Nomada texana Cresson, 1872
  Apoidea   Apidae   Nomada
Subgenus: None

Nomada texana, male, face 2012-08-09-17.08.11 ZS PMax
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Nomada texana, male, face 2012-08-09-17.08.11 ZS PMax

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Nomada texana, male, side 2012-08-09-17.17.03 ZS PMax
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Nomada texana, male, side 2012-08-09-17.17.03 ZS PMax

Nomada texana, male, back 2012-08-09-17
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Nomada texana, male, back 2012-08-09-17

Nomada texana, Texas Nomad Bee
© Copyright John Ascher, 2006-2014 · 6
Nomada texana, Texas Nomad Bee

Nomada texana, Texas Nomad Bee
© Copyright John Ascher, 2006-2014 · 6
Nomada texana, Texas Nomad Bee

Nomada texana, Texas Nomad Bee
© Copyright John Ascher, 2006-2014 · 6
Nomada texana, Texas Nomad Bee
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Reprinted with permission from: Mitchell, T.B. 1962 Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 152.

FEMALE—Length 8-9 mm.; lateral ocelli slightly nearer margin of vertex than to each other; cheeks very narrow, less than half width of eyes; shorter side of basal segment flagellum fully as long as segment 2, median segments about as long as broad; mandibles slender and simple; wings subhyaline basally, becoming rather deeply infuscated at apex and in region of marginal cell, 2nd submarginal very broad anteriorly, 3rd much narrower, veins piceous, stigma more testaceous, basal vein interstitial with transverse median; tegulae shining between minute and quite sparse punctures; posterior margin of scutellum slightly grooved medially; front coxal spines slender and elongate, rather densely pubescent; apex of hind tibiae with a row short, yellowish, apically dilated setae; head including clypeus, largely black, face with broad, extensive, yellow maculations filling space between antennae, supraclypeal area and eye, extending from clypeus nearly to top eye, and a narrow yellow band bordering margin of eye on cheeks above; mandibles yellow at base, becoming more testaceous medially, fuscous at tip, labrum entirely testaceous; scape, pedicel and base of flagellum testaceous, the more apical flagellar segments more brownish; pronotal collar, tubercles, tegulae, scutellum in large part, adjacent median area metanotum, and a rather broad, transverse stripe on pleura, bright yellow; scutellum with black median line and anterior margin narrowly black; legs testaceous in large part, spurs pale yellow, and hind tibiae with a small yellow apical maculation; abdominal terga 1-5 with entire, transverse, subapical, yellow bands, those on 2 and 3 much narrowed medially but very broad laterally, band on 4 less restricted medially, and that on 5 quite deeply constricted; abdominal sterna 1 and 2 entirely dark, 3 and 4 with conspicuous, transverse, yellow bands; punctures of face above coarse, close, deep and distinct, becoming more sparse laterally and below, quite close but somewhat finer on supraclypeal area, very irregular and scattered on the shining clypeus, rather fine and close on vertex and on cheeks above, becoming coarser and deeper on cheeks below; scutum and scutellum coarsely rugoso-punctate, punctures very coarse and slightly separated on pleura below, becoming somewhat finer and crowded above, finer but deep and distinct on metapleura; lateral faces of propodeum densely rugose in part, but with a shining, punctate space below, the punctures rather sparse, posterior face quite deeply, closely and distinctly punctate, triangle impunctate, somewhat shining; basal addominal tergum shining, punctures toward base exceedingly minute and rather close, becoming somewhat deeper, more distinct and more widely separated in the yellow band, minute and scattered toward the rim; terga 2-5 very uniformly, closely, deeply and finely punctate, punctures becoming somewhat finer toward the narrowly impunctate rims; pseudopygidium rather extensive, median length about half the breadth, narrowly truncate apically, covered with short, dense, yellowish tomentum; pubescence extremely short, thin and obscure, entirely pale where visible.

