Found at lights on the 1st night of the BugGuide summer gathering in AZ.

I'm not sure whether the light-yellow, almost translucent "tail" (sticking up behind the wing from near the end of the abdomen) is a female's ovipositor, or a male's parameres? I don't know if the male's parameres are ever that exserted, but the "tube" looks much straighter than the ovipositors in other BugGuide post of females...and more pale, striate, and translucent. Then again, perhaps it's just a female holding its ovipositor further back and more straight...it makes sense that the ovipositor would be fairly flexible and maneuverable so that the female can lay eggs in various positions. Compare with the "tail" in the thumbnail below:



Postscript (added 9/1/13): I'm now fairly convinced that the "tail" here is an ovipositor after studying figures depicting the terminalia and genitalia of two species of Trichoscelia, a genus close to Plega in the same subfamily Symphrasinae of Mantispidae (see Fig. 3 and 4 on pg. 211 of Penny [1982](1))