Evaluation of biological and biorational control tactics for suppression of Nantucket pine tip moth damage in Virginia pine Christmas trees.

A study was performed to evaluate the potential of the egg parasitoid Trichogramma exiguum Pinto and Platner (Hymenoptera: Trichogrammatidae), the newly registered insect growth regulator (IGR) tebufenozide (Confirm), and a modified spray technique (top whorl only pesticide application) for suppression of Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), damage in Virginia pine, Pinus virginiana Mill., Christmas trees. Augmentative releases of T. exiguum failed to increase parasitism levels in release plots compared with controls, and significant reduction in tip moth damage did not occur. High predation levels on released T. exiguum may have contributed to the failure of parasitoid augmentations. Whole-tree and top whorl tebufenozide treatments provided significantly greater damage control than corresponding applications of acephate (Orthene), a commonly used pesticide in Christmas trees. Damage to trees receiving whole-tree chemical applications did not differ significantly from trees receiving top whorl treatments for most measurements of damage. Top whorl chemical treatments resulted in a 67% reduction in time required for application and a 70% reduction in pesticide used.