Vertical distribution of flying black-flies (Diptera: Simuliidae) in Central Nigeria

Flying black-flies were collected using an array of 4 nets mounted on a vehicle at heights between 0.15 and 3.0 m above the ground. The vertical distribution differed amongst the 8 most abundant species, but within a particular species such as S. squamosum, there was no significant difference in the vertical distribution of the males and females, nor between females of different physiological conditions. This infers that the height of the trap on the vehicle will not normally be a source of bias during population studies. However, there was some evidence of circadian changes in the vertical distribution; during the afternoon, black-flies of all species flew higher compared with in the evening.