106 Vol. 42, No. 3: 106–111 Plant Protect. Sci. Insect pests may cause serious damage (80–100%) on field cowpea, Vigna unguiculata (L.) Walp., where modern pest control measures are absent. Currently, these measures rely heavily on synthetic insecticide application. The indiscriminate use of these chemicals has given rise to problems such as resistance of the pest species to insecticide (CHAMP & DYTE 1976; GEORGHION & LAGUNES- TEJEDA 1991), accumulation of toxic residues in food (SNEL SON 1987), health risks to the user and livestock, and environmental contamination. These problems have much increased the need for alternative, safe and effective biodegradable insecticides from natural sources with greater selectivity. The search for new types of insecti- cides and the re-evaluation and use of traditional botanical pest control agents thus seems to be a promising alternative. For many centuries, crude extracts from plants have been used by farmers to control insect pests on crops. Plant materials (powder, water extracts, oils and wood ash) contain complex mixtures of The Sensitivity of Flower Bud Thrips, Megalurothrips sjostedti Trybom (Thysanoptera: Thripidae) , on Cowpea to Three Concentrations and Spraying Schedules of Piper guineense Schum. & Thonn . Extracts ALPHONSUS MBONU OPARAEKE Department of Crop Protection, Institute for Agricultural Research, Faculty of Agriculture, Ahmadu Bello University, Nigeria Abstract OPARAEKE A.M. (2006): The sensitivity of flower bud thrips, Megalurothrips sjostedti Trybom (Thysanoptera: Thripidae) , on cowpea to three concentrations and spraying schedules of Piper guineense Schum. & Thonn. extracts. Plant Protect. Sci., 42: 106–111. The extracts of pods of West African black pepper, Piper guineense, at 5, 10 and 20% (w/v), were applied at two, four and six weekly schedules to control the legume flower bud thrips, Megalurothrips sjostedti on flowers of cowpea, Vigna unguiculata. The trials were conducted for 2 years under rain fed conditions in the northern Guinea savanna region of Nigeria. The results showed that the M. sjostedti population was significantly con- trolled on treated plots compared with the untreated check in both years. The extracts at the 20 and 10% rates and with six or four weekly applications significantly ( P < 0.05) reduced thrips pressure on cowpea flowers, were better than the 5% extract at all spraying schedules, and had the same efficacy as the synthetic insecticide treatment. Pod density per plant was significantly higher ( P < 0.05) on plots treated with the 20% extract at six or four weekly applications compared to other extract rates and was similar to that of the synthetic insecticide treatment. 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. Keywords: control of Megalurothrips sjostedti; extracts of Piper guineense; Vigna unguiculata; application schedules Partly supported by PEDUNE/PRONAF.