In this phase II application, we propose to test the efficacy of our platform technology derived product, ContraPest(R), a chemosterilant rat bait containing 4-vinylcyclohexene diepoxide (VCD), in reduction of the brown rat population in a model urban setting, the subway stations of New York City (NYC). Our phase II application is comprised of 3 aims. Aim 1 is focused on establishing the safety parameters of our technology, including exclusion of non-target species and impact on the environment. Aim 2 is focused on establishing the feasibility of performing pilot studies in NYC using wild caught brown rat populations both from Arizona and from NYC. Aim 3 is focused on performing a series of pilot studies in NYC to test the efficacy of ContraPest(R) bait in reducing the brown rat population in defined areas of the subway stations in NYC. In phase I we successfully demonstrated the efficacy of orally administered VCD in reducing primordial follicle number and litter size in R. norvegicus laboratory rats (the same species as the brown rat of NYC). We also determined that our current agricultural bait formulation (a pellet bait) is highly palatable to laboratory ras and consumption of our bait results in reduction in fertility in females. Current rat control practices in NYC are focused on rodenticide use. Poison packs are thrown off the back of subway trains onto the tracks. This is largely ineffective primarily due to the abundance of more palatable food choices (i.e. trash) and because poison application frequently results in population rebound effects. While there is no magic bullet to reducing rat pest populations, we believe that our technology can be used as an adjunct to current rodent pest management practices to have a sustainable significant impact on the reduction of the urban brown rat population. PHS 398/2590 (Rev. 06/09) Page Continuation Format Page