Variable Darner Aeshna interrupta was the most common Aeshna in Anchorage and Matanuska-Susitna Boroughs, Alaska during late July and early August 2007 - but there were two distinct forms seen:-
A form with complete (but narrowed in the upper center) lateral thoracic stripes was very common, with on one occasion swarms of thousands over some coastal marshes; I presume this form to be lineata:
typical males:
a typical female:
The other form was much less common - I saw perhaps a dozen in total and got photos of three; this form has the lateral thoracic markings reduced to a small but distinct pale elongate spot at the ventral end of the anterior stripe position, plus sometimes a very indistinct short, thin "ghost"line at the upper end of the anterior stripe position and a similar ghost-image at the bottom of where the posterior stripe would have been. In most cases where I could see the pattern well, the two ghost marks were either barely present or actually missing, such that even from fairly close range, it appeared that the only mark on the side of the thorax was the small pale dot above the legs:
I also saw one individual that appeared to by typical of interrupta, with large pale, clearly-separated spots instead of stripes - at least on the anterior stripe; the posterior stripe may have been more like the "unmarked" form above:
