Abstract:
Crops in the Family Malvaceae are attacked by various insect pests at different stages of their development especially Podagrica species (Coleoptera: Chrysomelidae). The emergence of biodegradable pesticides (botanicals) as safe option has reduced the problems that result from the use of synthetic insecticides, thus creating a renewed interest in their development and use in integrated pest management of crops. Therefore, field experiments were conducted to investigate the control capability of water extracts of Piper guineense seeds and Cypermethrin on flea beetles (Podagrica spp. infesting okra (Abelmoschus esculentus (L.) Moench). The experiment was conducted in two locations in the rain forest zone of Nigeria. The first experiment was conducted at the Teaching and Research Farm of The Federal University of Technology Akure, Ondo State (Early cropping season of 2011), while the second experiment was carried out in Ado-Ekiti (Late cropping season of 2011). A synthetic insecticide (cypermethrin) was included in the treatments as a standard check alongside the untreated (control). The experimental design used was a Randomized Complete Block Design (RCBD) with five treatments replicated three times. The effectiveness of the treatments was determined based on reduction in the population of the adult insects. The results from the study showed that water extract of Piper guineense seeds and the synthetic insecticide significantly (P < 0.05) reduced the population of the flea beetles when compared with the control. The synthetic insecticide treated plots produced the highest pod yield, but this was not significantly different from the dried yield recorded in the plots sprayed with aqueous extracts of P. guineense seeds. The results of field trials in both cropping seasons in 2011 showed that all the treatments significantly suppressed infestation by the flea beetles throughout the period of observation. In view of the ability of water extract of P. guineense seeds to control the infestation of Podagrica spp., its use by resource poor farmers is therefore recommended.
