Allegheny River Cruiser Macromia alleghaniensis Williamson, 1909S2 (State rare)  
Kingdom Animalia   >   Phylum Arthropoda   >   Class Insecta   >   Order Odonata   >   Family Macromiidae   >   Genus Macromia   

Status:

Allegheny River Cruiser (Macromia alleghaniensis) is very similar to the northern form of Swift River Cruiser, Illinois River Cruiser (Macromia illinoiensis illinoiensis), and normally identifiable only in the hand. This species has an extensive range east of the Mississippi, mostly through the Appalachians and portions of the Piedmont (Dunkle, 2000). It generally prefers slow-flowing rivers and creeks (Paulson, 2011). Allegheny River Cruiser is recorded from four counties in western Maryland and the piedmont, along the Potomac and larger tributaries (Richard Orr's Dragonflies and Damselflies of Maryland and the District of Columbia). It is ranked as S2 (state rare).

Description:

In the hand, male has S7 completely encircled by yellow (yellow only dorsally and laterally on Illinois), S2 nearly completely encircled with yellow (widely interrupted dorsally and laterally by black on Illinois), normally with a only small interruption dorsally. Mesotibial keel short (14-20% of tibia), while longer on Swift (25-50%). Slight differences in wing venation. Females are very difficult to separate. This species on average shows proportionately longer legs (Dunkle, 2000). Females showing mature green eyes and untinted wings could possibly point to Alleghany, but more study needed (Paulson, 2011).

There are 6 records in the project database.

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An Allegheny River Cruiser in Allegany Co., Maryland (7/9/2006). Photo by Steve Collins. (MBP list)

An Allegheny River Cruiser in Allegany Co., Maryland (7/9/2006). Photo by Steve Collins. (MBP list)

Closeups of the cerci of an Allegheny River Cruiser in Allegany Co, Maryland (7/9/2006). Photo by Steve Collins. (MBP list)


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