Loading ...
Sorry, an error occurred while loading the content.

1955Looking for Nomada with only 2 submarginal Cells

Expand Messages
  • Sam Droege
    Feb 4 10:51 AM
    • 0 Attachment

      We are interested in any 2 submarginal celled Nomada you may have from the prairies or Eastern North America.

      Sophie Cardinal (now at the Canadian National Collection and revising N. Am. Nomada) and I have been playing around with some new Nomada barcoding data and found a second specimen of a very interesting species.  

      These 2 specimens may represent the 4th species of Nomada in North America with 2 submarginal cells (that we know about).

      The 3 species on the books are:

      N. detrita - One male described by Mitchell - No other specimens found
      N. obliterata - A reasonably regularly found species that is large and colorful and whose western populations my have 3 submarginal cells (working on that one)
      N. victrix - A SW / Mexican species

      ??? - Are there any other species in the West/Mexico/South America with 2 submarginals?

      All 3 look vastly different and thus 2 celledness appears to have independently arisen.

      Here is what we know about the 2 species we have on hand:

      Both are females
      • 2 submarginal cells with the cross vein creating 2 equal sized cells
      • tiny, tiny, the size of N. parva or a bit smaller
      • mandibles long, thin
      • cheek wide
      • antennae relatively hairy with several prominant setae towards the tip (for Nomada)
      • F2 > F1
      • F2 > F3
      • hind tibial setae similar to white setae species such as N. parva, N. cressonii, but possibly a bit thicker
      • rear face of thorax very distinctive , best way to describe it is that the rear face of the propodeum the metanotum and scutellum are all in one plane....thus the scuttellum looks almost flat
      • lateral yellow maculations on t2 are huge; almost completely round with a single black cut out...not following the normal model of Nomada maculations
      • CO1 puts it by itself between Centrias species on one side of the tree and N. supurba species on the other ... no where near the parva group.

      The only described species that these could possibility be is N. detrita
      • The type for N. detrita is unfortunately a male,
      • however, it appears to be not this species
      • I have seen the type and my notes indicate that it is
        • very similar to N. pygmaea in size,
        • does not appear to have a modified thorax/propodeum
        • the recurrent vein is interstitial with the cross vein (in the above specimens the recurrent vein is well into the first submarginal)
        • I did not measure the specimen but Mitchell puts the size as 8mm (vs 4.5mm - 5mm for N. parva).

      If any one has or knows of 2 submarginal celled Nomada....we would love to borrow them.  Take a look through your N. parva collection...that was my initial impression of the species and the only other species of Nomada I have seen this small have been N. parva (possibly some small N. sayi) and what could be an undescribed bidentate species from the upper Midwest.

      Many Thanks


      Sam Droege  sdroege@...                      
      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

      Dear Math,
      Go solve your own problems.
      I am not finding your X!