Use of German cockroach (Dictyoptera: Blattellidae) fecal extract to enhance toxic bait performance in the presence of alternative food sources

The ability of German cockroach, Blattella germanica (L.), 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. In arenas containing fecal extract and hydramethylnon bait (0.3% [AI]), cockroach mortality was 60% after 5 d. This was significantly greater than the 30% mortality obtained in arenas with hydramethylnon bait but no fecal extract. Chlorpyrifos bait (0.5% [AI]) paired with fecal extract also resulted in significantly higher cockroach mortality (60%) after 7 d than chlorpyrifos bait alone (30%). The LT50 value for arenas with the chlorpyrifos bait/extract combination was 5.7 d compared with 23.5 d for chlorpyrifos bait with no extract. These results indicate that the use of fecal extract in combination with toxic bait may increase the attractiveness of bait stations, decrease bait repellency, and enhance cockroach mortality in the presence of competing food sources.