Tobacco splitworm, budworm, and hornworm control with selected foliar insecticides
Tobacco splitworms (also known as potato tuberworms), Phthorimaea operculella, tobacco budworms, Heliothis virescens, and tobacco hornworms, Manduca sexta, are annual economic pests of tobacco and other row crops and vegetables throughout the southern USA. Insecticides play a key role in the management of these lepidopteran pests due to their general effectiveness and their relatively low costs. Tobacco splitworm larvae feed beneath the epicuticle layer of the leaf tissue, and are thus not directly exposed to the foliar insecticide spray particles. Tobacco budworms also are somewhat protected from direct insecticide exposure due to their feeding behavior within or near the terminal bud. This study was designed to evaluate numerous insecticide treatments in 2007-2009 for the control of splitworms, budworms and hornworms. Results indicate that Coragen insecticide (rynoxypyr) applied as either a foliar spray or as a transplant water treatment reduced the incidence of splitworm tunneling in tobacco leaves. Foliar applications of Brigade (bifenthrin) and Warrior (l-cyhalothrin) also were effective. Although data are limited (2009 only), it appears that foliar sprays of Durivo (chlorantraniliprole + thiamethoxam), Steward (indoxacarb), Rimon (novaluron), Voliam Flexi (chlorantraniliprole + thiamethoxam), Voliam ExPress (chlorantraniliprole + lcyhalothrin) and HGW86 (cyazypyr) also suppress splitworm damage in tobacco. Budworms were effectively controlled with foliar applications of Coragen, Steward, Voliam Flexi, Voliam ExPress, Durivo, Belt (flubendiamide), Tracer (spinosad), Denim (emamectin benzoate), and HGW86. Fair control of budworms was obtained with Brigade, Warrior, and Rimon, at the rates examined. Tobacco hornworms were effectively controlled with every foliar insecticide treatment evaluated. It appears that several new insecticide products will be available for tobacco production in the USA in coming years.