Evaluation of Diflubenzuron as a Control Agent for Hemlock Looper (Lepidoptera/ Geometridae)

1988

3 Abb., 5 Tab., 34 Lit. Ang.

Unselbständiges Werk

10622

200042620

Diflubenzuron, a benzoylphenyl urea that selectively inhibits chitin synthesis in insect larvae upon ingestion, was aerially applied on a infestation of hemlock looper, Lambdina fiscellaria fiscellaria (Guenee), in a stand of balsam fir, Abies balsamea (L.), near Bay D'Espoir, Newfoundland. A single application of 70 g (AI) in 4.7 liters/ha, applied when 75% of the larvae were in the second instar, resulted in 92% reduction in pupal population but when the same amount was applied twice, 2 wk apart, both larval and pupal populations were reduced by 99%. A double application of diflubenzuron at the rate of 70 g (AI)/4.7 liters per hectare is recommended for the effective control of the hemlock looper. Merits of spraying at an earlier stage of insect development to obtain better foliage protection, and the use of lower volume rate to increase the payload of the aircraft, are discussed.