Broadcast application of a placebo rodenticide bait in a native Hawaiian forest

This study consisted of three replicates of controlled field trials using a pelletized placebo (Ramik(R) Green formulated without diphacinone) bait tr eated with a biological marker and broadcast at three application rates - 1 1.25, 22.5 and 33.75 kg/ha. We determined that Polynesian (Rattus exulans) and roof rats (Rattus rattus) consumed this bait when broadcast on the grou nd and assessed the optimal sewage rate to result in maximum exposure of ba it to the rats while minimizing bait usage. All Polynesian rats captured in all application rates had eaten the bait. The percentage of roof rats that had eaten the bait increased with application rate, however, 22.5 kg/ha wa s clearly the optimal application rate. Bait degradation and invertebrate a ctivity was documented and assessed. Published by Elsevier Science Ltd.