Efficacy of wing versus delta traps for predicting infestation levels of four generations of the nantucket pine tip moth (Lepidoptera: Tortricidae) in the southern United States

Abstract

The use of pheromone trap catches to reliably predict damage by the Nantucket pine tip moth, Rhyacionia frustrana (Comstock), in loblolly pine (Pinus taeda L.) plantations would provide forest managers with a valuable integrated pest management tool. At 17 sites throughout four states in the southern United States, in areas where R. frustrana has four annual generations, adult moths were monitored throughout the year (2002) using two types of pheromone traps, and subsequent infestation levels were determined for each tip moth generation. Cumulative wing trap catch tallies up to published spray dates for three of four adult emergence periods were highly predictive of top whorl damage during the subsequent generation using linear regression models. Multiple linear regression that included initial average tree height as a covariate did not significantly improve model efficacy. Cumulative delta trap catch tallies up to the spray date were not predictive of subsequent damage levels for any tip moth generation using linear regression models. Although multiple linear regression incorporating tree height as a covariate did greatly improve delta trap model efficacy, the power and significance of these models remained insufficient. Wing traps seem to be much more sensitive to tip moth population change than delta traps; however, both are useful for monitoring seasonal activity and initiation of spray timing models.