Epeolus novomexicanus Cockerell, 1912

Onuferko, Thomas M., 2018, A revision of the cleptoparasitic bee genus Epeolus Latreille for Nearctic species, north of Mexico (Hymenoptera, Apidae), ZooKeys 755, pp. 1-185 : 122-126

35. Epeolus novomexicanus Cockerell, 1912 Figs 73, 74, 97E, 99B

Epeolus novomexicanus Cockerell, 1912. Ann. Mag. Nat. Hist. (8) 10: 487 (♂).

Diagnosis.

The following morphological features in combination (excluding any that are specific to the opposite sex of the one being diagnosed) can be used to tell E. novomexicanus apart from all other North American Epeolus except E. basili , E. nebulosus , and E. pusillus : the axilla is large, with the tip extending well beyond the midlength of the mesoscutellum but at most to the band of pale tomentum along its posterior margin, dilated laterally, and ferruginous to some degree whereas the mesoscutellum is typically all black; the axilla’s free portion is clearly less than 2/5 as long as its entire medial length; the mesopleuron is closely (most i<1d) and evenly punctate, that of the female is obscured by white tomentum only in the upper half (with a large, sparsely hairy circle occupying much of the ventrolateral half) whereas that of the male (excluding the hypoepimeral area) is entirely obscured by white tomentum; T2-T4 have complete and evenly broad fasciae; the T2 fascia has lobe-like anterolateral extensions of tomentum; and the pseudopygidial area of the female is lunate and wider than long (the apex ≤2 × the medial length). Epeolus basili , E. nebulosus , E. novomexicanus , and E. pusillus are all extremely similar to one another. Epeolus novomexicanus is most similar to E. nebulosus , but in E. nebulosus the mesoscutum is entirely obscured by pale tomentum and the metasomal terga (excluding the brown translucent apical margins) are entirely black whereas in E. novomexicanus the mesoscutum usually has distinct paramedian bands and at least the integument beneath the T1 apical fascia is ferruginous, as are sometimes the rest of the tergum and other terga. In E. basili the metasomal terga are also ferruginous to some degree, but the T2 and T3 (for female) or T2-T4 (for male) fasciae are narrowed medially and removed from the apical margin (in E. novomexicanus the T2-T4 fasciae are on or very little removed from the apical margin), and the pseudopygidial area of the female is ≥2 × the medial length. Whereas in E. pusillus the flagellum, except sometimes F1, and metasomal sterna are consistently brown or black and clearly not the same reddish-orange color as the legs (tibiae to tarsi), in E. novomexicanus the flagellum, at least ventrally, is the same reddish-orange color as the legs (tibiae to tarsi) as are usually the metasomal sterna. Epeolus novomexicanus is also similar to E. scutellaris in that the axilla is large, with the lateral margin arcuate, and that the apical fasciae are complete. However, in E. scutellaris the pseudopygidial area of the female is much wider (the apex ~2.5-3 × the medial length) than in E. novomexicanus , and the mesopleuron of both the female and male is obscured by white tomentum only in the upper half (with a large, sparsely hairy circle occupying much of the ventrolateral half).

Redescription.

MALE: Length 6.1 mm; head length 1.7 mm; head width 2.3 mm; fore wing length 4.4 mm.

Integument coloration. Mostly black; notable exceptions as follows: at least partially ferruginous on mandible, labrum, antenna, pronotal lobe, tegula, axilla, legs, metasomal terga (including pygidial plate), and metasomal sterna. Mandible with apex darker than rest of mandible; preapical tooth slightly lighter than mandibular apex (difficult to see in holotype because mandible closed; described from non-type specimens). Antenna brown and orange in part. Pronotal lobe and tegula pale ferruginous to amber. Wing membrane subhyaline, apically dusky. Legs more extensively reddish orange than brown or black. S1-S6 reddish orange.

