Collection of Culicoides spp. with four light trap models during different seasons in the Balearic Islands

Bluetongue (BT) is a viral disease that affects ruminants, being especially pathogenic in certain breeds of sheep. Its viral agent (bluetongue virus; BTV) is transmitted by several species of Culicoides biting midges (Diptera: Ceratopogonidae). Different models of suction light traps are being used in a number of countries for the collection of BTV vector species. To determine the relative effectiveness of different light traps under field conditions, four traps (Onderstepoort, Mini-CDC, Rieb and Pirbright) were compared. These traps were rotated between four sites on a cattle farm in Mallorca (Balearic Islands, Spain) for several non-consecutive nights. Results showed remarkable disparities in the efficacy of the traps for the collection of Culicoides midges. The highest number of midges collected in the Onderstepoort trap (x¯ ± SD = 62 ± 94.2) was not significantly different from that collected in the Mini-CDC (x¯ ± SD = 58 ± 139.2). The Rieb trap collected the lowest number of midges (x¯ ± SD = 3 ± 4.0). Significantly higher mean numbers of midges were collected in the Onderstepoort than in either the Pirbright (P = 0.002) or Rieb traps (P = 0.008). There were also differences in the Culicoides species composition as determine with the various traps. These results indicate that the Onderstepoort or Mini-CDC traps will be more effective than either the Rieb or Pirbright traps for the collection of large numbers of Culicoides midges.