Comparative Efficacy of Insecticidal Plants on the Management of Groundnut Bruchid (Caryedon Serratus)

Abstract

Laboratory study was conducted to determine the efficacy of insecticidal plant extracts Azadirachta indica A. (Juss), Lantana camara L. (Verbenaceae), Eupatorium odoratum L. (Asteraceae), Tephrosia vogelii Hook, Afromomum melegueta K.M. (Schumann) and Ocimum gratissimum (L) leaves against groundnut bruchid beetle (Caryedon serratus), and a synthetic insecticide (Cypermethrin) (10EC)) under ambient condition of temperature and relative humidity (30°C and 72%). One hundred grams of shelled groundnut was weighed into jute bags and treated with powders of the insecticidal plants. Both treated and untreated bags of groundnut were then infested with newly emerged adult of C. serratus (20 per bag) and covered. The experiment was laid out in Completely Randomized Design (CRD) and replicated four times. Parameters assessed included number of egg oviposited, number of eggs hatched (eclosion) and number of adults that emerged from each treatment, total developmental period (egg – adult), sex ratio of the emerged adults and finally percentage germination of the treated seeds. Data collected were analyzed using analysis of variance and treatment means were separated using Duncan multiple range tests at P ≤ 0.05 level of significance. Results showed that A. indica, L. camara, T. vogelli, A. melegueta and O. gratissimum treated seeds significantly recorded lowest mean number of eggs, reduced damage by C. serratus and increased germination percentage compared with E. odoratum and control. In conclusion, A. indica, L. camara, T. vogelli, A. melegueta and O. gratissimum have the potentials as alternatives to synthetic insecticides in the management of C. serratus by resource poor farmers.