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Array of pest complex and yield reduction due to insect pests is one of the major constraints for low productivity of cowpea. The insecticidal efficacy of Spondias mombia, Momordica charantia, Mitrocarpus villosus and Chenopodium ambrosioides crude aqueous extracts was assayed for suitability in controlling the pod-sucking bug Clavigralla tomentosicollis Stâl (Hemiptera: Coreidae) on cowpea. The field experiment was laid out in a randomised complete block design with two treatments replicated three times at the Teaching and Research Farm of Rufus Giwa Polytechnic, Owo, Ondo State, in 2012. One kilogram of plant leaves was pounded using mortar and pestle and soaked in 3 L of cold water overnight. The extracts were applied at 10% (v/w) and sprayed every week for four weeks and a synthetic insecticide (Lambda cyhalothrin) was used as reference to compare the effectiveness of the plant extracts. Results of the experiment show that the plant extracts caused considerable reduction in the insect population; similarly, yield attributes corresponded positively with the effectiveness of the treatment and were at par with the synthetic insecticide. However, among the plots treated with aqueous plant extracts, the plot treated with S. mombia performed better than other plant extracts in terms of number of uninfested pods (55.34), plots treated with C. ambrosioides, having least number of damaged (infested) pods (6.0), and plots sprayed with S. mombia, having highest number of harvested pods (62.67), uninfested pods (55.34) and seed weight (0.18 kg). This study is probably the first reported case of the potential of the evaluated plant extracts for the control of insect pests of field crops. Therefore, the present study suggests the use of all the tested plant extracts, as they have been found to be very promising biopesticides in the control of cowpea pod-sucking insect pests. Thus, the extracts could be a good alternative to the synthetic insecticides on organically managed farms as well as on farms of limited-resource farmers in the tropics and subtropics. © 2014 © 2014 Taylor & Francis. Source

Mobolade A.J.,Soil and Pest Management Technology | Ejemen I.J.,Federal University of Technology Akurre | Rufus J.A.,UK Defence Science and Technology Laboratory | Festus E.A.,Rufus Giwa Polytechnic
Archives of Phytopathology and Plant Protection | Year: 2014

Crops in the Family Malvaceae are attacked by various insect pests especially Podagria species (Coleoptera: Chrysomelidae) at different stages of their development. 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 experiments were 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 (2011 Early cropping season), while the second experiment was carried out at the Teaching and Research Farm of Rufus Giwa Polytechnic, Owo, Ondo State (2011 Late cropping season). A synthetic insecticide (Cypermethrin) was included in the treatments as a standard check alongside the untreated (control). The experimental design was laid out in a randomised complete block design 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 showed that water extract of P. guineense seeds and the synthetic insecticide significantly (p < 0.05) reduced the population of the flea beetles as compared with the control. The synthetic insecticide-treated plots produced the highest standard check, 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 showed that all the treatments significantly suppressed the infestation by the flea beetles throughout the study period. In view of the ability of water extract of P. guineense seeds to control the infestation of Podagrica spp. its use by farmers is therefore recommended. © 2014 © 2014 Taylor & Francis. Source

Adesina J.M.,Soil and Pest Management Technology | Ofuya T.I.,Federal University of Technology Akurre
Jordan Journal of Biological Sciences | Year: 2015

The efficacy of oil extracted from the leaves of Secamone afzelii was evaluated in the laboratory against Callosobruchus maculatus infesting stored cowpea. Leaf extracts from S. afzelii were obtained through the soxhlet extraction method using methanol and hexane as the solvent. Each of the extracts was tested by exposing five pairs of adult beetles to various levels of 0.5, 1.0, 1.5 and 2.0 ml corresponding to 2.5, 5.0, 7.5 and 10.0% v/w concentrations admixed with 20g cowpea in three replications respectively, in a Completely Randomized Design (CRD). Control treatment was set along. The results showed that oviposition and percentage egg hatched were significantly (P <0.05) suppressed on seeds treated with higher treatment level of extracts. Leaf extract with hexane at 2 ml (10.0% v/w)/20g cowpea seeds was most effective in suppressing oviposition and egg hatched. Therefore, S. afzelii exhibit promising degree of oviposition deterrent and ovicidal properties and, thus, have a great potential for use as a plant-based biopesticide as an alternative to synthetic insecticides for controlling C. maculatus infestation on stored cowpea grains. © 2015 Jordan Journal of Biological Sciences. Source

Adesina J.M.,Soil and Pest Management Technology | Adesina J.M.,Institute of Bioresources and Sustainable Development | Jose A.R.,Environmental Biology Unit | Rajashaker Y.,Institute of Bioresources and Sustainable Development | Afolabi L.A.,Soil and Pest Management Technology
Jordan Journal of Biological Sciences | Year: 2015

The cowpea beetle, Callosobruchus maculatus (Fabricus) (Coleoptera: Chrysomelidae), is a major pest of stored cowpea militating against food security in developing nations. The comparative study of Xylopia aethiopica and Aframomum melegueta powder in respect to their phytochemical and insecticidal properties against C. maculatus was carried out using a Complete Randomized Design (CRD) with five treatments (0, 1.0, 1.5, 2.0 and 2.5g/20g cowpea seeds corresponding to 0.0, 0.05, 0.075, 0.1 and 0.13% v/w) replicated thrice under ambient laboratory condition (28±2°C temperature and 75±5% relative humidity). The phytochemical screening showed the presence of flavonoids, saponins, tannins, cardiac glycoside in both plants, while alkaloids was present in A. melegueta and absent in X. aethiopica. The mortality of C. maculatus increased gradually with exposure time and dosage of the plant powders. X. aethiopica caused 75.15% adult mortality and A. meleguta exerted 85% mortality at 120 hrs post infestation. Maximum oviposition deterrent activity was observed with X. aethiopica (54.26%) compared to A. melegueta (51.32%). Conclusively, both plants showed highly useful bioactivity against C. maculatus in suppressing oviposition and adult emergence and, therefore, can be used in formulating ecofriendly herbal insecticides. © 2015 Jordan Journal of Biological Sciences. Source

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