Tea-mosquito bug (TMB), Helopeltis antonii Sign. Is an important pest of cashew which is one of the reasons attributed to the drastic decline in cashew production with the yield loss upto 40 to 50 per cent and in some situations up to 100 per cent? In the present study, effect of Tea-mosquito bug damage on yield and yield attributing characters viz, flushs and panicle of cashew were studied by selecting 25 cashew genotypes from the core population of 64 germplasm accession at Agricultural and Horticultural Research Station, Ullal. The tree canopy extended more in East-west side compared to North-South side and Tea-mosquito bug damage was recorded higher in western side compared to southern side of the trees. The yield of cashew trees 10-15 per cent and damage by 85-100 per cent with respect to age of the trees. The late harvest varieties are less damage compared to early harvest varieties. It is revealed from the present study that, Ullal-1, Ullal-2, UN-50, Vengurla-4 and V.R.I.-3 are showing better resistance to Tea Mosquito bug damage in coastal Karnataka.