Lincoln National Forest, Guadalupe Ranger District, Eddy County, New Mexico, USA
August 5, 2015
Size: 30 mm
Download high resolution image here.
This beetle came to a
mercury vapor lamp set-up on 05 August 2015 in Turkey Canyon at 5400 ft. elevation on Forest Road 527,
Lincoln National Forest, Guadalupe Ranger District within
Queen 7.5 minute quadrangle, Eddy Co., NM. Several other
insect images from this event are posted.
The dorsal view alone indicates this beetle is either
Enaphalodes atomarius or
cortiphagus. Lingafelter and Chemsak's key
(1) states, "Pubescence of metasternum primarily translucent" for the former and, "primarily white and not translucent" for the latter. The degree of translucence cannot determined from either the
full ventral view or even the
central metasterum closeup, since both images are taken with a highly diffused flash. One can see from the latter, though, that there are two distinct types of setae. The majority type are thicker, longer, and darker than the minority type. In the image of the
metasterum with highly oblique illumination coming only from the left, one can see blurry irregular patterns of light coming from the majority type. These patterns shift as the perspective angle is changed when viewed under a stereo microscope with similar illumination. This indicates that it is refracted and diffused light passing
through the setae. That is, it is translucent and, therefore,
E. atomarius.