Draft IDENTIFYING MOSAIC DARNERS

Preamble: During the next few weeks I will be uploading some images of Mosaic Darners (Odonata: Anisoptera: Aeshnidae: Aeschna). These will be rather bland images of posed dragonflies taken specifically to show the features useful for identification; they would not win any prizes in a photographic competition. Dunkle's book (1) for all its excellence has some limitations when it comes to identifying some of these species. Note that Dunkle posed many of his specimens, I follow the same technique but chose a 'non-busy' background. These images will be incorporated into an article - a sort of photo key - that I hope will enable readers to identify their Mosaic Darner photos.

If anyone has any decent photos of Mosaic Darners this may be a good time to submit them to BugGuide for potential incorporation in the key.
---------------------------------------------------------------------------------------------------------------------------------
INTRODUCTION
In the field and in photos, the Mosaic Darners consisting of 20 spp. http://bugguide.net/node/view/6322/tree and can be difficult to identify to species. A combination of abdominal pattern and thoracic pattern, with face pattern, eye colour and male abdominal appendages, are generally the most useful characters for species identification. The thoracic pattern is less variable than the abdominal pattern in the Mosaic Darners. The thorax is usually dark with 2 lateral stripes (LS's), an anterior (ALS) and a posterior (PLS). Some species have spots in front of the ALS and in the space between the ALS and PLS. For all Mosaic Darners it is a good idea to get both dorsal views and lateral views of the entire body and particularly a sharp image of the lateral thorax; a head-on photo of the face is also desirable . Another species, Springtime Darner (Basiaeschna janata) is easily confused with the Mosaic Darners and will be included in the 'key'.