Some notes on Eastern Nomada Identification and Status
Molly Rightmyer, Sean Brady, and Cory Sheffield have been busy extracting DNA from Nomada specimens over the past 2 years. Some of those specimens have come from members of this list (1000 Thanks for your help). Their work has been extremely useful and is just now ripe enough that some fruits can be plucked from their molecular trees. Below are some of my notes on a few groups in which molecular work has already helped clarify identification issues. This, however, is but the surface as there are quite a number of synonyonmys to be made and more species to be described. In some cases there are now more apparent molecular groups than there are species on the books. In particular, those groups that in the past have given us the most trouble while identifying species also have the most potential new species (unfortunately, some may be cryptic). The groups with the most head scratchers are the bidentate species (Gnathias in Mitchell's work), what we call the white-spined species (N. cressonii, pygmaea, sayi, etc.), the red-haired species (N. composita, valida, depressa, xanthura, etc.), and many odds and ends groups in need of male-female associations and name issues.
So, for those of you interested, some updates are listed below.... We would be particularly interested in any odd Nomada you run across and as Sean and I (Molly is now working on Osmia in Terry's Lab) will continue to work on North American species and I am going to guess the Cory and Laurence will be working on them in Canada, but it is clear that this will take us years to sort the group out.
For those of you are stuck with having to do identifications for papers. My suggestion (I do not speak for the group here) is to morpho-species the specimens for the time being and then send us examples so we can bar code them and over the years we will be able to help you put names on the specimens. Note that it will take us a long time to complete this as this is a side project for us.
More to come as the weeks progress.
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
"This isn't like naming your dog spot."
Richard Mellvill, Secretary, International Commission
on Zoological Nomenclature, on naming plants and animals.
MR_1 – Undescribed Species
Identification Summary: Note this is an undescribed species based on Molly Rightmyer's molecular work. A single tiny female (6mm) from the Poconos of NE Pennsylvania. Has 2 submarginal cell and those cell equally wide (unlike species with 3 submarginals that lose crossveins periodically); mandibles relatively long and slender; labral projection either absent or only vaguely there at the bottom rim; T2 with no apparent pits; hind tibia with setae long and white similar to the white spine group; clypeus, labrum, and paraocular area an orangish color rather than the normal yellow; supraclypeus with a dark red blotch; antennae unfortunately missing beyond F2; molecular analysis shows affiliations with some western Centrias species but molecular distance great and extremely distant from Eastern species
I think that Molly's work has finally convinced me that I really know N. dentariae, at least for the males.
The interesting thing is that it is not affiliated with Heminomada but with Centrias...but this makes sense in that I had in my notes and this specimen confirmed that its antennae was slightly sculptured and it had maculations on the sternites along with the inflated scape and tiny F1....
its also relatively small for a Heminomada
Below is an ID summary.
Identification Summary: An uncommon and tricky species. Mitchell lists it as affiliated with Heminomada group species such as N. imbricata and N. luteoloides however, from molecular analyses we now know it is affiliated with Centrias group species such as N. articulata and N. rubicunda. MALES told from other species with strongly striped abdomens by its inflated wide scape (olive shaped) with the pedicel recessed entrirely into the scape; the complete yellow bands on T2-6; F1 very short and F2 very long with the short side of F1 less than half the length of F2;Underside of F3-F11 flattened and very slightly concave (not as much as N. denticulata); sternites with variable but extensive yellow on them. Size-wise, relatively small, FEMALES: Not yet clear how to differentiate these.
N. articulata and N. australis
OK, it looks like the old color characters for N. articulata and N. australis males are not very useful...check out the characters below....based on a long series of specimens from the East as well as Cory's from Canada.
Males, N. articulata vs N. australis - Note that both these species have a sharp but small thorn-like spine projecting out from the underside of F3
N. australis - Orient the antennal segments so that the FLAT underside is facing down and you are looking at those segments with the OUTSIDE EDGE facing you, you will notice that the faces of the underside and the outside side form an edge and towards the distal portion of that edge the integument is pulled downward forming a sharp point something not quite as pointed as the spine on T3 but acute and noticable - Scutum ALWAYS black
N. articulata - Orient the antennal segements so that the FLAT underside is facing down and you are looking at those segments with the OUTSIDE EDGE facing you, you will notice that the faces of the underside and the outside side form an edge and towards the distal portion of that edge the integument is either not altered at all or only forms an obtuse rounded bump, nothing you would call remotely sharp - Scutum USUALLY with at least some red markings but SOMETIMES entirely black
MR_2 Glenn Hall’s Florida Specimen 2556
An interesting and distinct species. From Molly and Sean’s CO1 analysis this species plops right between N. affabilis and N. edwardsii yet appears to share few characteristics. For these 2 species have F1 > F2, are black with strong yellow maculations throughout, short mandibles, and are big bulky species with many hind tibial setae. MR_2 has none of these being red with no apparent maculations, hugely long mandibles, F2 > F1, and only a couple hind leg tibial setae.
