Effectiveness of an integrated pest management program for Bemisia tabaci (Gennadius) with Nesidiocoris tenuis (Reuter) in greenhouse tomatoes

Abstract

We evaluated the effectiveness of an integrated pest management (IPM) program combining the predatory bug Nesidiocoris tenuis, verbena (Verbena × hybrida ‘Tapien’) as an insectary plant for N. tenuis, and a selective insecticide to control Bemisia tabaci in experimental greenhouse tomatoes. Testing was conducted from March to July 2015. We assigned three treatments to different sections of a tomato greenhouse: i) IPM treatment (N. tenuis + verbena + selective insecticide), ii) chemical treatment (insecticides only), and iii) control. The control treatment was intended to be grown without insecticides or N. tenuis, but we sprayed insecticide once because of heavy infestation of B. tabaci in mid-June. In the IPM treatment and the chemical treatment, the density of B. tabaci adults from late May to mid-June and the density of nymphs in June and July were significantly lower than in the control treatment. There was no significant difference in the density of B. tabaci between the IPM treatment and the chemical treatment throughout most of the growing period. Although N. tenuis populations became established and increased on both tomato and verbena, the density of N. tenuis adults on verbena was always low, suggesting that N. tenuis adults moved from verbena to tomato. No significant differences in the infection rate for Tomato yellow leaf curl virus (TYLCV) were observed among treatments. There were no significant differences in the number of fruits per truss among treatments, indicating that the plant-feeding behavior of N. tenuis did not affect tomato fruit production. Moreover, there were five insecticide applications in the chemical treatment but only one in the IPM treatment. These results indicate that an IPM program combining N. tenuis, verbena, and selective insecticides is a promising alternative to chemical control of B. tabaci in greenhouse tomato crops.