Volcano Mosquito Dissections

Mosquito-borne avian malaria is a key limiting factor on Hawaiian forest bird populations. Preservation of endemic forest birds and restoration of Hawaiian forest bird communities will rely on mosquito control. While landscape level control is being developed managers need short term and reliable tools for monitoring and controlling mosquito populations to protect remaining breeding bird populations. As part of a larger study on the efficacy of the biopesticide VectoMax FG for control of larval Culex quinquefasciatus and adult mosquito traps for monitoring, USGS personnel evaluated host-seeking trap configurations and gravid trap lures for capturing adult mosquitoes (Culex quinquefasciatus and Aedes japonicus) in native forest habitat from August to November 2017. Four trap sites were selected in a forest tract in Volcano Village. Traps were arranged in a 100-meter square and trap types and lures were rotated through each site during each week of the study in a latin square design. Both host-seeking traps (Biogents Sentinel Traps and CDC miniature light traps) and CDC Gravid Traps were operated nightly at each site from 1600 to 0700 hr the following morning. Collected mosquitoes were maintained on a 3% sucrose solution and later dissected for malarial diagnostics. Midguts and salivary glands were examined under compound microscopy (450X) for evidence of infection. Oocyst presence and intensity and sporozoite presence and relative intensity were recorded. The data provides for a comparison of trap types and lures for deriving malaria prevalence data and a useful measure of transmission risk at this time and place.