Temporal Variation in Species Abundance and Richness of Culicoides (Diptera: Ceratopogonidae) in a Tropical Equatorial Area.

ABSTRACT

The aim of this study was to investigate whether temperature, rainfall, and humidity influence the annual distribution of Culicoides Latreille 1809, species abundance and richness in rural areas on São Luís Island in the state of Maranhão, Brazil. Biting midges were collected in housing for domestic animals in the peridomestic areas of 10 homes. A CDC light trap was installed in each peridomestic area from 600 p.m. to 600 a.m. once a month for 12 mo. In total, 23,633 individuals belonging to 26 Culicoides species were captured. The most abundant species were Culicoides diabolicus Hoffman, 1925 (27.43%), C. ignacioi Forattini, 1957 (25.9%), C. flavivenulus Costa Lima, 1937 (15.53%), C. insignis Lutz, 1913 (10.66%), C. filariferus Hoffman, 1939 (6.21%), C. boliviensis Spinelli & Wirth, 1984 (6.07%), C. foxi Ortíz, 1950 (2.83%), and C. leopoldoi Ortíz, 1951 (2.54%). Species richness and abundance were greater during the rainy season (24 species; 88% of the individuals) than during the dry season (18 species; 12% of individuals). However, persistent rain on the days the midges were collected or in the preceding 24 h adversely affected abundance. Mean monthly maximum temperature and rainfall on the day of the collection adversely affected Culicoides abundance and richness.