/L methoxyfenozide suspension (applying at a rate of 120 g a.i/ha) were higher than those of the other agents, which reached 85.0%-92.6% and 80.6%, respectively on the 14th day after application. Therefore, matrine and methoxyfenozide can be used as biopesticides against Spodoptera litura (Fabricius).