ABSTRACT

The major biotic constraints faced in guava cultivation was the presence of insect pests, mainly the sucking pests and fruit fly. To address this problem, a roving survey was carried out during July- December, 2023 in major guava growing areas of Dharwad and Gadag districts of Karnataka. The highest infestation of all the insect pests (sucking pests and fruit fly) was recorded in Gadag district compared to Dharwad district except for tea mosquito bug, incidence of which was less in Gadag district. Further population of different predators was also recorded.
Population dynamics of major insect pests of guava revealed that, the highest infestation of sucking pests such as tea mosquito bug, mealybug and spiralling whitefly was recorded during the second fortnight of October. Further, the highest incidence of fruit fly was noticed during September first fortnight. The peak population of natural predators such as coccinellids, reduviids and spiders was occurred in second fortnight of October. The correlation analysis showed that, all the sucking pests except tea mosquito bug and predators had significantly negative correlation with relative humidity and rainfall, but a non- significant positive correlation with the minimum temperature and significantly positive with the maximum temperature. Conversly, tea mosquito bug showed a significant negative correlation with the maximum temperature but positive correlation with the minimum temperature, relative humidity and rainfall.
Among the various insecticides tested against the sucking pests, soapnut powder spray followed by Beta-cyfluthrin 8.49 % + Imidacloprid 19.81 % OD and detergent powder spray followed by Beta-cyfluthrin 8.49 % + Imidacloprid 19.81 % OD was found effective in reducing sucking pests incidence.