Sustainable management practices for tea mosquito bug Helopeltis antonii Signoret (Miridae:Hemiptera) on cashew

摘要

Studies on exploitation of natural enemies and their role in suppression of Tea mosquito bug Helopeltis antonii Signoret were carried out in the cashew plantations of Zonal Agricultural Research Station, Brahmavar and Pethri village, Udupi district and in maidan tracts of Chintamani, Karnataka during 2006-08. Telenomus species was found to be the predominant egg parasitoid on TMB. Maximum egg parasitisation of 16.80, 15.35 and 12.70 per cent was recorded on TMB eggs in Brahmavar, Pethri and Chintamani cashew plantations, respectively, in December.The ant, Oecophylla smaragdina Fabricius was the most effective predator against TMB. Cashew trees fully colonized by O. smaragdina received least TMB damage of 11.40 + 1.87 and 8.71 + 1.23% during 2006-08 in coastal and maidan Karnataka, respectively. TMB damage colonized with O. smaragdina were 23.40 + 2.16 in coastal and 20.12 + 2.05 in maidan part. The unsprayed cashew trees with no ant recorded maximum damage of 47.42 + 3.71 and 52.36 + 3.86% in coastal and maidan tracts, respectively. Higher nut yield of 3.70 kg/tree in coastal and 2.43 kg /tree in maidan tract was recorded from the trees fully colonized with O.smaragdina. The sequential sprays of monocrotophos (0.05%) - ??-cyhalothrin (0.005%) - carbaryl (0.10%) registered the least per cent TMB damage, higher nut yield and high C:B ratio.