Life history and trophic basis of production of the mayfly Callibaetis fluctuans (Walsh) (Ephemeroptera : Baetidae) in a mitigated wetland, West Virginia, USA

We determined the life history, secondary production, and trophic basis of production for Callibaetis fluctuans in a mitigated wetland at the Green Bo ttom Wildlife Management Area, Cabell County, West Virginia, USA. Quantitat ive benthic samples were collected from three sites covering a range of wat er depths and vegetation types from January to December 1994. Length-freque ncy histograms were constructed for each sample date, and secondary product ion was calculated using the size-frequency method. Foregut analyses were c onducted seasonally to determine diet. Callibaetis fluctuans had a multivol tine life cycle with at least three cohorts. Fast larval growth occurred du ring the spring and fall, whereas an overwintering cohort had slower growth . Total annual production was 208.0 mg.m(-2).yr(-1) (AFDM) with a productio n-to-biomass ratio of 12.6. Amorphous detritus comprised >80% of the diet i n all seasons and accounted for 70% of total production. To account for thi s production, C. fluctuans consumed 3675 mg.m(-2).yr(-1) of detritus. This is one of the first studies to provide production estimates for an aquatic insect in a permanently inundated wetland.