Seasonal incidence of pod bugs and their natural enemies in vegetable cowpea ecosystems of Kerala

Studies were undertaken at the College of Agriculture, Vellayani, Thiruvananthapuram, S. India during 2005–2006 to assess the seasonal incidence of pod sucking bugs infesting vegetable cowpea and their natural enemies. The nymphal and adult population of the pentatomid stink bug, Nezara viridula (L.) attained peak values during May 2006 and the first fortnight of April 2006, respectively. The nymphal population of the alydid pod bugs, Riptortus pedestris F. and Riptortus ? linearis (F.) was significantly higher during the first fortnight of May 2006 and the succeeding three fortnights. Adult population of R. pedestris and R? linearis peaked significantly during the first and second fortnights of June 2006 respectively, when compared to most other periods of the year. Minumum temperature was positively correlated with the population of nymphs of Riptortus spp., adult R. pedestris and adult N. viridula. Preying mantids and spiders were also documented in the cowpea ecosystem.