powder

powder] The American cockroach, Periplaneta americana is the largest of house-infesting cockroaches and causes ’ public health problems making it an strategic target for control.Different concentrations of Boric acid and neem tree leaflets (old of young developmental stage, OY) powders were used in this study. The powders were incorporated into food mixtures designed here to produce baits and the lethal dose (LD50) was calculated for each treatment.For both treatments, the toxicity was found to relate with the amount ingested by a cockroach (mg / cockroach). Increased concentrations of Boric acid were found toxic to P. americana and mortality percentage increased in a positive correlation with concentration. LD50 was 2.0889±0.00136 g. On the other hand, two effects were observed for neem OY leaflets: a) a toxic effect and increase in mortality for concentrations up to 3.75g with LD50 =4.345±0.07694 g; and b) a repellent effect as well as a decrease of mortality for baits with concentrations of 5g-6.667g