MIRID BUGS AS BIOLOGICAL CONTROL AGENTS IN PROTECTED TOMATO CROPS IN THE OESTE REGION
The whitefly Trialeurodes vaporariorum is a key pest of greenhouse tomato crops in the Portuguese Oeste region. Mirids, tiger-fly and parasitoids are important biological control agents for this pest. Mirids are generalist predators and they control also the leafminers Liriomyza spp., and more recently the tomato leaf miner moth, Tuta absoluta. Preliminary studies to evaluate the impact of these predators were made on tomato crops in two commercial greenhouses during two years. Biological control had already been adopted for three years in one of these greenhouses (Greenhouse 1). In the other greenhouse (Greenhouse 2) biological control was initiated in the first year of this study. In both cases biological control consisted on augmentation of the autochthonous populations of natural enemies and improving them through augmentative releases whenever necessary. In the first year, differences among greenhouses regarding whitefly, sooty mould and mirids incidence were observed. For this pest, either chemical or biological treatments with mirids were not needed in Greenhouse 1. However, in Greenhouse 2 Macrolophus caliginosus was released for the control of whiteflies but it did not succeed due to the insecticides used for thrips control. Re-colonization by authoctonous Dicyphus cerastii was later observed in Greenhouse 2. In the second year, mirids population increased in Greenhouse 2 and at the end of the winter-spring crop mirid populations were already similar in size in both greenhouses. Whitefly and sooty mould incidences were also similar. In this crop M. caliginosus and D. cerastii were dominant in Greenhouse 1 and Greenhouse 2, respectively, but in the summer-autumn crop M. caliginosus and D. cerastii in the beginning and Nesidiocoris tenuis at the end were the dominant species in both greenhouses.
Figueiredo, E., Prieto, R., Mexia, A., Rodrigues, S., Costa, C.A. and Godinho, M.C. (2012). MIRID BUGS AS BIOLOGICAL CONTROL AGENTS IN PROTECTED TOMATO CROPS IN THE OESTE REGION. Acta Hortic. 927, 253-259
conservation biological control, whiteflies, Trialeurodes vaporariorum