The native North American wood wasp, Sirex nigricornis F., has received significant attention over the last several years due to the introduction and successful establishment of the European wood wasp, S. noctilio L. in eastern North America. Larval size and development of S. nigricornis are important variables that can help to compare demography of the two species and predict future interactions. We measured head capsule width, body length, and weight of S. nigricornis larvae removed from 14 pine trees, felled across the Ozark and Ouachita National Forests of Arkansas in 2012. We also recorded the height at which larvae were removed, and the diameter of the stem at that height. We used logistic regression to compare proportions of larvae removed from each section of each tree. Two-thirds of the larvae collected came from a single tree. Most larvae were in the lower and middle sections of trees and larval size was positively correlated with tree diameter. Ophiostomatoid fungi were absent in trees that produced the highest number of larvae, implying S. nigricornis colonized those trees before bark beetles. These results have implications for interspecific competition and interactions among S. nigricornis and S. noctilio, and for management which relies on successful larval development to transmit parasitic nematodes.
Hartshorn, Jess; Galligan, Larry D.; and Stephen, Fred
"Sirex nigricornis (Hymenoptera: Siricidae) larval development correlated with tree characteristics and ophiostomoid fungal infection,"
The Great Lakes Entomologist, vol 53
Available at: https://scholar.valpo.edu/tgle/vol53/iss2/11