author(s)
Shivaji Hausrao Thube, RTP Pandian, Gagana Kumar Mahapatro, Robin Gogoi, Najeeb Naduthodi and Bhavishya

abstract
The present investigation was conducted to study the lethal effect of insecticides recommended for management of tea mosquito bug, Helopeltis spp. on bio-control agent, Trichoderma harzianum. Effect of six insecticides (Bifenthrin 10% EC, Clothianidin 50% WDG, Flonicamid 50% WG, Imidacloprid 17.8% SL, Thiamethoxam 25% WG and Quinalphos 25% EC) with three doses (lower, recommended and higher) on colony growth, antagonism potential and sporulation of Trichoderma harzianum were studied. Quinalphos 25% EC showed high inhibitory effect in all three doses. Recommended dose of Quinalphos caused 72.77, 58.18 and 97.16 per cent reduction in mean colony growth, antagonism potential and sporulation of Trichoderma harzianum respectively. Slight deleterious effect in highest dose (150 ppm) of Bifenthrin 10% EC was recorded with 13.33, 5 and 9.83 percent inhibition in mean colony growth, antagonism potential and sporulation respectively. All other insecticides under investigation were found non toxic at all three doses and were at par with control which indicated the compatibility of these insecticides with Trichoderma harzianum. All the compatible insecticides can be utilized in Integrated Pest Management programme with recommended doses along with Trichoderma harzianum without causing any deleterious effect.