AbstractsGeography &GIS

Distribution patterns of the Anopheles quadrimaculatus (Diptera: Culicidae) species complex in Texas

by Jennifer Ann Murrell

Institution: Texas A&M University
Year: 2007
Keywords: Anopheles quadrimaculatus
Record ID: 1793360
Full text PDF: http://hdl.handle.net/1969.1/4990


The primary vector of malaria in the eastern United States, Anopheles quadrimaculatus (Say), was recently discovered to be a complex of five different cryptic species: A - An. quadrimaculatus, B - An. smaragdinus, C1 - An. diluvialis, C2 - An. Inundatus, D - An. maverlius (Reinert et al. 1997). In this research project, the goals were to determine which species were found in Texas, establish overall distribution patterns of those species, and observe the dates in which each specimens were collected so that any seasonal changes in species could be observed. Both An. quadrimaculatus (A) and An. smaragdinus (B) were identified from collections made throughout Texas from September 2002 through January 2005. Anopheles smaragdinus only made up 3% of the total specimens collected and neither An. inundatus nor An. maverlius were collected in Texas, even though they have both been collected in neighboring Parishes in Louisiana. Anopheles. quadrimaculatus' habitat and geographic range was found to be more extensive than An. smaragdinus. While An. smaragdinus was found only in the easternhalf of Texas with no collection south of Fort Bend County, An. quadrimaculatus was found throughout the eastern half of Texas, many of the southern Golf coast counties, and a few counties in far west Texas. The most common land cover where An. quadrimaculatus specimens were collected was on pasture/hay fields. This is very different from An. smaragdinus specimens in that pasture/hay was one of the least common land covers and the dominant land cover was woody wetlands. Overall, An. smaragdinus was usually associated with land covers that could provide shelter, while An. quadrimaculatus could be found among habitat that was more open and urban. There was no observed change in the species composition over time in this study. In fact, when An. smaragdinus was collected, An. quadrimaculatus was usually collected at the same time. Both An. quadrimaculatus and An. smaragdinus were collected throughout late spring, summer and early fall. Of course, the collection times of these species could have been an artifact of when most of the collectors were looking for An. quadrimaculatus (Say) specimens.