Studies in Mothproofing: Part III: Patterns of Damage Caused in Moothproofed Woolen Fabrics by Two Species of Clothes Moth

Abstract

The efficacy of dieldrin (1–0.0009% on fabrics), Mitin (16–0.156%), and Eulan U33 (6–0.0058%) was tested with 30-day-old larvae of Tinea pellionella (L.) and 25-day-old larvae of Tineola bisselliella (Hum.) at 25° C and 75% RH, raised on dried fish and yeast. With higher concentrations of the proofing agents, all larvae died within one or two weeks, and the damage was 0.05–4 mg per 10 larvae, depending on the concentration. With less proofing agent, the damage in the first week (20–35 mg) was increased in the next three weeks to a total of 130–200% of the first amount, the mortality was low, and pupation began from the third week. At concentrations between these, the damage was 7–10 mg and the mortality was 100%. All three mothproofing agents were somewhat more effective against Tineola than Tinea. As compared with the Attagenus larvae, these clothes moths are slightly less susceptible to dieldrin, more susceptible to Eulan U33, and show about the same susceptibility to Mitin.