Seasonal distribution and relationship to temperature and precipitation ofthe most abundant species of Culicoides in five provinces of Andalusia, Spain

A total of 177,344 Culicoides specimens were collected from 3,109 light tra p collections made weekly from August 1990 to October 1991 at 62 sites in t he provinces of Cadiz, Cordoba, Huelva, Seville, and Malaga, Spain. Reporte d for the Ist time are Culicoides agathensis, Culicoides bahrainensis, Culi coides marcleti, and Culicoides odiatus in the Iberian Peninsula, and Culic oides scoticus in Andalusia, Spain. As a group, Culicoides were active thro ughout the year. The 3 most common species were Culicoides imicola (56,254) , Culicoides newsteadi (24,359), and Culicoides circumscriptus (16,720). Nu mbers of C. imicola peaked in October, C. newsteadi peaked in May, and C. c ircumscriptus peaked in June. Based on regression analyses, the optimal min imum and maximum air temperatures, respectively, for adult insect activity were approximately greater than or equal to 18 degrees C and greater than o r equal to 38 degrees C for C. imicola, 12 degrees C and 24 degrees C for C , newsteadi, 14 degrees C for C. circumscriptus (minimum temperature only), 16 degrees C and greater than or equal to 38 degrees C for "other" Culicoi des, and 14 degrees C and 32 degrees C for total Culicoides. Optimal minimu m and maximum temperatures could not be determined for Culicoides pulicaris , Culicoides punctatus, subgenus Monoculicoides, and the Culicoides obsolet us group. During August and September, the months when African horse sickne ss outbreaks occurred, C. imicola was the predominant species in the coasta l Mediterranean zone. If the "other" Culicoides spp. group was not consider ed, the predominant species were C. imicola in the Guadalquivir River valle y zone, C. newsteadi in the Subbetica mountainous range zone, and subgenus Monoculicoides in the coastal Atlantic zone.