Ponderosa pine conelets in 10 stands on the Coconino and Kaibab national forests were observed periodically from July 1982 until they matured in September 1983. Abortion, ponderosa pine cone beetles (Conophthorus ponderosae Hopkins), and ponderosa pine coneworms (Dioryctria sp., probably Auranticella [Grote]) were the significant mortality factors. Cattle, tip moths, and squirrels rarely destroyed conelets or cones.
Schmid, J. M.; Mitchell, J. C.; and Mata, S. A.
"Ponderosa pine conelet and cone mortality in central Arizona,"
Great Basin Naturalist: Vol. 46
, Article 9.
Available at: http://scholarsarchive.byu.edu/gbn/vol46/iss3/9