MALE—Length 7-10 mm.; lateral ocelli subequally distant from margin of vertex and each other; cheeks about half width of eyes; shorter side of basal segment of flagellum fully equal to segment 2, median segments slightly broader than long; mandibles slender and simple; wings subhyaline at base, becoming quite deeply infuscated apically, with the usual three submarginal cells, 2nd broad anteriorly, 3rd quite strongly narrowed, veins piceous, stigma more testaceous, basal vein interstitial with transverse median; tegulae shining between minute, sparse punctures; posterior margin of scutellum slightly grooved medially; front coxal spines slender and elongate, rather densely pubescent; hind femora unmodified; lower half of face, including labrum and basal half of mandibles, largely yellow, upper half of supraclypeal area black, the lateral yellow maculae terminating acutely at upper end of eye, cheeks with a narrow yellow maculation bordering eye above; antennal scape bright yellow anteriorly, the if flagellum brownish-testaceous below, becoming more piceous above; pronotal collar, tubercles, tegulae, scutellum except anterior margin and mid-line, adjacent median area of metanotum, and a transverse band on pleura bright yellow; legs largely testaceous, spurs pale yellow, mid and hind tibiae with yellow apical maculations, and hind basitarsi yellow in part; punctures of face above coarse, deep and distinct, only slightly separated, becoming somewhat less coarse and more widely separated below, irregular and variable as to size on clypeus, somewhat finer and close on vertex and cheeks above, becoming slightly coarser below; scutum and scutellum quite coarsely rugoso-punctate, punctures of pleura below very coarse, deep and slightly separated, becoming quite densely crowded above; propodeum laterally dull, with variable, very fine and shallow punctures, posterior face with somewhat closer and deeper punctures, triangle entirely impunctate, somewhat shining; basal abdominal tergum shining, punctures minute and quite close toward base, becoming somewhat more coarse and sparse on the transverse yellow band; terga 2-6 with uniformly close, deep and rather coarse punctures throughout, these becoming somewhat finer toward the narrowly impunctate rims, these somewhat reddened on the more apical terga; pubescence very short, thin and obscure, entirely white where visible; basal width of pygidial plate about equal to median length, slightly narrowed apically, apex slightly incised or emarginate, margins carinate, surface minutely and closely punctate basally, punctures becoming obscure apically; sternum 8 as in modesta (fig. 101); gonocoxites of genital armature similar to those of heiligbrodtii (fig. 99), the gonostyli very short.

DISTRIBUTION—Michigan to Massachusetts, south to Texas and Alabama, July to September.

FLOWER RECORDS—Helianthus, Marilaundium and Verbesina. This species has been recorded by Robertson (1929) on Cephalanthus, Eryngium, Pycnanthemum and Verbena.

Extracted from SAM DROEGE, MOLLY G. RIGHTMYER, CORY S. SHEFFIELD & SEÁN G. BRADY 2010. New synonymies in the bee genus Nomada from North America (Hymenoptera: Apidae). Zootaxa, 2661: 1-32.

Diagnosis. Nomada texana is most similar to N. tiftonensis, but can be differentiated from the latter species by the following characters: in both males and females, S3 and S4 each has a narrow, ivory or very pale yellow, transverse maculation that medially curves slightly anteriorly. The maculations are slightly interrupted medially or nearly so, and one observed specimen from Texas has maculations restricted to small areas laterally on S3 and S4. In contrast, in N. tiftonensis there are no maculations on any of the metasomal sterna. Also, in both males and females of N. texana on T3 there is an uninterrupted, yellow or ivory, transverse maculation (Fig. 43), while in N. tiftonensis the maculation on this tergum is widely medially interrupted (Fig. 44); however, there is often a faint area of paler brown integument connecting the two lateral yellow maculations, and in one specimen from Ontario the maculation is entirely uninterrupted. Females of the two species can be differentiated by characters of the hind tibia (viewed at high magnification): in N. texana, there are three to five, very wide and flat, transparent white to brownish, spine-like hairs (depending on the light reflection) whose apical tips are squared-off and extend only to the same length as, or slightly further than, the surrounding finer, white hairs (Fig. 35); while in N. tiftonensis these specialized hairs number from seven to ten, increase more dramatically in size posteriorly along the apical margin, and are clearly longer than the surrounding, finer, white hairs; these hairs comparatively thinner than those of N. texana (though still thicker than in many other Nomada species), round in cross-section, and translucent yellow throughout most of their length but at least a few of the longest and posterior-most hairs have the bases translucent white and the apical tips opaque brown to dark red (Fig. 37). Females of N. texana and N. tiftonensis can additionally be separated by the punctation of the clypeus relative to the paraocular area: in N. texana the punctures on the clypeus are distinctly smaller and denser than those on the paraocular area (punctures ranging in size from relatively small to large, Fig. 39), while in N. tiftonensis the punctures are almost exactly the same size and density on the clypeus as in the yellow portion of the paraocular area (punctures uniformly large, Fig. 40). Males of the two species are not as distinctly separated by the punctures of the clypeus, but in general the punctures are denser in N. texana than in N. tiftonensis (with significant overlap between the two species).

