Pests and predators activity on new variety of dolichos bean [Lablab purpureus (L.) Sweet].

SUMMARY A study was carried out to investigate the incidence of different insect pests and predators on new variety, HA -4 of dolichos bean. The results of the field study revealed that 15 insect pests belonging to nine different families of five orders and five species of predators belonging to five different families coming under four orders. The sucking pest population was found throughout the year. The peak population of aphids (49.00/3 leaves), pentatomid (5.20/5 plants) and coreid bugs (11.20/5 plants) were observed on 60 days after sowing (DAS). Whereas, eurybrachid bugs (5.20/5 plants) recorded at 50 DAS. Among the pod borer complex, higher pod damage due to Helicoverpa armigera, Maruca vitrata and Lampides boeticus was 20.43, 16.66 and 10.20 per cent pod damage, respectively on 80 DAS, whereas, Callosobruchus theobromae (12.55 %) was observed on 90 DAS. The important predator’s viz., robber fly, coccinellids, syrphids, green lacewing and dragonfly were prominent ones. The activity of predators was high between 40 and 60 DAS and population decline was observed thereafter.