A preliminary survey of the Anopheles spp. mosquitoes (Diptera: Culicidae) in South Texas

Endemic malaria transmission has been eradicated from the United States. However, South Texas still remains at risk due to a shared border with Mexico. Decreased efficacy of mosquito control programs in Mexico and similar habitats between northern Mexico and South Texas indicate an increased risk of importation of malaria into South Texas. To understand the potential risk of endemic malaria transmission in South Texas it is important to learn the variation in geographic and temporal distribution of the potential malaria disease vectors. There are 13 Anopheles species currently found in Texas. Anopheles quadrimaculatus is the most competent malaria vector found in South Texas, but other Anopheles species transmit the disease as well. We conducted a four month survey of the mosquitoes in the Lower Rio Grande Valley, the region of South Texas directly bordering Mexico. Collections were made from June through September, when there is high mosquito activity in the Lower Rio Grande Valley. Trapping sites included six locations along the border between Mexico and the United States of America, from Falcon, Texas to Brownsville, Texas. ABC light traps baited with carbon dioxide and resting boxes were used at each site to collect mosquitoes. Specimens collected were identified to species. ARC geographic information system technology was used to analyze current distribution and habitat preferences. We discuss using these data to predict future patterns of distribution of Anopheles spp. mosquitoes and the potential for endemic malaria transmission in South Texas.