Insect Pest Complex of Cashew and Influence of Biotic and Abiotic Factors on the Incidence of Cashew Pests in Maidan Parts of Karnataka

摘要

Productivity of cashew (Anacardium occidentale L.) in India is influenced by many biotic and abiotic factors, of which pest damage is one of the main constraints. Tea mosquito bug (TMB), Helopeltis antonii Sign, and cashew stem and root borer (CSRB),Plocaederus ferrugineus L. are the two major pests and the minor pests occur with a regional specificity. Hence the study was taken to ascertain the insect pests infecting cashew, their period of occurrence, pest status and natural enemy complex. Cashewplantations of AICRP, Chintamani and cashew fields of farmers in maidan parts of Karnataka were chosen for the survey. During the course of survey, 37 species of insect pests inflicting mild to severe injury to the cashew crop were noticed. The TMB and CSRB, were the most notorious pests of cashew in maidan parts of Karnataka. During the survey, 3 species of spiders, 1 species of reduviid bug and 1 species of preying mantis were found feeding on different stages of TMB. Aphids were predated by coccinellids, syrphids, brown and green lacewing. The maximum temperature (0.239) and sunshine hours (0.516) had a positive relation with the activity of TMB, but negative correlation was established with morning and evening relative humidity (-0.327 and -0.402)and rainfall (-0.369). The activity of CSRB was observed throughout the year but its activity was low during December and January months. Maximum temperature had positive correlation (0.721) with the incidence of the pest.