The effect of water levels on Culicoides furens (Poey) emergence in non-tidal mangrove was studied by daily emergence trapping and water level measurements in various mangrove habitats. A multiple emergence trap forming a complete transect across a canal though mangrove was used to show the relationship of emergence zones to moving and stationary water levels. This and conventional emergence trapping indicated that (a) slowly rising water levels stimulate pupation and emergence and could lead to increases in adult abundance; (b) rapidly rising water levels stimulate pupation and emergence but no increase in adult abundance is likely due to great pupal mortality; (c) most flooded larvae do not seek new water lines but continue their larval life for several months until water levels fall to reexpose mud; (d) some emergence can take place in flooded conditions particularly where pneumatophores are present to give a solid substrate and (e) exposure of swamp mud by falling water levels leads to bursts of emergence especially in the second week after exposure.
