Control of the Balsam Woolly Adelgid (Homoptera: Adelgidae) in Fraser Fir Christmas Tree Plantations1

Abstract

Single applications of 0.51% insecticidal soap/diazinon (40%:0.4% AI), 0.52% insecticidal soap/methoxychlor (38.7%:3.0% AI), 0.01% fenvalerate, 0.01% permethrin, and one and two applications of 0.63% Safer’s insecticidal soap were tested against the egg, crawler, nymph, and adult of the balsam woolly adelgid, Adelges piceae (Ratzeburg). With the exception of the soap/methoxychlor, all materials appeared to be effective against nonegg stages. The residual toxicity of fenvalerate and permethrin killed all nonegg stages, resulting in no egg production in later samplings. Fenvalerate and insecticidal soap did not adversely affect nontarget organisms in the litter. Fenvalerate showed no phytotoxicity applied to Fraser fir, Abies fraseri (Pursh) Poir. Christmas trees at 0.01, 0.02, 0.04, and 0.08% concentrations. A soap discoloration study indicated that succulent foliage (June growth) may be sensitive to soap treatments, but multiple sprays of either high or low concentrations may be used with little discoloration at times later than June.