Habitat preference of host-seeking Coquillettidia perturbans (Walker) in relation to birds and eastern equine encephalomyelitis virus in New Jersey.

Coquillettidia perturbans (Walker) has been implicated as a bridge vector of eastern equine encephalomyelitis virus in North America. Eastern equine encephalomyelitis virus epizootics occur regularly in wild birds in New Jersey with little or no involvement of susceptible dead end hosts even though high populations of Cq. perturbans are present. Several factors may limit eastern equine encephalomyelitis (EEE) virus transfer from birds to mosquito bridge vectors like Cq. perturbans (Walker), including bird/mosquito density, differences in bird/mosquito habitat preference, mosquito host preference, mosquito host-seeking behavior and mosquito avoidance behavior by birds. Our investigations focused on the host-seeking activities of Cq. perturbans at Colliers Mills Wildlife Management Area in Ocean County, New Jersey. We first examined the abundance of host-seeking Cq. perturbans at a height of 1.0 m in each of three habitats: forest, open field and marsh. We collected significantly more mosquitoes in the forest as compared to the marsh. Forest and field collections did not differ significantly from one another nor did field and marsh. Second, we examined the temporal and vertical distribution of host-seeking Cq. perturbans in a sylvan habitat at three heights (1.0, 2.5, and 6.0 m) from dusk to dawn. We found that Cq. perturbans did significantly more host-seeking during the night period than either the evening or morning. Host-seeking mosquitoes also tended to stay near the ground and at no time did they ascend into the forest canopy. Host-seeking Cq. perturbans and their apparent spatial disparity to roosting/nesting birds are discussed as a possible barrier to the transmission of EEE virus in New Jersey.