Use of UV-LED light to enhance establishment of Nesidiocoris tenuis for control of Bemisia tabaci infesting greenhouse tomato

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of greenhouse tomato and Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is an effective predator of this whitefly. Previously, we found that 385 nm LED lighting improved the predatory performance of N. tenuis on B. tabaci under laboratory conditions, ostensibly via mutual attraction of bugs and whiteflies to this wavelength, and improved aggregation of both insects around the light sources. Here we verified that LED lighting at 385 nm enhances the establishment of N. tenuis releases on tomato plants infested with B. tabaci under greenhouse conditions. In the first trial, conducted May-July, both whiteflies and predators were released three times; whitefly densities were not affected by LED lighting when predators were absent, but ended the experiment at lower densities when N. tenuis releases were combined with LED lighting than when they were not. In a second trial, conducted September-November under cooler conditions, a single whitefly release established an infestation and was followed by a single release of N. tenuis in two treatments, with and without LED. The LED lighting treatment maintained lower whitefly densities over a two month period in the crop, and higher densities of predators, than the predators-only treatment. Therefore, possible applications of short wavelength LED lighting to enhance N. tenuis augmentation programs in greenhouse settings appear worthy of further evaluation.N