This species has 2 very distinctive features. Its mandibles, which cross below the entire labrum, are so long (and quite thin) that the tips go stretch well beyond the opposite mandible’s base. The second unique feature is a pronotal collar with a humeral angle and ridge similar to some Andrena species, quite sharp and well defined. A moderately large specimen at 11mm in total length; gena quite distinctly carinate; head appears somewhat wider than normal; labral projection slightly below center; labrum with a few long reddish hairs, but those hairs do not extend to the clypeus or scape as in the traditional red-haired species; left hind tibia with 2 stout red setae that project slightly beyond the surrounding white hairs and the right with 3, there appear to be 2 additional, longer clear setae between the red ones and the triangular stubby spine on the corner of the apical end of the tibia; pseudopygidial area longitudinally greater than most species, somewhere between 1/3 and 1/2 the length of the segment, but of the normal setae characteristics and unlike those of N. depressa; black integument almost entirely absent restricted to very small spots on the scutum, rear face of the propodeum, base of antennae, middle coxae, and lateral dots on the pronotum; yellow maculations appear to be absent, however, there are suggestions of yellow in some of the usual spots on T2, mesepisturnum, collar, and antennae, however, other Hall specimens appear to be quite normal so no discoloration is suspected. Several obscure holotypes (particularly N. skinneri) are being pursued to double check that this is a new species, but their descriptions do not mention several key features of this species.
Also note that Molly’s specimens N18A9, N18H8, and N18G8 all from Turkey Run, VA match this species description except for the maculations are bright yellow, the mandibles are not quite as long, and the genetics come out in quite a different place. Hmmm.
Males of N. fragariae , N. imbricata, N. luteoloides, N. luteola, N. sulphuata
N. fragariae - UNIQUE in that the very apex of the upper, and much lighter colored, surface of the last segment of the antennae is approximately along the centerline of the segment or only slightly shifted towards the outside of that imaginary medial line, additionally there are 3-7 setae that project out from that surface beyond the tip that, while microscopic, are distinct under high power and much larger than the small, appressed hairs that dot the surface, in the other species the apex is shifted nearly to the outside edge of the antennae, although less extremely so in N. sulphurata, and there are no setae projecting beyond the tip - Entire sides of scutum usually with a narrow, but sometimes faint, border of yellow - Only N. imbricata also has yellow on the scutum and this is usually BUT NOT ALWAYS restricted to the sides of the scutum to the rear of the tegulae, rarely does it run the entire segment, the rest of these species have NO yellow on scutum - Length of flagellar segment 1 variable, but usually about half of 2 - Rear leg tibial setae 4-8, usually difficult to see as they blend into the hairs behind them, but UNIQUE in that they are evenly spaced out and follow the rim itself and are usually just a bit longer than the surrounding white hairs - Yellow on rear face of propodeum can vary from 0 - rare - to 3 separate sets of patches, usually there is one set above the hind coxae, one on the sides of the propodeal triangle, and then often a fainter one in between - The small round mound at the top of the mesepisternum usually with a very faint yellow mark, a yellow stripe in the center of the mesepisternum runs from the front to the rear - Upper surface of antennae yellow-brown
N. imbricata - Most often confused with N. luteoloides - Length of flagellar segment 1 clearly more than half of 2 - Rear leg tibial setae mostly 2-3 - Femur of the middle leg with hairs LESS than one quarter the width of the femur- Tends to come out later in the season than luteoloides - Can have small narrow strip of yellow along the sides of the scutum this often limited to the area to the rear of the tegula but can extend along the entire side or, also commonly, can be completely absent - The longitudinal width of the darkly translucent rim of T4 USUALLY, BUT NOT ALWAYS equal to or less than the width of the yellow stripe that runs from side to side behind it - Yellow on thorax can vary from none to extensive markings even on the scutum
