Epeolus asperatus Cockerell, 1909

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 : 15-20

4. Epeolus asperatus Cockerell, 1909 Figs 2D, 10, 11, 92L

Epeolus asperatus Cockerell, 1909. Ann. Mag. Nat. Hist. 5: 25 (♀).

Epeolus melectimimus Cockerell & Sandhouse, 1924. Proc. Calif. Acad. Sci. (4) 13: 317 (♂), syn. n.

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. asperatus apart from all other North American Epeolus except E. americanus and E. barberiellus : in females, F2 is not more than 1.1 × as long as wide; the mesoscutum has distinct paramedian bands; the axilla is small to intermediate in size, not extending beyond the midlength of the mesoscutellum and the free portion is less than 1/4 as long as the entire medial length of the axilla, and like the mesoscutellum 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 as wide as the breadth of the apical fascia; and the T1 and T2 apical fasciae are interrupted or at least greatly narrowed medially. Whereas in E. barberiellus the legs, at least from the tibiae to tarsi (sometimes the trochanters and femora as well), are reddish orange and the metasomal terga are fasciate, in E. asperatus the legs are brown or black and the T3 and T4 fasciae are broken or at least greatly narrowed laterally, as well as medially into separated or narrowly connected oval patches. Epeolus asperatus is most similar to E. americanus , but in E. americanus the mesopleuron has sparser punctures ventrolaterally (i≤1d) than that of E. asperatus , with the interspaces shining, and the T3 and T4 fasciae are complete or broken medially and/or laterally, but rarely into separated oval patches.

Redescription.

FEMALE: Length 7.8 mm; head length 2.0 mm; head width 2.8 mm; fore wing length 5.4 mm.

Integument coloration. Mostly black; notable exceptions as follows: at least partially ferruginous on mandible, labrum, antenna, pronotal lobe, tegula, and legs. Mandible with apex darker than rest of mandible; preapical tooth lighter than mandibular apex (difficult to see in the E. asperatus holotype; described from non-type specimens). Antenna brown except F1 and F2 orange in part. Flagellum slightly lighter than conspicuously dark brown scape and pedicel, primarily due to extensive pilosity on flagellum. Pronotal lobe and tegula pale ferruginous to amber. Wing membrane subhyaline, apically dusky. Legs with brown or black more extensive than reddish orange.

Pubescence. Face with tomentum densest around antennal socket. Dorsum of mesosoma and metasoma with bands of off-white to pale yellow short appressed setae. Mesoscutum with paramedian band. Mesopleuron with upper half hairy, ventrolateral half nearly bare. Metanotum with tomentum rubbed off medially in the E. asperatus holotype, but somewhat sparser medially and uniformly off white in non-type specimens. T1 with median quadrangular black discal patch enclosed by pale tomentum, except for medial separation at apex, and narrow, such that longitudinal band nearly half as wide as width of discal patch in dorsal view. T2-T4 with fasciae interrupted medially and with anterolateral extensions of sparser tomentum. T3 and T4 with fasciae also interrupted laterally, appearing as pair of oval patches between medial and lateral interruptions. T5 with two patches of pale tomentum lateral to and separate from pseudopygidial area (difficult to see in the E. asperatus holotype because T5 mostly retracted; described from non-type specimens). T5 with pseudopygidial area lunate, its apex more than twice as wide as medial length, indicated by silvery setae on impressed disc of apicomedial region elevated from rest of tergum. S5 with apical fimbria of coppery to silvery hairs not extending beyond apex of sternum by more than 1/4 MOD.

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 very densely punctate (i<1d). 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. Preapical tooth with blunt tip. Labrum with pair of small subapical denticles, each preceded by small discrete longitudinal ridge. Frontal keel not strongly raised. Scape with greatest length 1.9 × greatest width. F2 as long as wide (L/W ratio = 1.0). Preoccipital ridge not joining hypostomal carina, from which it is separated by about 1.5-2 MOD at its terminal (difficult to see in the E. asperatus holotype; described from non-type specimens). Mesoscutellum moderately bigibbous. Axilla small to intermediate in size, its lateral margin (L) less than half as long as mesoscutellar width (W) (L/W ratio = 0.4) and tip not extending beyond midlength of mesoscutellum; axilla with tip visible, but unattached to mesoscutellum for less than 1/3 the medial length of axilla; axilla with lateral margin relatively straight and without carina. Fore wing with second submarginal crossvein incomplete in the E. asperatus holotype; with submarginal cells two or three and closed or second submarginal crossvein incomplete in non-type specimens. Pygidial plate apically truncate.

MALE: Description as for female except for usual secondary sexual characters and as follows: F2 shorter, nearly as long as wide (L/W ratio = 0.8); S4 and S5 with much longer coppery to silvery subapical hairs; pygidial plate V-shaped but apically rounded, with large deep, well-separated punctures, with the interspaces shining.

Distribution.

Central and southern California (Fig. 11).

Ecology.

