Phenological Partitioning among Drifting Insect Genera within Families in a Subtropical, Coastal Plain Stream (Louisiana, USA)

We investigated invertebrate drift in a subtropical, coastal plain stream in Louisiana, USA. Once monthly, at a single site on Big Brushy Creek, eight three-hour drift samples (24 hours total) were collected using two 250-micron, 0.13-m 2 drift nets. We examined the data for seasonal trends in overall drift density by analysis of covariance and taxonomic composition by principal component analysis and multivariate analysis of covariance. We found no statistically significant seasonal differences in overall drift density, although community composition did statistically differ among months. More interestingly, we found that 26 genera (38%) exhibited asynchrony in peak drift timing within families. Although our study was limited in spatial scope, we suggest that these unusual results emphasize the need for additional invertebrate research in this region.