Epeolus australis Mitchell, 1962

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 : 24-25

6. Epeolus australis Mitchell, 1962 Figs 2A, 14, 15, 97I, 103A

Epeolus australis Mitchell, 1962. N. C. Agric. Exp. Stn. Tech. Bull. 152: 441 (♀).

Diagnosis.

The following morphological features in combination can be used to tell E. australis apart from all other North American Epeolus : the frontal carina is strongly convex, such that the supraclypeal area is distinctly protuberant in lateral view; T1-T4 have complete fasciae; and the T2 fascia has a pair of anterolateral extensions of tomentum that are strongly convergent basally. In E. chamaesarachae and E. diadematus and commonly in E. bifasciatus the frontal carina is also strongly convex, but in the first two species the vertexal area has two pairs of shiny (usually impunctate) protrusions and in E. bifasciatus the frontal area bears a pair of granulose protrusions whereas in E. australis the frontal and vertexal areas lack protrusions. Epeolus australis most closely resembles E. brumleyi , but in E. brumleyi the frontal carina is only weakly convex and the pygidial plate of the male is wider (the medial length ≈ the basal width) than in E. australis (the medial length is ~1.5 × the basal width).

Redescription.

FEMALE: Length 7.5 mm; head length 2.0 mm; head width 2.8 mm; fore wing length 5.7 mm.

Integument coloration. Mostly black; notable exceptions as follows: partially to entirely ferruginous on mandible, antenna, pronotal lobe, tegula, axilla, mesoscutellum, legs, pygidial plate, and metasomal sterna. Mandible with apex darker than rest of mandible; preapical tooth slightly lighter than mandibular apex. Both antennae missing in holotype, but brown and orange in part in paratype. Pronotal lobe and tegula pale ferruginous to amber. Wing membrane subhyaline, apically dusky. Legs more extensively reddish orange than brown or black.

Pubescence. Face with tomentum densest around antennal socket, slightly sparser on clypeus, upper paraocular and frontal areas, and vertexal area. Dorsum of mesosoma and metasoma with bands of off-white to pale yellow short appressed setae. Mesoscutum with paramedian band. Mesopleuron with upper half densely hairy, except beneath base of fore wing (hypoepimeral area); ventrolateral half sparsely hairy. Metanotum with tomentum uninterrupted, uniformly off white. T1 with discal patch elliptical and very wide, the basal and apical fasciae only narrowly joined laterally. T1 with basal and apical fasciae and T2-T4 with apical fasciae complete, T2 with fascia with basomedially convergent anterolateral extensions of tomentum. T5 with two large patches of pale tomentum lateral to and separate from pseudopygidial area, enclosing pseudopygidial area in triangle, except for medial separation at base. T5 with pseudopygidial area lunate, its apex more than twice as wide as medial length, indicated by silvery setae on disc of apicomedial region elevated from rest of tergum. S5 with apical fimbria of coppery to silvery hairs extending beyond apex of sternum by ~1/3 MOD.

Surface sculpture. Punctures dense. Labrum with larger punctures than clypeus, but punctures of both equally dense (i≤1d). Impunctate spot lateral to lateral ocellus absent in holotype, but shiny spot present in some non-type specimens. Mesoscutum, mesoscutellum, and axilla coarsely and densely rugose-punctate. Tegula 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. Preapical tooth inconspicuous, blunt and obtuse. Labrum with pair of small subapical denticles (approximately at 1/4 length of labrum from apical margin) not preceded by carinae. Frontal keel strongly raised. Scape (missing in holotype) with greatest length 1.6 × greatest width in paratype. F2 (missing in holotype) not noticeably longer than wide (L/W ratio = 1.1) in paratype. Preoccipital ridge not joining hypostomal carina, from which it is separated by no less than 1 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 beyond midlength of mesoscutellum; axilla with tip 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 truncate.

