Across the Colorado River from Needles, and a few miles south, Mohave County, Arizona, USA
August 3, 2015
This was the first of several of these mydids encountered perched on stems of the shrub Pluchea sericea
, growing on the levee above the Colorado River. This one was by itself, but the second group (found about 45 minutes later) consisted of about 6 individuals...at least one of which was a mating pair...all perched near each other about 6' above the ground.
This keyed to genus Mydas
in the MND(1)
. Going through the online key to Mydini at Torsten Dikow's web site
led to M. ventralis
. That's what I had expected, based on browsing BugGuide and other images on the web and comparing with the MCZ type of M. rufiventris
and the description of M. abdominalis
, both of which are synonyms of M. ventralis
. I'd also like to run this through the 1926 revision of Mydidae by C. W. Johnson, but haven't yet been able to access that reference.
In order to get to M. ventralis
in Torsten's online key, one needs to have "alula black", which can seen to be the case in the 2nd image of the series here. But in at least one of the (otherwise similar looking) individuals seen in this population the alula appears completely hyaline. I presume this is simply variation which doesn't "respect the key" (as often seems to happen in taxonomy, despite a key writer's best efforts).
These seem to me like they may be mimics of the scoliid wasp Triscolia ardens
QUESTION FOR COGNOSCENTI: Is there a simple way to tell whether this is a male or female? (For example, from the available view of the terminalia?)