Evaluation of food dye marking in the study of sandfly behaviour in Baringo District, Kenya

Abstract

Evaluation of the use of food-dye marking method for the study of sandfly behaviour was carried out in Baringo district, Kenya. A solution of sucrose and food dye was sprayed as bait on the vegetation around a selected source of flies in an animal burrow. The extent of marking and distribution of coloured flies within a radius of 200 m was monitored for four nights. The species caught were Sergentomyia clydei, S. schwetzi, S. antennatus, S. squamipleuris, S. bedfordi, S. africanus S. ingrami and S. affinis and the number of coloured flies was 1017. Feeding on the dyed solution labelled 68.9% of the exiting flies near the burrow and 49.2% of the flies caught at the burrow's entrance. The total number of coloured flies caught at a distance of 50, 100, 150 and 200 m was similar toa linear distribution. The greater numbers of S. clydei caught at 200 m and the smaller numbers of S. squamipleuris and S. ingrami trapped between 50 and 200 m deviated from this pattern. These results are discussed as well as the possible application of the method.