Seasonal Incidence and Management of Tea Mosquito Bug, Helopeltis spp. Infesting Guava in Southern Karnataka, India

Seasonal incidence and management of tea mosquito bug (TMB), Helopeltis spp. infesting guava was studied at College of Sericulture, Chintamani, during 2023-2024. To study the seasonal incidence, observations were recorded at fortnightly intervals on various parts of the plant. TMB were observed infesting young leaves of guava plants during the first fortnight of July. The infestation continued throughout the second fortnight of December, affecting both young leaves and fruits. The population then declined and completely disappeared from January onwards. The pest population reached its peak during September 2023, with a per cent damage of 15.10 per cent on leaves and 17.11 per cent on guava fruits, with an average population of 3.95 bugs per five sweeps. The correlation studies revealed that the maximum temperature was negatively correlated, but minimum temperature, morning and evening relative humidity was positively correlated, whereas, total rainfall was significantly positively correlated with the incidence of the tea mosquito bug. To evaluate the efficacy of novel insecticides against the guava tea mosquito bug, Helopeltis spp. It is evidenced that fipronil 5% SC, which was significantly superior compared to the rest of the treatments, with per cent reduction of 76.36% and 78.45% (leaves and fruits). Lambdacyhalothrin 5% EC, Imidacloprid 17.8% SL were next best treatments, followed by moderate efficacy observed with thiamethoxam 25% WG and buprofezin 25% SC. Beauveria bassiana (2 × 108 cfu/g) and Lecanicillium lecanii (2 × 108 cfu/g) showed comparable statistical performance. However, azadirachtin 10000 ppm proved to be the least effective in controlling TMB incidence. A similar pattern was observed during the second spray.