Field survey and comparative biology of tea mosquito bug (Helopeltis spp.) on cashew (Anacardium occidentale Linn.)

Abstract

Cashew (Anacardium occidentale Linn.) has become a very important tree crop in India. Several insect pests, however, have been recorded on cashew and prominent among which is the tea mosquito bug (TMB), Helopeltis spp. (Hemiptera: Miridae). Field survey from November 2009 to November 2011 suggests that Helopeltis antonii was dominant, which accounted for 82% of all Helopeltis spp. collected; whereas, Helopeltis bradyi and Helopeltis theivora accounted for 12 and 6%, respectively. No significant differences in egg hatchability percentage among the three species were observed. The study showed that there is significant variation in developmental rate of 2nd, 3rd and 4th instar nymphs of Helopeltis spp. The total developmental time for H. antonii, H. bradyi and H. theivora were 224.19, 211.38 and 214.59 hours, respectively. Survival rates of the nymphal instars of H. antonii were significantly high compared to H. bradyi and H. theivora. The sex ratio of H. antonii was highly female biased. The adults of H. bradyi and H.theivora survived longer and produced significantly higher number of eggs than H. antonii. The outcome of this study is very important in planning control as insect monitoring and biological studies are important components of Integrated Pest Management (IPM).