Sources of resistance to the common cowpea pod sucking bugs Riptortus dentipes (Fabricius) and Anoplocnemis curvipes (Fabricius) in cowpea Vigna unguiculata (L.) Walp
The successful preliminary field evaluation in Kenya of 4022 cultivars of Vigna unguiculata from around the world revealed that >99% of them were susceptible to damage caused by the coreids Riptortus dentipes and Anoplocnemis curvipes when rated on a 1-5 scale based on the degree of pod shrivel. Thirty-three cultivars which sustained 20-39% pod damage were considered moderately resistant to the coreids and were selected for further field tests. Of these, 8 exhibited reasonably high levels of resistance: Emma B (22.5% pod damage), Vita-4 (19.8%), PS-1 (36.7%), PS-2 (33.2%), Katumani-1 (22.2%), Tvu no. 6641 (35.8%), Tvu no. 4052 (21.8%) and Tvu no. 4539 (22.2%). Further field tests indicated that growth characters such as colour of the fresh pods, external pod morphology, thickness of the pod walls, peduncle length and position of the pod in relation to the canopy contributed to the resistance of the cowpeas to the coreids.