Describes the laboratory observations on the effect of light alternated with darkness, temperature, and humidity on the damage caused by the larvae of Dermestid beetle, <i>Anthrenus flavipes Lec. (Vorax Waterh)</i> on woolen fabric. Experimental test data of the percentage loss in weight of the woolen fabric is given to estimate the extent of damage caused by the larvae under different conditions of light, darkness, temperature, and humidity.