Published online by Cambridge University Press: 29 May 2014
Maruca vitrata Fabricius (legume pod borer, LPB), the most serious economic pest of legume crops in the tropics, is primarily controlled by chemical pesticide application with serious consequences for the ecosystem and human health. In this study, various concentrations of three commercial biopesticides, NeemBaan®, Bactospeine® (Bacillusthuringiensis (Bt) subsp. kurstaki) and Florbac® (Btaizawai), were tested either in the field or laboratory or in both conditions. In the laboratory experiments, different concentrations of NeemBaan® exhibited significant effects on the mortality of all the tested larval instars and a mortality rate of over 80% was recorded at a dose of 3000 ppm. Bactospeine® was found to be more effective against M. vitrata than Florbac®. Bactospeine® applied at a lower dose of 500 ppm caused 100% mortality in the first-instar and second-instar larvae; however, at the same dose, Florbac® caused mortality of only 26.67% (first instar) and 20% (second instar). In the field experiments, a higher dose of NeemBaan® (6000 ppm) significantly reduced pod damage to approximately 20% in both the first and second cropping seasons. In conclusion, neem- and Bt-based biopesticide products have insecticidal potential to be used in an integrated pest management strategy for controlling M. vitrata in Thailand.