Evaluation of Botanical Insecticides against flea beetles Podagrica sjostedti and Podagrica uniforma of okra

Field trials were conducted during 2012 and 2013 cropping season to assess the efficacy of aqueous extract of leaves and bulb of some botanicals for the control of two species of flea beetles (Podagrica sjostedti and Podagrica uniforma), important destructive pests of okra, in Southern Guinea Savannah, Nigeria. Okra variety NHV47-4 was used for the study. The treatments consisted of leaf extracts of neem (Azadirachta indica) and pawpaw (Carica papaya), and bulb extract of onion (Allium cepa) and untreated control. The experiment was laid out in a Randomized Complete Block Design and replicated three times. Data were collected on abundance of insects a day before botanical application and for the three consecutive days after spraying of insecticides. Yield parameters data collected were number of fruits, weight of fruit and yield of fruits. The results showed that all the extracts of the three botanicals significantly (P ? 0.05) reduced the population of the two flea beetles with the least percent efficacy of 56.4% and the highest 83.8%. However, pawpaw leaf extract had highest significant effect (P ? 0.05) in reducing the population of the beetles. The order of effectiveness in decreasing sequence was found to be pawpaw leaf extract ? neem leaf extract ? onion bulb extract. Onion bulb extract showed a moderate level of effectiveness with (63.9%; 56.4%) and (75.6%; 71.1%) on P. uniforma and P. sjostedti in 2012 and 2013 respectively. Pawpaw leaf extract showed the highest level of effectiveness with (79.7%; 81.5%) and (76.5%; 83.8%) on P. uniforma and P. sjostedti in 2012 and 2013 respectively. Higher yield, higher number of fruits and improved fruits’ weight of okra on treated plots indicated the efficacy of these botanicals. However, the effectiveness of neem leaf extract is comparable to pawpaw leaf extract.