Epeolus banksi (Cockerell, 1907)

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 : 31-35

9. Epeolus banksi (Cockerell, 1907) Figs 20, 21, 96F

Triepeolus banksi Cockerell, 1907a. Entomologist 40: 135 (♂).

Epeolus banksi Mitchell, 1962. N. C. Agric. Exp. Stn. Tech. Bull. 152: 442.

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. banksi apart from all other North American Epeolus except E. minimus and E. olympiellus : in females, F2 is at least 1.2 × as long as wide; the mesoscutum has distinct paramedian bands; the axilla is small to intermediate in size, not extending much beyond the midlength of the mesoscutellum (extending to <2/3 its length) but the free portion is more than 1/4 as long as the entire medial length of the axilla, and the axilla and mesoscutellum are black; the mesopleuron is closely (most i<1d) and evenly punctate; T1 has a quadrangular discal patch, in dorsal view the longitudinal band is at least half as wide as the breadth of the apical fascia; and the T2 fascia has anterolateral extensions of tomentum. Whereas in E. minimus and E. olympiellus the mesoscutum and metasomal terga have bands of off-white to pale yellow short appressed setae, in E. banksi the mesoscutum and metasomal terga have bands of gray short appressed setae. In E. banksi , the integument is entirely dark brown or black. In E. olympiellus , at least the pronotal lobe is ferruginous. In E. minimus from California, the integument is often entirely dark brown or black, but throughout most of its range E. minimus exhibits reddish-orange coloration on the labrum, antenna, pronotal lobe, and/or legs, except foreleg, from trochanters to tarsi. Both sexes of E. banksi are larger (~10 mm in length) on average than E. minimus or E. olympiellus (7-8 mm in length).

Redescription.

MALE: Length 9.4 mm; head length 2.3 mm; head width 3.3 mm; fore wing length 7.5 mm.

Integument coloration. Mostly black; notable exceptions as follows: at least partially ferruginous on mandible, antenna, tegula, and legs. Mandible black except apex reddish brown; preapical tooth same color as mandibular apex (difficult to see in holotype; described from non-type specimens). Flagellum, except right F1 and F2, missing in holotype, but brown and (except F1) slightly lighter than conspicuously dark brown scape and pedicel, primarily due to extensive pilosity on flagellum, in non-type specimens. Wing membrane subhyaline, apically dusky. Legs, except reddish-orange tarsi, with brown or black more extensive than reddish orange.

Pubescence. Face with tomentum densest on clypeus and around antennal socket, sparser on upper paraocular area and vertexal area. Dorsum of mesosoma and metasoma with bands of off-white to pale gray short appressed setae. Mesoscutum with paramedian band. Mesopleuron densely hairy, except for two sparsely hairy circular patches (one behind pronotal lobe, a larger one occupying much of ventrolateral half of mesopleuron). Metanotum with tomentum uninterrupted, uniformly off white. T1 with median quadrangular black discal patch enclosed by pale tomentum, except for medial separation at apex. T2-T6 with fasciae interrupted medially, those of T2-T4 narrowed before becoming somewhat broader laterally, T2 with fascia with anterolateral extensions of sparser 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 matte spot lateral to lateral ocellus. Mesoscutum, mesoscutellum, and axilla coarsely and densely rugose-punctate. Tegula very densely punctate mesally (i<1d), less so laterally (i=1-2d). Mesopleuron with ventrolateral half densely punctate (i<1d); mesopleuron with punctures more or less equally dense throughout. Metasomal terga with punctures very fine, dense (i≈1d), evenly distributed on disc.

Structure. Labral apex with pair of small denticles, each preceded by longitudinal carina. Frontal keel not strongly raised. Scape with greatest length 1.6 × greatest width. F2 noticeably longer than wide (L/W ratio = 1.2). Preoccipital ridge not joining hypostomal carina, from which it is separated by about 1.5-2 MOD at its terminal. Mesoscutellum moderately bigibbous. Axilla intermediate in size, its lateral margin (L) nearly half as long as mesoscutellar width (W) (L/W ratio = 0.4-0.5) and tip not extending much beyond midlength of mesoscutellum (extending to <2/3 its length); axilla with tip clearly visible, but unattached to mesoscutellum for less than 2/5 the medial length of axilla; axilla with lateral margin relatively straight and without carina. 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 even longer than wide (L/W ratio = 1.4); T5 with two patches of pale tomentum bordering and separate from pseudopygidial area present only in female; T5 with pseudopygidial area lunate, its apex more than twice as wide as medial length, indicated by silvery setae on flat 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 ~2/5 MOD); pygidial plate apically truncate, with small, denser punctures.

Distribution.

Maryland to North Carolina (Fig. 21).

Ecology.

HOST RECORDS: The host species of E. banksi is/are presently unknown.

FLORAL RECORDS: Mitchell (1962) indicated a floral association with Fragaria L. ( Rosaceae ). Labels of examined voucher specimens further indicate associations with Solidago L. ( Compositae ) and Symphyotrichum ericoides (L.) G.L. Nesom ( Compositae ).

Discussion.

Most of the specimens of this species that were examined were collected in the Washington metropolitan area. While Mitchell (1962) indicated Epeolus banksi as being quite prevalent across the Eastern United States, reportedly ranging from Minnesota to New Jersey and North Carolina, it seems that the name has been commonly misapplied to specimens of E. minimus (as in MacKay and Knerer (1979) for example, and probably by Mitchell (1962) as well). Epeolus banksi is much larger than E. minimus , and has completely black integument, but unlike similarly dark specimens of E. minimus from California, E. banksi has gray as opposed to pale yellow bands of tomentum on the mesosoma and metasoma. Unfortunately, no recently collected material was available for barcode sequencing, and the specimens seen are all from the early 1900s. The absence of this species from recent collections has not gone unnoticed (e.g in Colla et al. 2012 it is listed among the bee species not collected since 1990). Increased urbanization in and around Washington D.C. may have resulted in the extirpation of this species there, and perhaps it has even disappeared entirely throughout its earlier range. Hence, extensive efforts should be made to rediscover this species, by sampling its apparent historical range between North Carolina and Maryland, to assess its conservation status. The flight season of E. banksi appears to be late summer/early autumn.

Material studied.

Type material. Primary: USA: Virginia: Falls Church, 26.viii.????, N. Banks (holotype ♂ [USNM, catalog number: 534038]).

Secondary: USA: Virginia: Falls Church, 07.ix.????, N. Banks (paratype ♂, CAS).

DNA barcoded material with BIN-compliant sequences.

Unavailable.

Non-barcoded material examined.

USA: Maryland: Glen Echo (Montgomery County), 30.viii.1923, J.R. Malloch (1♂, USNM); North Carolina: Valley of Black Mountains, 30.ix.1906, W. Beutenmuller (1♂, AMNH); Virginia: Chain Bridge, 10.ix.1922, J.R. Malloch (1♂, USNM); Falls Church, G.G. Rohwer (1♂, USNM); Glencarlyn?, 20.ix.??30 (1♂, USNM); Washington, D.C. (2♀, BBSL); Rock Creek Park, 28.viii.1919, J.C. Crawford (1♂, AMNH).