Effects of uv irradiation of nymphs of Blattella germanic and Periplaneta americana

Certain effects of uv irradiation on nymphs of the American cockroach, Periplaneta americana (L.), and the German cockroach, Blattella germanica (L.), were investigated. Of 7 wavelengths to which the nymphs were exposed, 254 and 265 nm were the most effective in producing mortality. The approximate LD50 dose for nymphs exposed to germicidal (254 nm) uv was 4.56 x 104 μ j cm-2 for P. americana and 1.9 x 104 μj cm-2 for B. germanica. UV irradiation resulted in retarded feeding and delay in weight gain and molting. Structural abnormalities were observed among adults of those nymphs which were exposed to either pulsed or continuous uv. Pulsed uv was more effective in producing mortality than continuous uv exposure. Nymphs lured to a specific area by food, water, food and water, contaminated filter paper, or filter paper containing a crude extract of aggregation pheromone were killed when irradiated with germicidal (254 nm) uv