Managing tea mosquito bug (Helopeltis antonii Sign.) in cashew by augumenting red ants Oecophylla smaragdina (F.)

Sreekumar, K.M.; Vasavan, N.; Madhu, S; Sijila, J.; Sreedharan, M.P.; Sreelekha, S.; Cheriyan, Tom

Managing tea mosquito bug (Helopeltis antonii Sign.) in cashew by augumenting red ants Oecophylla smaragdina (F.)

2011

An experiment was undertaken to manage tea mosquito bug (Helopeltis antonii) in cashew through augumentative use of red ants (Oecophylla smaragdina). Fifty per cent of the 190 plants in an orchard were colonized with red ants. Pest population, extent of damage and yield parameters were recorded for three years for both treated and untreated plants, coinciding with flushing, flowering and fruiting phases of the crop. Bug population was significantly lower in plants colonized by red ants. The mean population values varied from 1.61 to 9.76 for untreated plants and 0 to 0.07 for treated plants. The extent of damage in untreated plants varied from 20.45 to 92.9 per cent, whereas the same was a negligible 0.02 to 0.009 per cent in treated plants. The mean number of immature nuts was significantly higher in treated plants as compared to untreated plants. The average yield recorded from red ant free trees varied from 0.39 kg to 3.85 kg per tree while that of plants colonized by red ants were significantly higher at 5.01 to 15.75 kg. Further, production period was also extended by two months in the latter, compared to untreated plants. Thus, the net effect of colonization by ants was an increase in yield by 400 per cent by the third year of the study. The cost benefit ratio worked out indicates that the red ant technology is economically more viable than chemical pesticides.

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