Colonization preferences of the European woodwasp, Sirex noctilio, on southeastern pine species

We assessed the colonization and oviposition preferences of an exotic woodwasp species, Sirex noctilio Fabricius, in 2010 on six southeastern pine species. Specifically, we focused on loblolly, shortleaf, slash, longleaf, eastern white, and Virginia pine with Scots pine as a control species. We conducted host choice and no-choice experiments on S. noctilio, and determined attributes (wood and resin properties) of the southeastern tree species to provide mechanisms for insect colonization preferences. Preliminary results indicates that greater numbers of adult females of S. noctilio were drilling with their ovipositor on Scots, white and Virginia pines followed by longleaf and shortleaf pines with loblolly and slash pines at the lowest levels. More females of S. noctilio were found resting on white and Virginia pines followed by Scots, slash, and longleaf in decreasing numbers. The adults of S. noctilio started emerging in less than five months indicating that diapause may not be facultative for this species. In spring 2011, we dissected these logs to collect data on the reproductive success of S. noctilio, and to also measure adult characteristics of parental and progeny generation from 2010. Similar to colonization data, greatest emergence of progeny was from Scots, white, and Virginia pines. Our overall goal is to incorporate these biological data for S. noctilio in the existing risk maps for better predictability about which areas are most susceptible to invasion by S. noctilio, and where to focus our survey and management efforts for the southeastern U.S. region.