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To estimate human exposure to potential vectors of eastern equine encephalomyelitis (EEE) virus, we compared collections of putative EEE virus vectors from human biting collections with collections from CDC, AB (American Biophysics), and New Jersey light traps and resting boxes in enzootic/epidemic foci of EEE virus in southeastern Massachusetts. Human biting collections caught significantly more host-seeking females than resting boxes or unbaited light traps (P < 0.05). Regression analysis of human biting collections to AB traps supplemented with CO2 could predict 60-70% of the actual human biting risk by Aedes and Coquillettidia perturbans. The AB traps supplemented with CO2 and octenol could predict 65% of Anopheles biting risk. No single sampling method was accurate for predicting human biting risk by Culex salinarius, and no method could predict human biting risk by all potential vectors surveyed.

To determine which of 11 trapping methods best sampled populations of 6 potential epidemic vectors of eastern equine encephalomyelitis (EEE) virus, we compared New Jersey (NJ) light trap, CDC light trap, CDC with octenol, CDC with CO2, CDC with CO2 plus octenol, American Biophysics light trap with flickering light (AB flicker), AB steady light, AB flicker with octenol, AB flicker with CO2, AB flicker with CO2 plus octenol, and 3 resting boxes. There was no significant difference between CDC and AB light traps (P > 0.05). The addition of octenol increased trap catch with both CDC and AB light traps; however, this increase was not statistically significant (P > 0.05). Both brands supplemented with CO2 collected more Aedes canadensis, Coquillettidia perturbans, Culex salinarius, and Anopheles spp. than did unbaited light traps (P < 0.05). The addition of octenol to CO2 increased collections of Anopheles spp. and decreased collections of Aedes spp. and Cq. perturbans at some sites, but these changes were not statistically significant (P > 0.05). Resting boxes were best for sampling bloodfed or parous Anopheles spp. The NJ, AB flicker, and AB steady light traps were not effective for sampling potential vectors of EEE virus.

We tested susceptibility to per os infection and potential salivary transmission for eastern equine encephalomyelitis (EEE) virus in Aedes canadensis (Theobald), Aedes vexans (Meigen), Anopheles quadrimaculatus (Say), Anopheles punctipennis (Say), Coquillettidia perturbans (Walker), and Culex salinarius (Coquillett). Culiseta melanura (Coquillett), the documented enzootic vector of EEE virus, was our control. Based on these estimates of laboratory vector competence and other behavioral and ecological components of vectorial capacity, we ranked these 6 species from the most to least probable epidemic vectors: Cx. salinarius, An. quadrimaculatus, Ae. canadensis, Cq. perturbans, Ae. vexans, and An. punctipennis.