Tobacco splitworm Phthorimaea operculella (Lepidoptera: Gelechiidae) damage and control on flue-cured tobacco Nicotiana tabaccum

Splitworm populations have become an increasing pest problem in NC tobacco fields. The larvae are leaf miners, reducing the weight and quality of tobacco harvested. Large populations can destroy leaves and plants. Treatment in the past for splitworms has been unreliable at best, ocassionally resulting in season-long outbreaks. While damage and control data analyses are incomplete, results from field studies we have conducted over the last three growing seasons indicate a correlation between tobacco weight and the number of splitworms present in the plant. It appears that a light infestation actually raises tobacco weight, while heavier infestations cause significant weight loss. Heavier infestations also significantly decrease the quality of the leaf, causing substantial reductions in value. In chemical trials, Novaluron, along with Acetamiprid and Rynaxypyr, have shown remarkable control of splitworm larvae both upon contact and after the larvae have infested the leaf.