| dc.description.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. | en_US |
