AN OPTIMISED SULFLURAMID BAIT FORMULATION FOR CONTROL OF BOTH PHARAOH'S ANTS MONOMORIUM PHARAONIS (L.) (HYMENOPTERA: FORMICIDAE) AND GERMAN COCKROACHES BLATTELLA GERMANICA (L.) (DICTYOPTERA: BLATTELLIDAE

Abstract:
Containerised insecticide bait products offer considerable advantages for control of urban crawling insect pests. However the differences in insecticide susceptibility and food preference between some pest species have resulted in a diversity of commercial bait products, each targeted at specific insects. However the broad and generally similar food preferences of the two major urban pest insects; the German cockroach Blattella germanica, and the Pharaoh's ant Monomorium pharaonis, has prompted the development of a sulfluramid (AlstarR) broader spectrum bait targeted at both these pests. Laboratory tests were carried out with sulfluramid 0.5% and 1.0% bait in comparison with commercially available hydramethylnon 0.9% bait, against entire Pharaoh's ant colonies. Results indicated that worker ants consumed sulfluramid baits very readily, and mortality appeared between I and 7d after introduction of the bait, depending on the availability of alternative food. Intoxication of the worker ants was rapidly followed by the death of the brood within the nests. Complete kill of the nests was achieved by 28 to 35 days after baiting. Large scale field tests against Pharaoh's ants in apartment blocks and other buildings in Czech Republic showed that sulfluramid baits resulted in a rapid initial reduction in ant numbers, with final elimination of the ants being achieved within 7 to 240 days of baiting, depending on the availability of alternative food sources. Hydramethylnon baits showed a broadly similar efficacy. Against German cockroaches, laboratory tests with sulfluramid 1.0% baits showed the onset of knockdown after Id exposure to the bait, with compete mortality being obtained within 3d. In the same test, hydramethylnon 2.04% achieved complete mortality 7d after exposure to the bait. Field trials in infested apartment blocks showed that both sulfluramid 1.0% and hydramethylnon 1.6% baits achieved and maintained greater than 80% reduction in cockroach numbers over 120d after baiting. During this trial, numbers of cockroaches in untreated apartments showed a 44% seasonal increase in numbers. These data indicate that a single optimised sulfluramid bait product may be used successfully to control both Pharaoh's ant and German cockroach infestations.