EFFECTS OF BIOPESTICIDES AGAINST EPILACHNA DODECASTIGMA (COLEOPTERA: COCCINELLIDAE) ON PUMPKIN UNDER LABORATORY AND FIELD CONDITIONS

Abstract

Epilachna beetle, Epilachna dodecastigma (Wied.) is a destructive invasive pest in many parts of the world on cucurbit. To measure the toxicity of five biopesticides, a pilot experiment was conducted in the Entomology laboratory and research field of Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur, Bangladesh, during March to October 2017. Bioneem plus 1.0 EC and Ecomec 1.8 EC spraying were applied @ 0.05%, 0.10% and 0.15% while oils of neem, karanja and castor oils @ 5%, 7.5% and 10% concentrations. The effectiveness of the treatments against the pest was evaluated on the basis of percent reduction of beetle population; percent increased damage leaves at 24, 48, 72 HATs and 5 DAT and number of fruits and yields per plant in field level. In all spray intervals, mean percentage reduction of beetle population reached the peak point and the lowest percent increased damage leaves in Ecomec 1.8 EC @ 0.15% concentration treated plots. The number of beetle population decreased soon after spray but with increasing time the number of beetle population also increased. The highest (9.3) number of fruits were found in 0.15% concentrated in Ecomec 1.8 EC treated plot of 62.4 kg. The mortality of tested insect was observed 24, 48 and 72 HATs. In case of topical spray, the highest mortality 96.7, 93.3 and 83.3% of second instar larva, third instar larva and adult, respectively were recorded in Ecomec 1.8 EC @ 0.15% concentration at 72 HAT. In case of residual assay method, the highest mortality 93.3, 90.0 and 76.7% of second instar larva, third instar larva and adult were recorded in Ecomec 1.8 EC @ 0.15% concentration at 72 HAT, respectively. Percent mortality of beetle population increased with increasing time. All the tested biopesticides showed more or less toxicity effective against E. dodecastigma while the Ecomec 1.8 EC was the most promising to control this pest.