HOST RECORDS: Nine representatives of this species were collected at the Robert J. Bernard Biological Field Station in Claremont, California, USA in the spring of 2016 (see Material studied), and the only Colletes collected or observed was a single female of a predominantly black species with pale pubescence limited to the mesosoma. The collected female of the possible host species was barcoded, and using Stephen’s (1954) key identified as C. californicus Provancher. However, its sequence clusters with sequences of specimens collected in New Mexico (also in the spring of 2016) and identified as C. sphaeralceae Timberlake (with entirely/predominantly pale pubescence) through the use of Stephen’s (1954) key, dissection of the male terminalia, and collection from red Sphaeralcea A. St.-Hil. ( Malvaceae ) flowers, and all were assigned the same BIN (BOLD:ABZ4529). Another predominantly black female specimen from the San Diego National Wildlife Refuge Otay-Sweetwater Unit in California was barcoded (its image and 601 bp sequence are available on the Barcode of Life Data Systems website [http://www.barcodinglife.org/]), and was assigned the same BIN as the female from Claremont and specimens from New Mexico.

FLORAL RECORDS: Labels of examined voucher specimens indicate floral associations with Lasthenia Cass. ( Compositae ) and Plagiobothrys .

Discussion.

Brumley (1965) synonymized E. asperatus and E. melectimimus under E. americanus , but current evidence suggests that the holotypes of E. asperatus and E. melectimimus belong to a cryptic species within the "americanus group", distinct from E. americanus and E. barberiellus . In addition to the subtle diagnostic morphological features that separate E. asperatus from E. americanus and E. barberiellus , the status of E. asperatus as a separate species is supported by a separate BIN and large barcode sequence divergence (4.4%) from its nearest neighbor, E. barberiellus .

Epeolus melectimimus , with three submarginal cells, was described by Cockerell and Sandhouse (1924), who claimed that the species resembles a small Pseudomelecta Radoszkowski (a subgenus of Melecta Latreille in Michener 2007), from which it can be readily distinguished based on differences in the marginal cell. In the E. asperatus holotype, the second submarginal crossvein on each side is incomplete and inconspicuous. A series of E. asperatus was collected from the Robert J. Bernard Biological Field Station in Claremont, California, USA, which is in the same county as the type locality (Los Angeles). In some specimens, the fore wing has three submarginal cells whereas in others, the second submarginal crossvein is incomplete or lacking entirely. In some specimens, one fore wing has three submarginal cells and the other has an incomplete second submarginal crossvein. The male holotype of E. melectimimus was examined, and excluding sex-specific features the specimen with few exceptions agrees with the present redescription based on the female holotype of E. asperatus . Along with the abovementioned differences in wing venation, the pronotal lobe and tegula are darker in the holotype of E. melectimimus than in that of E. asperatus , but these differences fall within the range of observed intraspecific morphological variation among sequenced specimens. Although both E. americanus and E. asperatus are present in California, E. americanus appears to be absent from the southern part of the state.

Material studied.

Type material. Primary: USA: California: Huntington Lake (Fresno County), 07.vii.1919, E.P. Van Duzee ( E. melectimimus holotype ♂ [CAS, catalog number: 01612]); Los Angeles (Los Angeles County), 24.iv.1909, F. Grinnell, Jr. ( E. asperatus holotype ♀ [USNM, catalog number: 534036]).

DNA barcoded material with BIN-compliant sequences.

Available. BOLD:ACZ2142. Specimens examined and sequenced. USA: California: Robert J. Bernard Biological Field Station (Claremont, Los Angeles County), 18.iv.2002, M.G. Rightmyer (1♀, KUNHM); Robert J. Bernard Biological Field Station (34.1083°N; 117.7100°W) (Claremont, Los Angeles County), 13.iv.2016, T.M. Onuferko (2♂, PCYU).

Non-barcoded material examined.

USA: California: 2 mi S Hilmar (Merced County), 19.iv.1960, R.R. Snelling (1♀, AMNH); 2 mi S Pearblossom (Los Angeles County), 01-02.v.1977, R.R. Snelling (1♂, LACM); Arroyo Seco Campground (Monterey County), 01.v.1960, F.D. Parker (1♂, UCBME), 19.v.1964, R.M. Bohart (1♂, UCBME), 11.v.1971, R.M. Bohart (3♀, 2♂, UCBME); Claremont (Los Angeles County), Baker (1♂, USNM), Metz (1♀, AMNH); Devore (San Bernardino County), 21.vi.1974, J.C. and E.M. Hall (1♂, UCR); East Fork Kaweah River (Tulare County), 02.vii.1976, T.L. Griswold (1♀, BBSL); Millard Canyon (Riverside County), 07.iv.1974, J.C. and E.M. Hall (1♀, UCR); Moreno Valley (base of Box Springs Mountains, Riverside County), 26.iv.1992, R.K. Velten (1♀, UCR); Robert J. Bernard Biological Field Station (34.1083°N; 117.7100°W) (Claremont, Los Angeles County), 13.iv.2016, T.M. Onuferko (2♀, 1♂, PCYU), 14.iv.2016, T.M. Onuferko (1♀, PCYU), 26.iv.2016, T.M. Onuferko (3♂, PCYU); W L Jepson Prairie Preserve (TNC) (13 mi S Dixon, Solano County), 20.v.1983, J.D. Barbour (1♂, UCBME).