Insect Damage to Wind-Thrown and Standing Live Black Cherry Resulting From Delayed Salvage After a Major Abiotic Disturbance

Abstract

Severe windstorms that swept through three counties in northwestern Pennsylvania on July 21 and 22, 2003, caused extensive blowdown in many northern hardwood stands containing an extensive component of black cherry, Prunus serotina Ehrh. Although many species were affected by the storm, black cherry is the most valuable timber species in the region. A number of factors prevented salvage until 3 years after the storm. The purposes of this study were to identify the wood-boring insects that attacked damaged cherry and to estimate the value lost due to delayed salvage. The long-horned beetle Saperda imitans Felt and Joutel (Coleoptera: Cerambycidae) and the ambrosia beetle Xyleborinus saxeseni (Ratz.) (Coleoptera: Curculionidae: Scolytinae) were the most abundant wood borers reared from wind-thrown cherry. We also monitored both changes in the population of the bark beetle Phoeotribus liminaris (Ratz.) and the damage it caused to live residual cherry. Based on the average depth of S. imitans galleries and associated stain, the estimated grade loss of a 25-cm (10 in.) cherry log (large end) after slab removal was approximately 27% and for a 102-cm (40 in.) log it was 3.6%. Wood borer galleries occurred throughout the first 5.2 m (17 ft) of the butt log as well as in the upper bole and larger branches. The density of ambrosia beetle galleries on wind-thrown trees was highest on trees with dying and dead epicormics than on trees with live epicormics and higher on trees suspended off the ground. Catches of X. saxeseni in ethanol-baited, Lindgren funnel traps increased significantly from 2005 to 2006 as did numbers of P. liminaris and the gum spot damage these insects did to residual live cherry in 2005 compared with that in 2004. Results of this study indicate that the extent of insect damage after this abiotic disturbance was influenced by the time of year the damage occurred relative to the temporal activity of the insects involved and emphasizes the importance of swift salvage.