Wild Pigs: inciting factor in southern pine decline?

Abstract

During an investigation into southern pine decline at Fort Benning Georgia, the possibility of wild pigs (Sus scrofa) as an inciting factor became evident. Their rooting activity caused significant root damage on sites showing symptoms of pine decline. It was thought that perhaps the pigs may be moving around pathogenic fungi during their rooting activity in Pinus taeda (loblolly pine) stands. In 2008 and 2010, fungal isolates were obtained from the snouts of wild pigs captured from these stands, as well as, from root-feeding bark beetles and roots sampled 2003-2005. Micromorphology and DNA sequences of the ITS, elongation factor, and beta-tubulin gene regions were employed to identify the fungi recovered. Two new Ophiostoma species and a new Leptographium species were recovered. This study shows that wild pigs may exacerbate pine decline in this location by predisposing trees to bark beetles by reducing tree vigor when causing wounds for soil-borne or insect vectored pathogen infection and perhaps incidentally vectoring plant or tree pathogens during rooting activity.