Effectiveness of light traps with different wavelength in catching harmful and beneficial insect fauna in greenhouse tomato growing

A two-year field study was conducted to determine the effectiveness of light traps with different wavelengths in capturing harmful and beneficial insect fauna in greenhouse tomato cultivation. In both years (2020 and 2021), experiments were conducted in 2 separate greenhouses of approximately 1 decare each in Antalya (Elmalı) province. In both years, 9 specially designed light traps were placed in the study greenhouses, 3 m from the edges of the greenhouse, with 3 m between each trap and 20 cm from the growing end of the plants. During weekly trap checks in the light traps in both greenhouses, the total number of adult T. absoluta caught in each trap was recorded. In addition, weekly counts of some other important pests [Cutworms (Agrotis spp.) and Cotton bollworm (Helicoverpa armigera (Hübner)) (Lepidoptera: Noctuidae)] and some beneficial insects [(Bombus sp. (L.) (Hymenoptera: Apidae) and Chrysoperla carnea Stephen (Neuroptera: Chrysopidae)] caught in the traps were recorded. As a result of the studies, the highest number of T. absoluta adults (female + male) were caught in the 20W CFL Sylvania 365 nm (UV-A) light trap, at a rate of 51.3% in both greenhouses in the first year's trial, and 52.0% and 53.0% in the second year's trial. This was followed by the 13W E27 Sylvania 368 nm (UV-A) light trap, which captured 26.6% and 25.9% in the first year and 33.0% in the second year in both greenhouses. It is predicted that this wavelength of light can be used to manage T. absoluta populations. It is envisaged that using a 20W CFL Sylvania 365 nm (UV-A) light trap in areas where Cutworms (Agrotis sp.) pest causes intense damage can reduce the density of this pest and reduce the number of chemical applications to be applied. It was observed that the 20W CFL Sylvania 365 nm (UV-A), 13W E27 Sylvania 368 nm (UV-A) and 9W BLB (Black Light) light traps, which had the highest number of bollworm capture rates, formed a separate group from the other traps. A more comprehensive study on this subject needs to be carried out and the wavelength of light to which the most Cotton bollworm (H. armigera) adults are oriented should be determined. It was determined that the total number of beneficial insects caught in all traps during the experiment did not exceed 5 Bumblebees and 41 C. carnea adults. Accordingly, if the light traps used in the study are applied to pests in greenhouses, beneficial Bombus sp. and it is predicted that it will not pose a threat to C. carnea.