The jack pine tip beetle (Conophthorus banksianae McPherson) attacks the shoot tips of jack pine (Pinus banksiana Lamb.) and other pines, killing the apical one inch of the shoot and thus causing crooks and forks in the branches and main stem. Several recent studies on the insect have present the bionomics, host relations, and mortality (McPherson, Wilson, and Stehr, 1970; McPherson, Stehr, and Wilson, 1970; Hall and Wilson, 1974), as part of a project to learn its importance to the forest resource and to seek potential control methods. In the part of the study reported here we wanted to know the vertical distribution of attacked tips on the host in order to more readily understand the insects' injury to a stand of pine. Casual observation indicated that the attacked tips appeared to be aggregated in the tops of the crowns and were especially abundant on taller trees. Therefore we examined vertical distribution of attacks in relation to tree height, degree of exposure of the attack site to the sky (celestial hemisphere), and shoot tip size.
Hall, David J. and Wilson, Louis F.
"Within-Tree Distribution of the Jack Pine Tip Beetle, Conophthorus Banksianae McPherson, on Jack Pine,"
The Great Lakes Entomologist: Vol. 7
, Article 4.
Available at: http://scholar.valpo.edu/tgle/vol7/iss3/4