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Dieunomia guide updated

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  • Michael Orr
    Hello all, This guide has been extended to include six Western species in addition to the three Eastern species for which there was already a guide, this made
    Message 1 of 1 , May 9, 2011
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      Hello all,


      This guide has been extended to include six Western species in addition to the three Eastern species for which there was already a guide, this made possible through the loans of the Logan lab and the AMNH. Due to the degree of dissimilarity between the subspecies D. heteropoda heteropoda and D. heteropoda kirbii, it was decided that the two would be scored differently in the guides, resulting in both D. heteropoda heteropoda and D. heteropoda kirbii being represented in the guide. The Southwestern species D. mesillae is another point of interest. Described by Cockerell in 1899, this species is apparently only known from male specimens, which led Cockerell in 1935 to suggest that it is likely the male of D. apacha, a view which I share upon examination of the type and a series of D. apacha males. If you have any information suggesting otherwise, however, it would be greatly appreciated.

      The guide may be found here:
      http://www.discoverlife.org/mp/20q?guide=Dieunomia

      For convenience's sake, here are all the characters from the guide with their scorings:
      Male, Abdomen, T3, form of integument at middle of segment
      With a rear-facing, angular protrusion arising from the basal limits of the apical impressed area of the rim, this protrusion extends at least partially over the apically impressed rim (apacha, mesillae)
      Basal limit of the apical impressed area straight, smoothly convex, or nearly so at the latitudinal center of the segment (heteropoda, heteropoda kirbii, micheneri, nevadensis, triangulifera, xerophila)

      Thorax, tegula, integumental color
      Bright reddish-orange and almost entirely transparent (apacha, bolliana, heteropoda, heteropoda kirbii, mesillae, micheneri, nevadensis, xerophila)
      A darker, duller brown color, which often gives the tegula a much more opaque appearance (heteropoda, heteropoda kirbii, micheneri, triangulifera, xerophila)

      D. heteropoda heteropoda vs other species - Note that this guide does not group D. heteropoda h. and D. heteropoda kirbii together
      D. heteropoda h. - Thorax entirely darkly pubescent, although some hair may seem to be a slightly lighter brown at the pronotal lobes and mesepisternum, these areas sometimes a brownish color in the males - Wings strongly darkened throughout - With only dark hairs on the tergites, and no light-colored apical hair bands present - Very large species, reaching up to 20mm in length
      Other species - Thorax hair color primarily, if not entirely, a light white to yellow color - Wings only dark brownish only at the tips, if at all - With light-colored apical hair bands, and often light-colored hairs outside of the apical hair bands as well - Size variable, although D. apacha, D. mesillae, and D. xerophila approach 20mm no specimens have been seen equal to the largest of D. heteropoda

      Male, thorax, scutellum, pitting pattern
      Pit density becoming very sparse on two slightly-produced bumps which occur one to each side of the midline, this made especially noticeable by the distinct lack of hair in the area (micheneri, nevadensis, triangulifera)
      Pit density relatively uniform throughout, if with any unpitted areas then they are very small and only equal in diameter to a couple pit diameters, although often the area is obscured by much denser hair than is found in those other species with sparsely pitted bumps (apacha, bolliana, heteropoda, heteropoda kirbii, mesillae, xerophila)

      Female, thorax, scutellum, pitting pattern
      Pit density becoming very sparse on two slightly-produced bumps which occur one to each side of the midline, this made especially noticeable by the distinct lack of hair in the area (bolliana, micheneri, nevadensis, triangulifera)
      Pit density relatively uniform throughout, although often the area is obscured by much denser hair than is found in those other species with sparsely pitted bumps (apacha, bolliana, heteropoda, heteropoda kirbii, nevadensis, triangulifera, xerophila)

      Male, abdomen, T1, integumental color
      With strong reddish-orange coloration at least in the basal half, although more often throughout all of T1 (micheneri, nevadensis)
      Entirely black or brown, although the brown may sometimes seem slightly reddened (apacha, bolliana, heteropoda, heteropoda kirbii, mesillae, micheneri, nevadensis, triangulifera, xerophila)

      Male, D. triangulifera vs other species
      D. triangulifera - Pitting at the top of the compound eye exceptionally dense, with most pits nearly touching and no pit interspaces nearing one pit diameter in size - Rear face of propodeum very roughened throughout, appearing dulled overall as a result, with pit interspaces ranging from nearly touching to over one pit diameter
      Other species - Pitting at the top of the compound eye variable, but almost always with at least a few pit interspaces nearing one pit diameter - Rear face of propodeum is most often sparsely pitted and the surface appears evenly smooth and shiny throughout, although in D. heteropoda they may sometimes be coarse and dense