Pubescence. Face with tomentum partly rubbed off in holotype, but white and densest around antennal socket in non-type specimens. Tomentum slightly sparser on clypeus; upper paraocular and frontal areas, and vertexal area mostly exposed. Dorsum of mesosoma and metasoma with bands of off-white to pale yellow short appressed setae. Mesoscutum with paramedian band partly obscured by surrounding pale tomentum. Mesopleuron (excluding hypoepimeral area) entirely obscured by white tomentum (except where rubbed off in holotype). Metanotum with tomentum uninterrupted, uniformly off white. T1 with narrow and short discal patch partly obscured by pale tomentum. T2-T5 each with complete fascia (T6 mostly retracted in holotype, but with complete fascia in non-type specimens), T2 with fascia with wide basomedially convergent anterolateral extensions of tomentum. S4 and S5 with long coppery to silvery subapical hairs, which individually are often darker apically.

Surface sculpture. Punctures dense. Labrum with larger and sparser punctures (i=1-2d) than clypeus (i<1d). Small impunctate shiny spot lateral to lateral ocellus. Mesoscutum, mesoscutellum, and axilla coarsely and densely rugose-punctate. Tegula densely punctate (i≤2d). Mesopleuron with ventrolateral half densely punctate (i<1d) to rugose; mesopleuron with punctures more or less equally dense throughout. Metasomal terga with punctures very fine, dense (i≈1d), evenly distributed on disc.

Structure. Preapical tooth obtuse. Labrum with pair of small subapical denticles not preceded by carinae. Frontal keel not strongly raised. Scape with greatest length 1.8 × greatest width. F2 as long as wide (L/W ratio = 1.0). Preoccipital ridge not joining hypostomal carina, from which it is separated by no less than 1 MOD at its terminal. Mesoscutellum weakly bigibbous. Axilla large, its lateral margin (L) half as long as mesoscutellar width (W) (L/W ratio = 0.5) and tip extending well beyond midlength of mesoscutellum but not as far back as its posterior margin; axilla with tip clearly visible, but unattached to mesoscutellum for less than 2/5 the medial length of axilla; axilla with lateral margin arcuate. Fore wing with three submarginal cells. Pygidial plate apically rounded, with large deep punctures closely clustered.

FEMALE: Description as for male except for usual secondary sexual characters and as follows: F2 noticeably longer than wide (L/W ratio = 1.5); mesopleuron densely hairy, except for two sparsely hairy circular patches (one behind pronotal lobe, a larger one occupying much of ventrolateral half of mesopleuron); T5 with large, continuous patch of pale tomentum bordering and contacting pseudopygidial area present only in female; T5 with pseudopygidial area lunate, its apex less than twice as wide as medial length, indicated by silvery setae on impressed disc of apicomedial region elevated from rest of tergum; S4 and S5 with much shorter hairs (S5 with apical fimbria of coppery to silvery hairs extending beyond apex of sternum by ~1/3 MOD); pygidial plate apically truncate, with small, denser punctures.

Distribution.

Western North America (Fig. 74).

Ecology.

HOST RECORDS: Torchio (1965) reported an association between E. pusillus (identified as such by R. Brumley) and C. ciliatoides Stephen (identified as such by W. Stephen, who in 1954 described the species) based on observations of females of the former entering the nests of females of the latter from an aggregation near Delta, Utah, USA. Brumley (1965) noted that a series of E. pusillus specimens taken from the Great Basin (primarily Utah) differed from other members of that species in having a reddish orange labrum, clypeus, antenna, mesopleuron, and metasomal terga and/or sterna; broader metasomal fasciae; and often denser pubescence on the mesoscutum. Herein, specimens matching that description are recognized as a separate albeit closely-related species, E. novomexicanus , which Brumley (1965) considered to be synonymous with E. crucis , a name herein synonymized under E. compactus .

FLORAL RECORDS: Labels of examined voucher specimens indicate floral associations with Chrysothamnus (possibly in reference to plants that now are in the genus Ericameria ), Erigeron L., Haplopappus Cass. ( Compositae ), Helianthus , Lupinus L. ( Leguminosae ), Machaeranthera Nees ( Compositae ), and Senecio spartioides Torr. & A. Gray.

Discussion.

