Key to common families of insects in the Niagara region
18a) Gills not present on abdominal segments 1 and 2. Contrasting pattern of black and yellow
usually evident. PERLIDAE

18b) Gills present on first two abdominal segments. Generally dark and blackish in colour,
without any pattern. PTERONARCYIDAE
Return to Couplet 17
Return to BioMAP Central