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.

In the present study, experiments were carried out in French bean fields over two planting periods to evaluate the potential use of sticky traps for monitoring the populations of pest thrips. To this end, blue, yellow and clear sticky traps (with and without a thrips lure, i.e. Lurem-TR) were tested. Field observations on thrips catches were made at weekly intervals from the sticky traps, and absolute estimates of thrips populations and their natural enemies were made by destructive (picking leaves and flowers) and non-destructive sampling (plant tapping) of plants until crop senescence during the two planting periods. Blue traps caught two and three times more thrips compared with yellow traps over the first and second planting periods, respectively. Blue traps were more attractive to Megalurothrips sjostedti (Trybom), Frankliniella schultzei (Trybom) and Frankliniella occidentalis (Pergande), while yellow traps were only attractive to Hydatothrips adolfifriderici (Karny) and the natural enemies of thrips. The addition of Lurem-TR to the sticky traps significantly increased the capture of all thrips species, but not their natural enemies. The estimates of thrips populations from blue sticky traps with Lurem-TR were found to be highly correlated (r= 0.95; P< 0.001) with the absolute estimates of thrips using the destructive sampling method. The results demonstrate that blue sticky traps and Lurem-TR can be an efficient tool for the monitoring of thrips populations on French beans with least influence on their natural enemies.