Evaluation of coloured traps with kairomone attractant for monitoring thrips population dynamics on tomato crop in East Africa

Tomato is an important vegetable crop that is cultivated for the domestic market in Kenya and other East African countries. Thrips are one of the key pests hampering the production of tomato, both by direct damage to the crop and as vectors of tospoviruses. Field experiments were carried out over two planting times to evaluate the use of sticky traps for monitoring thrips infesting tomato in East Africa. Blue, yellow, and clear sticky traps with and without a thrips lure (Lurem-TR) were tested. Field observations for thrips catches on the sticky traps were made weekly until crop senescence. Sticky traps were replaced with new ones at each observation time. Additionally, both destructive and non-destructive samplings for thrips were done at each observation. Frankliniella schultzei (Trybom) and Ceratothripoides brunneus (Bagnall) were more attracted to blue than yellow traps. Frankliniella occidentalis (Pergande) attraction to blue and yellow traps was not distinctive. The addition of Lurem-TR on traps increased captures of F. schultzei and F. occidentalis but not of C. brunneus . Blue traps with Lurem-TR captures had the highest correlation with absolute estimate of thrips density on the plants. Rainfall had significant negative correlation with thrips population on the crops. Our results show that blue traps and Lurem-TR have strong potential for improving monitoring and management of thrips on tomato.