Species Composition, Abundance and Population Structure of Indoor Resting Mosquitoes in Two Villages of Sudan

Author(s): Mashair Sir El Khatim Mustafa, Zairi Jaal, Sumaia M A Abukashawa, Siti Azizah Mohd Nor

Background: Frequent monitoring of mosquito vector populations is a strategy of great importance for reducing risks of disease occurrence. In Sudan, malaria is still a major threat to public health. Insecticide-based control has been undertaken for years, but there is no noticeable decrease in malaria infection nationwide.

To overcome this situation, a better understanding of the mosquito vector breeding site ecology is relevant. Here, we investigate the species composition of malaria vectors, breeding sites, seasonal abundance, and population structure in two different villages.

Methodology: Monthly sampling of adults and larvae were performed in Abu Algoni (Sennar State) and Algerif West (Khartoum State) based on the prevalence of the vector and malaria parasite from June 2010 to May 2011. In total, 4,932 mosquitoes comprising of 3047 larvae and 1885 adults (males and females combined) were sampled. During each visit, immature stages were collected from potential breeding sites using dipping technique. In addition, adults were collected indoors from houses by aspiration and indoor pyrethrum spray methods. Mosquitoes were identified morphologically, the Anopheles gambiae complex identified to species level using well accepted morphological keys and PCR amplification. The physiological status of all An. arabiensis females were initially inspected by eye and then confirmed under the microscope after dissection of the abdomen. The proportion of fed, unfed, half-gravid and gravid were counted. Unfed and freshly fed females collected by indoor resting spray catch with developing ovaries not beyond Christopher’s stage II were dissected and examined monthly for parity rate and estimation of mosquito longevity.

Environmental parameters namely temperature, rainfall and humidity were obtained from