Males and females of N. texana and N. tiftonensis generally differ, sometimes subtly, in features of the antenna: the antenna (especially the scape, pedicel, and F1) is comparatively brighter yellow-orange in N. texana than in N. tiftonensis, with the antenna of most N. tiftonensis specimens dark brown with black on the posterior surface (when antennae directed dorsally) and dull orange markings on the anterior surfaces of the scape, pedicel and F1 (antenna of N. texana with much less contrast between the anterior and posterior surfaces). As discussed above, the density of punctures on the clypeus tends to be much lower in females of N. tiftonensis than in N. texana (length of space between punctures often greater than one puncture diameter in N. tiftonensis, spaces between punctures rarely greater than a puncture diameter in N. texana), although in both species there is sometimes an impunctate longitudinal line at the center of the clypeus (this impunctate line sometimes very broad in N. tiftonensis). The metasomal maculations of several specimens of N. texana are clearly ivory and most are pale yellow to near ivory, while in N. tiftonensis the maculations are entirely yellow. All observed specimens of N. tiftonensis have extensive amounts of black integument on the hind coxa, while in N. texana all but a few lack black integumental color and are instead entirely orange except for a yellow maculation present in both species; however, in a few specimens of N. texana there is a limited amount of black at the very base of the hind coxa and in the Maryland specimen the hind coxa is almost entirely black, except for dark orange shadings on the ventral surface.

Molecular results. We do not have molecular data from representatives of N. texana. Several specimens were sequenced that had previously been identified as N. texana, but upon closer examination they are in fact representatives of N. tiftonensis (see below).

Variation. Both of these very similar species have relatively low degrees of variability in most character states. In addition to the information presented in the description section, the extent of yellow/ivory on the male supraclypeal area varies in N. texana with all male specimens having pale maculations on the supraclypeal area, although the extent varies to a small degree.

Distribution. Nomada texana has a more southern and western distribution relative to N. tiftonensis, with specimens seen from Arizona and Idaho east to Texas and Indiana; we have also seen specimens from Georgia, Alabama, and Maryland.

Material examined. 35 specimens were examined from TX, ID, UT, NM, NE, GA, AL, NV, AZ, MD, and IN (Appendix).

Comments. Mitchell (1962) synonymized N. tiftonensis and N. modesta rivertonensis with N. heiligbrodtii, and then separated N. texana from N. heiligbrodtii based on the maculation pattern of T2 and T3. Based on the characters presented herein we disagree with his conclusions and instead believe that N. tiftonensis and N. modesta rivertonensis represent males and females of the same species, and that N. heiligbrodtii is a junior synonym of N. texana. Mitchell's (1962) keys to the males and females of Nomada, as well as diversity of names present on previously identified specimens in collections, reflect the general confusion between these two very similar species. Based on the available material, N. tiftonensis appears to inhabit eastern sandy areas; all of the collection locales represented by the material, with which we are familiar, meet that general description. With the exception of the Maryland specimen, we are not familiar with the collection locales represented by the examined N. texana specimens and are therefore unable to comment upon them. However, the Maryland specimen is perhaps illuminating in that it was captured only a few miles from specimens of N. tiftonensis.The soils of the capture site were silty clay soils (the region is famous for its bricks) while the N. tiftonensis specimens were captured in a restricted deep sand area along the Patuxent River (the only source of commercial sand in the region). It would be interesting to investigate the differences in the preferred sites. Hosts for both species are unknown.

Scientific source:

Supported by
Hosts · map
FamilyScientific name @ source (records)
Apiaceae  Daucus carota @ BBSL (2)
Apocynaceae  Asclepias @ AMNH_BEE (6)
Asclepiadaceae  Asclepias syriaca @ BBSL (1)
Asteraceae  Baccharis glutinosa @ AMNH_BEE (16)

Baccharis @ AMNH_BEE (11)

Helianthus annuus @ BBSL (1)

Helianthus @ AMNH_BEE (3)

Heterotheca subaxillaris @ AMNH_BEE (1)

Verbesina encelioides @ I_JSA (3); AMNH_BEE (4)
Fabaceae  Melilotus alba @ BBSL (6)

Melilotus officinalis @ BBSL (2); AMNH_BEE (85)

Prosopis @ AMNH_BEE (1)
Solanaceae  Chamaesaracha conoides @ AMNH_BEE (3)
Tamaricaceae  Tamarix sp @ BBSL (1)
_  Withheld @ BBSL (2)

Updated: 2020-04-02 07:35:47 gmt
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