Light trap collections of ovipositing Simulium squamosum in Ghana.

At a site near Boti waterfalls in southern Ghana a total of 14 644 female and two male Simulium squamosum were caught in four nights in Monks Wood light traps. The highest catch, of 6520 females, was obtained in a single night with an ultraviolet light tube that had a one-second flash rate. About 12% of the females caught were gravid and dissections of non-gravids showed that they had oviposited very recently. The traps were clearly catching females before or soon after oviposition. The same traps caught none or very few blackflies when placed in two other localities near Akosombo. Trap location appeared very important in sampling ovipositing females of S. squamosum.