Evaluación de la fitofagia de Tupiocoris cucurbitaceus (Spinola) (Hemiptera: Miridae) en el cultivo de tomate

In Uruguay, tomato (Solanum lycopersicum L.) is one of the main horticultural products in terms of its volume of supply and economic importance. The main pest of protected tomato crops is the greenhouse whitefly (Trialeurodes vaporariorum), which can affect the cosmetic quality of the fruits and cause yield losses. In Uruguay and countries in the region, Tupiocoris cucurbitaceus (Spinola) is commercially available, a native mirid that feeds on whiteflies and other pest arthropods. Several species of mirids have been successfully used for biological pest control in Europe for more than 20 years. Mirids have a zoophytophagous feeding habit; it has been reported that under certain conditions phytophagy can affect tomato crops. The objective of this work was to evaluate the phytophagy of T. cucurbitaceus in tomato crop under controlled conditions. Plant damage was assessed by confining a tomato plant exposed to 20 nymphs or 20 adults of the predator for 72 hours without food supplementation. Control treatments without nymphs and without adults were included. At 0, 3, 6 and 20 days after the predator was removed, the feeding marks on the plant, their location on the different leaves and the height of the plants were recorded. Phytophagy in fruits was evaluated by exposing a tomato fruit for 48 hours to 4 nymphs or 4 adults of the predator and two control treatments without the presence of the predator. Feeding punctures were recorded in the fruits and calyx of tomato at 0, 3, 6 and 20 days after the mirid was eliminated. The results indicated that both nymphs and adults of T. cucurbitaceus caused feeding marks on the tomato plant described as small punctures found mainly in the lower and middle strata of the plant. Tomato plants exposed to adults of the predator were significantly shorter than the control treatment without the presence of adults for all the dates evaluated. While the nymphs caused a reduction in the height of the tomato plants only 6 days after elimination compared to the control without nymphs. Despite finding feeding marks on the calyx and tomato fruits exposed to nymphs and adults of the predator, these did not affect the cosmetic quality of the fruits.