Clonal variation in susceptibility to coneworms (Dioryctria spp.) in young loblolly pine seed orchards

Twenty-five loblolly pine seed orchards were examined for coneworm damage over a 3 year period. Eight of the twenty-five orchards were found to have significant clonal variation in coneworm infestation rates. Susceptibility among those eight orchards ranged from 0 to 67 percent infested cones. Infestation rates were not correlated with performance values for height or diameter. Selection against susceptible clones of "custom-designed" insecticide treatments may successfully reduce this pest problem and minimize the need for large scale orchard-wide chemical control measures.