      Male, thorax, dorsal propodeal enclosure, surface sculpturing
      With straight or nearly-straight striations, although they may not be oriented directly parallel with the longitudinal axis, reaching from the anterior to the posterior edges of the enclosure or nearly so  (bolliana, micheneri, nevadensis)
      Jagged and non-linearly striate, this patterning NOT forming any kind of secondary enclosures within the dorsal propodeal enclosure (bolliana, mesillae, micheneri, nevadensis, triangulifera)
      Highly-irregular and non-linearly reticulate, this patterning forming a number of smaller circular or non-circular enclosures within the dorsal propodeal enclosure (apacha, heteropoda, heteropoda kirbii, mesillae, triangulifera, xerophila)
      Patterning extremely weak, both thin and shorter than half the longitudinal length of the propodeal triangle, essentially impossible to judge based upon the criteria here - NOTE, do not score for this state if your specimen cannot be scored for other states due to debris or other factors that may make it hard to see the character (nevadensis)

      Female, scutum, pitting
      Pitting dense anteriorly, with at least some pits nearly touching, but sparser posteriorly where the pit interspaces exceed the pit diameters at least in part (apacha, micheneri, nevadensis, triangulifera)
      Pitting dense anteriorly, with at least some pits nearly touching, and equally dense in the posterior half of the scutum, if sparser here then only very slightly (bolliana, heteropoda, heteropoda kirbii, nevadensis, triangulifera, xerophila)

      Male, head, position of lateral ocelli
      Nearer to eyes than vertex margin (apacha, bolliana, mesillae, micheneri, triangulifera)
      Nearer to vertex margin than eyes (heteropoda, heteropoda kirbii, nevadensis)
      Roughly the same distance from the eyes and vertex margin (apacha, heteropoda, heteropoda kirbii, mesillae, triangulifera, xerophila)

      Female, T5, hair color
      Primarily dark, at least in the apical half, black or dark brownish (apacha, heteropoda, heteropoda kirbii, triangulifera, xerophila)
      Nearly all light, white, yellow, or light brownish, although sometimes the hairs are slightly darkened just along the rim (apacha, bolliana, micheneri, nevadensis)

      Male, head, vertex, pitting posterolateral to the lateral ocelli
      Pitting sparse, with pit interspaces equal to or nearing one pit diameter, the pitting here clearly less dense than at the center of the vertex (heteropoda, heteropoda kirbii, micheneri, nevadensis, xerophila)
      Pitting dense, with few if any pit interspaces nearing one pit diameter, the pitting here similar to that at the center of the vertex (apacha, bolliana, heteropoda, heteropoda kirbii, mesillae, micheneri, nevadensis, triangulifera)

      Male, head, antennae, F11
      Tip strongly flattened into a lobe-like structure, usually wider than the diameter at the center of the segment (apacha, bolliana, heteropoda, heteropoda kirbii, mesillae, xerophila)
      Tip weakly flattened, if at all, with the widest point of the segment usually near its middle, giving it the appearance of a fingertip in profile (micheneri, nevadensis, triangulifera)

      Male, hindleg, tibia, outline of apical structure in profile
      Structure simplistic and pointed, with one apical spike present, the base of the spike straight or nearly so in its length (micheneri, triangulifera)
      Structure relatively simplistic and pointed apically, with one spike here, although there is also a bump present near the middle of the tibia (micheneri, nevadensis)
      Structure with a small spike near the apex of the tibia as well as a large lobe basal to it (bolliana)
      Structure very large and bulbous apically, not pointed but instead with a large lobe that may or may not have two distinct points near its tip, usually has a slight bump in the basal half of the tibia as well (apacha, mesillae)
      Structure very large and bulbous apically, not pointed but instead with a large lobe that has a clear groove indented along its tip which is visible from the side, as well as a distinct bump in the basal half of the tibia and an inward-projecting spike near the tip (heteropoda, hetereopoda kirbii, xerophila)

      Male, D. heteropoda kirbii vs D. xerophila
      D. heteropoda kirbii - The level of emargination of the bottom of the midfemur seems about equal when viewing the midfemur from the side and when it is viewed slightly ventrally from this original position
      D. xerophila - The level of emargination becomes dramatically more apparent when viewing the midfemur from a slightly ventral view, after having been looking at the outside face of the midfemur in a side view, this due to the tip of the distal side of the emargination being slightly set back from the outside face of the midfemur such that it is not visible from a straight side view

      Male, D. micheneri vs D. nevadensis
      D. micheneri - Tibia of hindleg with only a very gradual and slightly-elevated bump near the middle of the inner surface, if any such bump present at all - The concave portion of T1 very gradually transitions into the lateral sides of T1, making it effectively impossible to distinguish where the concave area ends laterally - NEVER with extensive reddening of T3 - In direct comparison, larger - Limited in its distribution to Mexico and those states bordering it to the North
      D. nevadensis - Tibia of hindleg with a distinct, and most often protruding obtusely angled bump about halfway down the length of the tibia - The concave area of T1 is well defined laterally, such that it is possible to tell where this area ends laterally, although it may sometimes appear only weakly defined - Often with extensive reddening of T3, at least in the Southwest - In direct comparison, smaller - Relatively widespread in the Southern and Western US, reaching as far East as Florida - NOTE that while it is the Southwestern D. nevadensis arizonensis which has the most extensive reddening and shares its range with D. micheneri, other forms have been seen to be much darker in their integumental coloration

