Bidentate Nomada Male Key
Attached is a dichotomous key to the eastern male forms of bidentate Nomada.
I have been working on this particular group and the associated females for quite a long time. I have seen many of the holotypes, many identified specimens, and several nice collections from several of you (thank you very much!). I have sorted, resorted, scored, rescored, used cluster analysis, read the literature still feel that things are still not settled. However, some patterns have emerged and I believe that I am near the end of what I can do through direct measurement and observation. There is an opportunity to do some molecular work on this group in the future and I hope that will help sort things out a bit further.
The guide below, with the exception of well defined Nomada maculata, uses the term Form and a series of letters to denote different groupings. The reason for this is that there are a number of problems with the names of the holotypes and their associations with names in collections, there are some likely synonyms, and there appears to be some major mismatches between Robertson's types and what has been the common naming practice. This and the problem of my lack of clarity in species boundaries has led me to believe that for the time being it would be better to leave things as a set of numbered forms that can be later associated with names. In the mean time, people doing ecological work have (hopefully) a clearer and more consistent means of splitting their specimens.
Any comments are very welcome as are large collections of this group from one locality that could inspect.
P.S. I will send out a key to the more difficult females next then some general short accounts.
Sam Droege Sam_Droege@...
w 301-497-5840 h 301-390-7759 fax 301-497-5624
USGS Patuxent Wildlife Research Center
BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD 20705
Out beyond ideas of wrongdoing and rightdoing,
there is a field. I'll meet you there.
When the soul lies down in that grass,
the world is too full to talk about.
Ideas,language,even the phrase " each other"
doesn't make any sense