Habitat characteristics of potential arbovirus vectors: field observations in St. Tammany Parish, Louisiana.

CAMPANELLA R.; WESSON D.M.; CAILLOUET K.; GLEISER, R. M.

Fort Lauderdale, FL. EEUU

Congreso; Entomological Society of America ESA Annual Meeting and Exhibition; 2002

Louisiana forms part of the westward expansion zone for the arboviruses most commonly associated with human disease in the United States. Species such as the ornithophagic Culiseta melanura have long been implicated as maintenance vectors of the Eastern Equine Encephalitis (EEE) cycle, but their habitat preferences are better known for northeastern regions than for the subtropical landscape of the Gulf Coast. This study sheds light on the habitat preferences for this and other Louisiana mosquito species through a multiyear field experiment in a geographically representative study area near Mandeville, Louisiana. Resting boxes, rain gauges, and weather-data loggers were laid out at 15 systematically located sites spanning 26 rural acres. Mosquitoes were collected weekly at the resting boxes and through human landing captures. Geographical parameters (land covers, forest parameters, elevation, topography, and other spatial characteristics) were analyzed and correlated to the total mosquitoes by species and gender caught at each trap, through a customized program built in ARC/INFO Geographic Information Systems. To date, results show 15 species with statistically significant (probability=0.95) correlations to at least one geographical variable, and six species significantly correlated to three to six variables. Results for resting box and landing collections were comparable. Data from 2001 indicate that Culiseta melanura prefers mature, dense forests (pine in this case) with little understory, particularly those near bottomlands and slack water bodies, and are less likely to be found in scrub vegetation or grassy areas. Analyses are being repeated for 2002 and will be compared to 2001 results.