The breeding sites of Culicoides pachymerus
are described for the first time in western Boyacá Province, Colombia, where this species is a public health problem. In addition to being a nuisance due to its enormous density and its high biting rates, C. pachymerus
cause dermatological problems in the human population. Analysis of microhabitats by the sugar flotation technique and the use of emergence traps allowed us to recover 155 larvae of Culicoides spp
and 65 adults of C. pachymerus
from peridomiciliary muddy substrates formed by springs of water and constant rainwater accumulation. These important findings could aid in the design of integrated control measures against this pest.