Brumley (1965) considered E. novomexicanus and E. rufulus to be synonyms of E. crucis , a name which herein is recognized as a synonym of E. compactus . Here, E. novomexicanus and E. rufulus are considered to be valid names associated with two very different species, with the former most closely resembling E. basili , E. nebulosus , and E. pusillus . Although sequenced specimens of E. novomexicanus and E. pusillus share the same BIN, and were previously all regarded as E. pusillus ( Onuferko 2017), the difference in coloration and pubescence between the two forms is as pronounced as, if not more than, that between the true E. pusillus and sequenced representatives of the two members of the "pusillus group" ( E. basili and E. nebulosus ) that were assigned separate BINs. Hence, with strong molecular support for partitioning this species group into three distinct clusters in which four distinct forms can be recognized morphologically, I have opted to treat E. novomexicanus and E. pusillus as heterospecific. The holotypes (both males) of E. nebulosus and E. novomexicanus are similarly covered in dense tomentum and closely resemble one another, and it should be noted that sequenced specimens resembling the holotypes of both species but from nearer the type locality of E. novomexicanus were assigned a BIN that is not shared with E. nebulosus but is instead shared with E. pusillus .

Material studied.

Type material. Primary: USA: New Mexico: Santa Fe, 02.viii.1912, T.D. Cockerell (holotype ♂ [USNM, catalog number: 534049]).

DNA barcoded material with BIN-compliant sequences.

Available. BOLD:AAX7180. Specimens examined and sequenced.-USA: Utah: 4.17 mi SE Wig Mountain (40.2876°N; 113.0390°W) (Toole County), 26.ix.2005, T.L. Griswold (1♀, BBSL); Beef Basin Rd (38.0846°N; 109.5765°W) (N Cottonwood Creek, San Juan County), 03.x.2014, M.C. Orr (1♀, BBSL).

Non-barcoded material examined.

USA: Arizona: Near Hyde Park (Coconino County), 28.ix.1964, Timberlake (1♂, USNM); California: 8 mi W Coalinga (Fresno County), 28.ix.1957, R.R. Snelling (1♂, LACM); Los Angeles County, ix.????, Coquillett (1♀, USNM); Sugar Loaf Mountain (Modoc County), 12.ix.1969, E.E. Grissell and R.F. Denno (1♀, 1♂, UCBME); Victorville, 28.ix.1938, Timberlake (1♂, USNM); Colorado: Boulder (Boulder County), 28.viii.1976, U.N. Lanham (1♂, CUM); Great Sand Dunes National Monument (Alamosa County), 22.ix.1979, F.M. Brown (1♀, CUM); Great Sand Dunes National Monument (37.6629°N; 105.6212°W) (Alamosa County), 24.viii.2000, A.L. Hicks and V. Scott (1♀, 5♂, CUM); White Rocks (Boulder County), 24.vii.1934, C.H. Hicks (1♀, CUM); Idaho: Homedale, 16.viii.1974, R.M. Bohart (1♀, 1♂, UCBME); Montana: Ashland (Rosebud County), 11.viii.1970, D.R. Miller (1♀, USNM); Nebraska: Smiley Canyon (42.7964°N; 103.4045°W) (Fort Robinson State Park, Sioux County), 05.ix.1999, A.L. Hicks and V. Scott (1♀, CUM); Nevada: The Needle Rocks (N end Pyramid Lake, Washoe County), 15.ix.1983, J. Doyen (1♂, EMEC); New Mexico: Laguna, 07.viii.1966, D.R. Miller (1♀, 1♂, UCBME); Near Tecolote, 05.ix.??30 (1♀, USNM); White Sands National Monument (near Alamogordo), 01.ix.1940, H.G. Rodeck (1♂, CUM); North Dakota: 1 mi SE McLeod (Ransom County), 26.viii.1972, J.R. Powers (1♀, EMEC); Oregon: Deep Creek (1 mi E Adel, Lake County), 13.ix.1969, R.F. Denno and E.E. Grissell (2♂, UCBME); Utah: 0.5 mi S Springdell (Uinta National Forest), 22.viii.1963, C.W. O’Brien (1♂, AMNH); 1 mi N Kitchen Corral Spr 12S (Kane County), 10.ix.2002, L. Topham (1♀, BBSL); 13.2 mi N Blanding (San Juan County), 24.viii.??67, J.C. Hall (1♂, USNM); 16 mi W Tropic (37.3913°N; 112.2575°W) (Garfield County), 28.vii.2008, T.L. Griswold (1♀, BBSL); Beryl (Iron County), 27.ix.1953, M. Cazier (1♀, AMNH).