N. luteola - Most often confused with N. sulphurata - Flagellar segment 1 half or less of 2 - Rear legs tibial setae mostly 5-7, these short, fat, and not extending beyond the nearby white hairs - Yellow on rear face of propodeum extensive and runs into the propodeal triangle, something that rarely happens on the other species - The small round mound at the top of the mesepisternum USUALLY completely yellow, usually with only a restricted amount in the other species or none at all - Upper surface of antennae brown to dark brown - In direct comparison the cheek far more stongly carinate than the other species
N. luteoloides - Most often confused with N. imbricata, length of flagellar segment 1 clearly more than half of 2 - Rear leg tibial setae mostly 2-3 - Hairs on bottom of the femur of the middle leg longer than one quarter of the width of the femur, this character the most consistent way to separate from N. imbricata - The dark transluscent rim of T4 longitudinally wider than the yellow stripe running from side to side just interior to the transluscent rim - Yellow on thorax can vary from none to extensive but never with yellow on the scutum
N. sulphurata - Most often confused with N. luteola, flagellar segment 1 half or less of 2, rear leg tibial setae mostly 5-7, stout, clear yellow, and usually just short in height of the surrounding white hairs, yellow on rear face of propodeum often restricted to yellow ovals above the rear coxa but also can have spots within the propodeal triangle - The small round mound at the top of the mesepisternum usually with an small oblong yellow mark, but that too can be variable - Upper surface of antennae nearly black
Females of N. affabilis, N. fragariae, N. luteoloides, N. luteola, N. sulphurata, N. imbricata
N. affabilis - Face above antennae with extensive red, usually more red than black, lower edge of cheek opaque and only slightly lipped, sides of propodeal triangle usually yellow, hind tibia setae with more than 10 setae and those setae yellow or clear - UNIQUE in that flagellar segment 1 longer than 2
N. fragariae - UNIQUE in that the rear face of the propodeum has ABSOLUTELY NO HAIR, the other species have copious, long hair on the segment - 4-6 hind tibial setae, these long, about the length of the surrounding white hairs and curved outward not over toward the side - In direct comparison with the other species the microscopic projecting hairs on the underside of the antennae, not the appressed minute ones on the surface, clearly longer
N. imbricata - Most often confused with N. luteoloides - Head and Thorax always with at least some red present, even in the darkest individuals - Lower edge of cheek opaque and only slightly lipped, or carinate - Told from N. luteolodies by sides of propodeal triangle invaded with yellow or red - Fewer than 5 setae on apex of hind tibia, setae STRONGLY bent sideways along the edge of the rim
N. luteola - Most often confused with N. sulphurata - Face usually extensively yellow and red - UNIQUE execpt for N. michenri in that the cheek carina or lip very wide and transparent, though dark in coloration - Propodeal triangle yellow on sides - Has more than than 10 short peg-like setae on hind tibia, usually more than N. sulphurata
N. luteoloides - Most often confused with N. imbricata - Southern populations usually strictly black with yellow markings, however, New England,Canadian, and Appalachian populations can have limited to extensive amounts of red on the head, thorax,and even the abdomen appearly closer to N. imbricata in coloration - Lower edge of cheek opaque and only slightly lipped - Told from N. imbricata by propodial triangle being ALL black - Rear tibia with fewer than 5 setae, setae STRONGLY curved to the side
N. micheneri - We haven't seen any specimens of this species and the male has not been described so urge caution in making determinations, and urge you to send possible specimens to us for verification - Face black - Edge of cheek transparent, thin, and wide - Propodial triangle sides yellow - Fewer than 10 straight setae
N. sulphurata - Most often confused with N. luteola - Face usually without black marknigs but can have extensive black or red - Cheek carina or lip small and opaque - Propodeal triangle yellow on sides - Hind tibia can have more than or fewer than 10 peg like, straight setae
Identification Summary: This is one of only 2 eastern species that have only 2 submarginal cells (The other is the undescribed species MR_1 and is very tiny and the other on the books we will be synonomyzing). Further to the west a closely related but molecularly distinct sister species has 3 cells. In N. obliterata the 2 cell situation is clearly caused by the simple loss of the first transcubital vein.
P Bees are not optional.