BIOLOGY AND LIFE HISTORY OF EPURAEA OBLIQUUS HATCH (COLEOPTERA: NITIDULIDAE) ON WESTERN GALL RUST

Abstract

AbstractThe life cycle, phenology, and abundance of Epuraea obliquus Hatch was studied near Hinton, Alberta. Most of the life cycle occurs on galls of Endocronartium harknessii (J.P. Moore) Y. Hiratsuka (western gall rust) infecting lodgepole pine (Pinus contorta Dougl. var latifolia Engelm.). Both adults and larvae feed on the spores of the fungus. Individuals of this beetle were found on most galls sampled. Adults overwinter in the soil. They emerge in the spring to seek out and colonize galls. Eggs are laid on the surface of galls, mainly under the periderm, and larvae feed on the fungus, developing through three larval instars. Larvae in the last instar drop from galls to pupate in the soil. Adults leave the soil in late summer and return to feed on inactive galls before overwintering in the soil. The phenology of E. obliquus is closely synchronized with the timing of rust sporulation and the impact of beetle feeding may be an important natural control of western gall rust.