Impact of Nectariless Cotton on Plant Bugs and Natural Enemies

Removal of extrafloral nectaries from cotton plants reduced populations of the cotton fleahopper, Pseudatomoscelis seriatus (Reuter) and the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) ca. 60% Total populations of natural enemies were also reduced by the nectariless plant; reductions ranged from 17–35%. Significant effects were found with Chrysopa carnea Steuens (4 locations), Orius insidiosus (Say) (2 locations), Coleomegilla maculata (De Geer) (one location), Hippodamia convergens Guerin-Meneville (2 locations), Spanagonicus albofasciatus (Reuter) (one location), Nabis spp. (one location) and a tachinid fly (one location). Laboratory experiments with tarnished plant bugs indicate a 92% reduction in oviposition on nectariless cotton plants.