Engelmann Spruce Cone Losses Caused by Insects in Northern Utah in a Year of Low Cone Production
Great Basin Naturalist
The impacts and timing of insect infestation were determined in developing Engelmann spruce cones throughout the summer of a year of low cone production in northern Utah. The major insects found were the western spruce budworm, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae); fir coneworm, Dioryctria abietivorella Grote (Lepidoptera: Pyralidae); and the spruce seed moth, Laseyresia youngana Kearfott (Lepidoptera: Olethreutidae). Insects reduced the survival of cones to 11.48 cones out of 100. The high percentage of seeds and cones lost to insect predation supported previous studies of a similar nature.
Cameron, D.E. and M.J. Jenkins (1989). Engelmann spruce cone losses caused by insects in Northern Utah in a year of low cone production. Great Basin Natur. 48(4): 508-511.