Fettig, C.J., Dabney, C.P., McKelvey, S.R., and Huber, D.P.W. 2008. Nonhost angiosperm volatiles and verbenone protect individual ponderosa pines from attack by western pine beetle and red turpentine beetle (Coleoptera: Curculionidae, Scolytinae). Western Journal of Applied Forestry 23:40 – 45. LINK