Inheritance of resistance in cowpea (Vigna unguiculata) to the pod-sucking bug Clavigralla tomentosicollis (Hemiptera: Coreidae) GO Olatunde 1 *, IA Biobaku 1 , DK Ojo 2 , OOR Pitan 1 and EA Adegbite 3 1 Department of Crop Protection, University of Agriculture, PMB 2240, Abeokuta, Nigeria. 2 Department of Plant Breeding and Seed Technology, University of Agriculture, Abeokuta, Nigeria. 3 Department of Biological Sciences, University of Agriculture, Abeokuta, Nigeria. *To whom correspondence should be addressed (dr_golat@yahoo.com) Abstract Inheritance of resistance in cowpea to Clavigralla tomentosicollis Stål was studied on F 1 , F 2 and F 3 generations produced from crosses made between Ife Brown, a susceptible cultivar (P S ), and TVu 3354, a resistant variety (P R ), on the pods of which freshly emerged nymphs of C. tomentosicollis were caged. Nymphal weight gain was significantly higher (p < 0.05) on P S . There were no significant differences between the weight gains of nymphs that fed on F 1 , F 2 and F 3 pods. Insect mortality was significantly higher on P R (86.7%) and the F 2 (70.0%) generation. Total nymphal development period was significantly longer on P R (15.0 days) while that on F 1 and F 2 generations was significantly longer than on the F 3 generation. Nymphal survival and adult emergence were observed on eight plants out of 60 and 19 plants out of 80 from the F 2 and F 3 generations, respectively. Broad-sense herita- bility estimates were 90.3% and 94.3% for the F 2 and F 3 generations, respectively. The results clearly indicated that TVu 3354 has highly heritable resistance to C. tomentosicollis. Copyright © 2008 John Wiley & Sons, Ltd Key words: Clavigralla tomentosicollis, cowpea, pod-sucking bug, resistance, Vigna unguiculata Introduction Cowpea, Vigna unguiculata L. (Walp.), is an important major food crop in many tropical countries, but yield levels in Africa are generally reported to be low. A notable feature of the cowpea crop is its susceptibility to damage by insect pests, and the low yields in Africa have been attributed mainly to severe insect pest infestation (Alghali 1992; Rusoke and Rubaihayo 1994; Edema and Adipala 1996). Numerous insect pests infesting the crop during all stages of growth and development have been described by Singh and Van Emden (1979) and Singh and Jackai (1985). Among these insect pests, the pod-sucking bug Clavigralla tomentosicollis Stål (Hemiptera: Coreidae) causes considerable economic losses on cowpeas (Singh and Jackai Tropical Science Trop. Sci. 2007, 47(3), 128–133 Published online 3 January 2008 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/ts.206