Aspen Bibliography

Minnesota Forest Insect and Disease Survey for 1941

A.C. Hodson
C.M. Christensen


Insects that were particularly active in 1941 included the Pine variety of Cacoecia fumiferana and the Pine sawfly (Diprion simile) on conifers, and the Birch savay (Arge pectoralis), the Birch leaf skeletonizer (Bucculatrix canadensisella), the fall webworm (Hyphantria cunea) and the cankerworms (Alsophila pometaria and Paleacrita vernata) on deciduous trees. The eastern Larch beetle (Dendroctonus simplex) was found to be killing healthy, slow-growing Larch in some localities. A severe epidemic of Spruce leaf rust (Chrysomyxa cassandrae) occurred on Black and Colorado Blue Spruce throughout the northern region of Minnesota, and a heavy infection of Aspen leaf blight (Fusicladium tremulae) was observed in several areas.