MALE: Description as for female except for usual secondary sexual characters and as follows: F2 shorter, as long as wide (L/W ratio = 1.0); S4 and S5 with much longer coppery to silvery subapical hairs, which individually are often darker apically; pygidial plate unusually narrow ( Triepeolus -like) and apically rounded, with large deep punctures closely clustered.

Distribution.

Mid-Atlantic states to Texas and presumably Mexico, given the close proximity of some collection localities (e.g., Eagle Pass, Texas) to the Mexico–United States border (Fig. 15).

Ecology.

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

FLORAL RECORDS: Mitchell (1962) indicated floral associations with Ceanothus L. ( Rhamnaceae ), Rubus L. ( Rosaceae ), Senecio L. ( Compositae ), and Specularia (now Triodanis ? Raf. ex Greene) ( Campanulaceae ). Labels of examined voucher specimens further indicate associations with Chaetopappa asteroides (Nutt.) Nutt. ex DC. ( Compositae ), Hymenopappus artemisiifolius DC. ( Compositae ), and Sphaeralcea .

Discussion.

This southeastern species displays minor sexual dimorphism in the coloration of the mesoscutellum, which is bright ferruginous in females and dark ferruginous to black in males. Otherwise, there is very little morphological variation among examined specimens. Although BIN-compliant sequences are presently not available for E. australis , 422 bp sequences were obtained from two male specimens (one from New Jersey, USA and one from South Carolina, USA), and there is virtually no divergence (<1%) between the two. Moreover, these sequences do not cluster with any sequences from other Epeolus species in a NJ tree (Suppl. material 2). Based on known records, adults of E. australis are active in spring.

Material studied.

Type material. Primary: USA: North Carolina: Raleigh, 19.v.1950, T.B. Mitchell (holotype ♀, NCSU).

Secondary: USA: North Carolina: Raleigh, 09.v.1948, T.B. Mitchell (paratype ♀, NHMUK), 19.v.1950, T.B. Mitchell (paratype ♀, USNM).

DNA barcoded material with BIN-compliant sequences.

Unavailable.

Non-barcoded material examined.

USA: Florida: Alachua (Alachua County), 29.iv.1974, E.E. Grissell (2♀, UCBME); Georgia: Augusta (Richmond County), 18.v.1959, R.R. Snelling (1♀, LACM), 17.v.1959, R.R. Snelling (1♀, LACM), 03.v.1959, R.R. Snelling (1♂, LACM), 26.iv.1959, R.R. Snelling (1♂, LACM); Fort Gordon (Richmond County), 08.v.1958, R.R. Snelling (1♀, LACM); Maryland: Bowie (Prince George’s County), 08.vi.1968, R.R. Snelling (1♂, LACM); New Jersey: Forsythe (39.5296°N; 74.3421°W) (Atlantic and Ocean counties), 01-30.vi.2008, M. Springer (1♀, BIML); South Carolina: Carolina Sandhills National Wildlife Refuge (34.6043°N; 80.2469°W) (Chesterfield County), 18-19.v.2006, S.W. Droege (1♂, BIML); Texas: 10.7 mi S Dryden (Terrell County), 21.iv.1973, R.R. Snelling (1♂, LACM); 12 mi S Seguin (29.4060°N; 97.8550°W) (TX-123, Guadalupe County), 03.v.2014, J.L. Neff (1♀, CTMI); 8-25 km N Castroville (Medina County), 12.v.1988, B.N. Danforth (1♀, KUNHM); Camp Swift (30.2910°N; 97.3060°W) (Bastrop County), 24.iv.2003, J.L. Neff (1♀, CTMI); Eagle Pass (Maverick County), 28.iii.1946, C.D. Michener (2♂, AMNH); Hwy 83 (14 mi S Jct. Texas State Hwy 44, Webb County), 21.iv.1973, R.R. Snelling (1♀, LACM); Nacogdoches (Nacogdoches County), 14.iv.1960 (1♀, KUNHM); Stengl Lost Pines Research Station (30.0800°N; 97.1830°W) (Bastrop County), 02.iv.2006, J.L. Neff (1♀, CTMI).