Bioactivity of some indigenous plants for the control of hadda beetle, Henosepilachna vigintioctopunctata infesting brinjal
The present study was conducted to find out natural and cheaper source for the control of brinjal pest, Henosepilachna vigintioctopunctata, by the extraction of locally available plants. All the extracts prepared from different parts of the plants proved efficacious when first instar larvae were fed on leaves treated with 1.0% concentration and gave 80.0 to 93.3% larval mortality as against 6.7 ± 6.7% in control set. Flower extract of Eucalyptus globulus at 0.5% and seed extract of Nerium indicum at 0.2% increased total developmental period to 22.5 ± 1.5 and 22.7 ± 0.6 days respectively as compared to control in which larvae took 20.2 days to complete their development. The highest concentration (1.0%) of all the extracts also showed drastic effect on adult emergence while some abnormal adults with deformed wings, elytra and appendages were also observed in lower concentrations of N. indicum and E. globulus extracts. The LC50 values of these plant extracts also been calculated to compare their efficacy. The results show the insecticidal potentiality of N. indicum and E. globulus in the control of brinjal pest.