      Female, thorax, scutum, form of hair
      Hair primarily short, less than half the length of that found on the mesepisternum, although there are sometimes longer hairs mixed in sparsely - Hairs heavily branched, usually well obscuring surface (apacha, bolliana, heteropoda, heteropoda kirbii, xerophila)
      Hairs a mixture of long and short hairs, neither length obviously dominant - Hairs less heavily branched, with the surface below usually mostly visible (micheneri, nevadensis, triangulifera)

      Female, thorax, longitudinal length of sculpted portion of propodeum at the middle vs the longitudinal length of the metanotum at the middle
      Metanotum shorter (apacha, heteropoda, heteropoda kirbii, xerophila)
      Metanotum about equal (apacha, nevadensis, xerophila)
      Metanotum longer (bolliana, micheneri, nevadensis, triangulifera)

      Female, thorax, propodeum, shape of the posterior edge of the impressed area found basally on the dorsum of the propodeum - NOTE that the impressed area will terminate at or before the turn from the dorsal to rear face of the propodeum, if it does not then you are likely looking at the edge of the propodeal triangle rather than the impressed area
      Edge convex, appearing evenly rounded or nearly so (bolliana, heteropoda, heteropoda kirbii, nevadensis, xerophila)
      Edge concave, appearing wider laterally, with the longitudinal length of the impressed area constricted medially (micheneri, nevadensis, triangulifera)
      Edge straight for half its total latitudinal width or more (apacha, heteropoda kirbii, nevadensis,  triangulifera)
      Edge very weakly developed, sometimes completely absent, this state often accompanied by similarly weakened sculpturing that may be constrained only to the basal half of the dorsal face of the propodeum (micheneri, nevadensis)

      Female, D. apacha vs other species - NOTE that D. mesillae very likely fulfills the same description for D. apacha, although this has not been confirmed due to a lack of specimens
      D. apacha - Outer face of the midtibia largely darkly pubescent, though with a distinct area of lighter hair basally - The impressed area of T1 has extremely variable pitting, ranging from nearly touching to well over one pit diameter in spacing - Hindfemur with a touch of dark brownish to black hairs present in the apical brush, present just before the basitibial plate - Hindtibial scopa with a clear dark stripe extending from the basitibial plate to the end of the tibia, or nearly so, with the rest of the scopal hairs appearing off-white or yellowish
      Other species - Outer face of the midtibia either entirely dark or light pubescent, or if mixed then primarily light and with only weakly darkened areas - Pitting of T1 variable among species, but rarely ever as variable within a single specimen as it is in D. apacha - Hindfemur with either only light colors in the apical brush of hairs just before the basitibial plate, or with all hair dark instead of just those of the brush itself - Hindtibial scopa with either all dark hairs or all light hairs, the latter condition sometimes accompanied by a small dark stripe similar to that of D. apacha, although it is limited to the basal half of the tibia

      Female, D. micheneri vs D. nevadensis
      D. micheneri - Clypeal rim dentate, with a pair of small teeth located medially, best viewed either by removing hairs or by angling the head upside-down and looking in at the clypeal rim from the side
      D. nevadensis - Clypeal rim straight or smoothly convex, lacking a medial pair of teeth

      Female, D. apacha vs D. xerophila
      D. apacha - The tegulae are a clearly transparent orangish color - The vertical tip of the propodeal triangle is smooth and somewhat shiny, with very weak transverse striations if any are present - The black stripe of hairs found along the dorsal side of the scopa is thinner, usually restricted only to the top and sometimes barely into the outside face of the tibia
      D. xerophila - On average, the tegulae are usually a much darker opaque brownish color, although sometimes they may seem orangish as is seen in D. apacha - The vertical tip of the propodeal triangle is heavily roughened, often with clear transverse striations - The black stripe of hairs found along the dorsal side of the scopa is wider, darker hairs usually present up to halfway down both the inside and outside face of the tibia

      Female, D. mesillae vs other species
      D. mesillae - This is a rarely reported bee of the Southwest US, the male of which VERY closely resembles D. apacha to the extent that Cockerell has suggested that the male type of D. mesillae may simply be a male of D. apacha - Specimens should be considered D. apacha until a more thorough revision is complete for the group
      Other species, including D. apacha

      If you've read over the characters and found anything questionable, or have any suggestions for either diction changes or additional characters, please contact either myself (mco25@...) or Sam Droege (sdroege@...). We only have so many specimens of each species available to us, so we always welcome any user feedback that might benefit the resolving power or clarity of the guides.


      -Michael Orr
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