The attraction range of the Onderstepoort 220V light trap for Culicoides biting midges as determined under South African field conditions.

Despite some limitations suction light traps are the primary tools used for the collection of Culicoides species (Diptera: Ceratopogonidae). The range of attraction of the Onderstepoort light trap is not known but an insight into the range of a trap will determine where the trap must be positioned relative to the hosts present, possible breeding sites and environmental structures in the trapping vicinity. It will therefore contribute to a more meaningful interpretation and comparison of results between trapping events. In the present study the number of Culicoides midges collected in a single trap was compared to those of traps made with an additional trap respectively 1m, 4m and 8.5m away from the first. Treatments between sites were rotated in three replicates of a 4×4 Latin square design. While interactions were found in traps 4m apart no statistically significant interactions were found when they were 8.5m apart. The range of attraction, indicated by the interaction between two traps, will be between 2m and 4m. In interpreting light trap results the limitations of this collection method needs to be taken into consideration.