Update November 06, 2014: Added an immature male at the bottom of the page:
Update September 03, 2010: Added a mature female at the bottom of the page:
Update September 18, 2008 : Added a mature male at the bottom of the page:
Update: Dr. John Abbott and Dennis Paulson have independently confirmed the identity as T. septima.
Initially I had thought that this female darner found resting in deep cover next to Willow Pond #1 at Santa Ana NWR on June 22, 2005 was a Blue-faced Darner Coryphaeschna adnexa, but now I believe it is a Pale Green Darner Triacanthagyna septima.
Examine the exact pattern of the thoracic sutures, and compare them to images of female T. septimahere and here, and then to female C. adnexahere and here. :
Note the leg color; in Coryphaeschna adnexa the legs are black, while those of Triacanthagyna septima are pale:
Now look at the wing veination: referring to the genus wing illustrations in Needham, Westfall and May:-
- the 5 cells in the triangle (arrows "A" below) are correct for Triacanthagyna and wrong for Coryphaeschna which has 4 cells (having only one cell along the inner edge of the triangle compared to two in Triacanthagyna).
- In the band of cells above the triangle (arrows "B" below) the point of the triangle meets the vein between the first and second cells of this band; correct for Triacanthagyna, but Coryphaeschna has this point of the triangle fall inside the first cell.
In the area at the lower base of the forewing (arrow "C" below) there is only one "unsplit cell" before a series of split cells extending out to the lower point of the triangle; this is correct for Triacanthagyna, while Coryphaeschna has two narrower "unsplit cells".
- Note the complete lack of any amber tinting in the wing bases (C. adnexa females mostly have some amber tinges at the wing bases).
If my ID is correct, this would become the first photo record for Texas (and the second record for the U.S.), so I'd appreciate feedback - thanks.
Update September 18, 2008 : A mature male from Santa Ana NWR on September 17, 2008:
Update September 03, 2010: This female was in Terry Fuller's yard, Cameron county on September 03, 2010:
Update November 06, 2014: this immature male was in the woods at Sabal Palm Audubon Sanctuary, Brownsville, Cameron county, Texas on October 30, 2014: