60 Records

Status

Georgia River Cruiser (Macromia illinoiensis georgina) is the southern form of the Swift River Cruiser, formerly split as a separate species. This taxon occurs on rivers and creeks on the Eastern Shore, and on the southern coastal plain and piedmont. The two readily intergrade where ranges come into contact in the piedmont, and individuals there may show characteristic of either form (Richard Orr's Dragonflies and Damselflies of Maryland and the District of Columbia). This subspecies is ranked as S3 (watch list) in Maryland.

Description

Georgia shows half-length yellow antehumeral stripes on thorax (absent on Illinois), and a complete yellow ring on S2 (broadly interrupted dorsally and laterally on Illinois). Yellow markings generally more developed and larger than on Illinois. Male Illinois shows yellow dorsal spots on middle abdominal segments very reduced or absent. Male Illinois shows black auricles (Dunkle, 2000).