Larvae of Psyrassa unicolor (Randall) tunneled basally in 2- to 4-mm-diameter pecan twigs for distances of 12 to 36 cm until intersecting a larger branch, which they girdled. Branches 10 to 50 mm in diameter and 0.6 to 3.6 m long were severed with a smooth concentric cut, and they fell from late January through May. Twenty-nine percent of the larvae were in the severed portion of the branch, 13% were in the branch stub, and the remaining larvae were dislodged and lost during the break. Branches pruned by P. unicolor were distinguished from those pruned by other species by the kind of girdle, time of year, and size of pruned branches.
Author notes
1Entomologist, Southern Hardwoods Laboratory, maintained by the Southern Forest Experiment Station, Forest Service, USDA, in cooperation with the Mississippi Agricultural and Forestry Experiment Station and the Southern Hardwood Forest Research Group.
