Influence of the existence of competitive food on the efficacy of a cockroach bait against the German cockroach, Blattella germanica

Abstract

The influence of competitive food, Hamster Food (Nihon-haigo Oriental Animal Food®), on the efficacy of a cockroach tablet, Maxforce®, was examined using experimental populations of the German cockroach, Blattella germanica (L.). When the distance from the harborage shelter for cockroaches to a bait tablet (5g) was 17cm, two, four or eight pieces of competitive food totally weighing the same as the bait tablet, did not reduce the efficacy of the bait against male adults. The competitive food, however, increased the time to kill female adults, depending on the number of pieces scattered around the harborage shelter. When only one piece of competitive food was placed just beside the bait or the shelter, or halfway between the bait and the shelter, the position of the food did not affect the efficacy of the bait of 17cm distance from the shelter. When a barrier plate with a hole of 1.0×0.5cm square as a passage opening was set between the cockroach bait and the harvorage shelter, even a single piece of competitive food placed on the shelter side greatly reduced the efficacy of the bait against both male and female adults.