Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/1996
Publication Date: N/A
Citation: Interpretive Summary: Numerous food and chemical materials have been tested in cockroach bait formulations in an attempt to improve bait attractiveness. However, the effectiveness of even the most attractive toxic bait formulations is severely reduced in the presence of competing food sources. Aggregation pheromone is a natural attractant known to influence German cockroach behavior. The pheromone is produced in the rectal pads of the cockroach and passed with the feces. An extract of German cockroach fecal material has never been evaluated as an attractant in toxic bait formulations. The purpose of this study was to determine if placing fecal extract next to a toxic bait would enhance German cockroach mortality when they were provided with several competing nontoxic food sources. Two toxic bait formulations were tested. Mortality in test arenas where fecal extract was placed next to the hydramethylnon bait was double that of arenas with no extract. Cockroach mortality was also doubled in tests where fecal extract was paired with a more repellant, chlorpyrifos bait formulation. The placement of fecal extract next to the toxic bait formulations significantly improved cockroach kill even in the presence of five nontoxic alternative food sources. German cockroach fecal extract has potential to be used for improved baiting technology. The use of fecal extract in combination with toxic bait can increase the attractiveness of bait stations, decrease bait repellency and enhance cockroach kill in the presence of competing food sources.
Technical Abstract: The ability of German cockroach (Blattella germanica) fecal extract to enhance toxic bait performance was evaluated in tests where a toxic bait was housed adjacent to the extract in arenas containing 5 alternative food sources. Mortality (60%) in arenas containing fecal extract and hydramethylnon bait (0.3% AI) was significantly greater than that in those with no fecal extract present (30%). Chlorpyrifos bait (0.5% AI) paired with fecal extract also resulted in significantly higher cockroach mortality (60%) than chlorpyrifos bait alone (30%). The LT50 value for arenas with the chlorpyrifos bait/extract combination was 5.71 d compared with 23.55 d for chlorpyrifos bait with no extract. These results indicate that the use of fecal extract in combination with toxic bait can increase the attractiveness of bait stations, decrease bait repellency and enhance cockroach kill in the presence of competing food sources.