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  "Illinois" Swift River Cruiser
            Macromia illinoiensis illinoiensis Walsh, 1862

Species distribution map

Range & Habitat:

The nominate northern race, it is found in northwestern New Jersey, replaced by the southern race on the coastal plain.  Intergrades occur, especially in Somerset and Hunterdon counties.

Patrols along rivers and large streams.

'Northern' Illinois River Cruiser male dorsal 

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Description:

Mostly blackish, with a single lateral yellow thoracic stripe, small spots on abdominal segments 1-4 and a large dorsal spot on S7.  For comparison, see "Southern" Illinois River Cruiser which is the southern race.  The reduced abdominal spots are representative of the northern race.  On the coastal plain, the Allegheny River Cruiser has a similar pattern to this form, but its range does not overlap in New Jersey.  Caution: intergrades do occur from Hunterdon & Mercer through Monmouth.  Not all can be identified as to type.  More study is needed of this genus.

 

Conservation Status:

State: S4 - Apparently secure in New Jersey

Global: G5T5 -  

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Flight season:

Early Date: 5/27
Late Date: 9/17

Please scroll down for monthly graph.

 

Flight Season

(hover your mouse over the bar for actual data)
 
Number of Records
14 
1 8 12 14 3
J F M A M J J A S O N D

Months

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Click here for acknowledgments
Date, distribution, and status data courtesy of Allen Barlow, NJOS

© 2006 Jim Bangma, NJOS  Comments or suggestions?  Use the Feedback Form