Epeolus inornatus, Onuferko, Thomas M., 2018

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 : 98-101

28. Epeolus inornatus sp. n. Figs 59, 60, 92G, 93C, 96D, 100B

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. inornatus apart from all other North American Epeolus except E. erigeronis and E. ilicis : the mandible is simple; the axilla does not attain the midlength of the mesoscutellum but the free portion is distinctly hooked, with the tip unattached to the mesoscutellum for more than 1/3 of the entire medial length of the axilla; the pronotal collar and metasomal terga are black; the metasomal terga have rather fine punctures; and the pseudopygidial area of the female is distinctly campanulate with the apex <2 × the medial length and not in contact with two large patches of pale tomentum (one on each side) throughout its length (in contact only at apex, diverging basally). Epeolus inornatus is most similar to E. ilicis , and in both species the mesopleuron has punctures that are similar in size and shiny interspaces that are commonly equal to the puncture diameters. By contrast, in E. erigeronis the punctures are more variable in size, with many smaller punctures among large ones, and most interspaces are narrower such that the surface appears to be very coarsely and densely rugose-punctate. Whereas in E. ilicis the pronotal lobe and legs are more extensively reddish orange than brown or black (at least the anterior surface of the metatibia and metatarsus are the same reddish orange color), the dorsum of the mesosoma and metasoma have gray but also usually some pale yellow short appressed setae, and S4 and S5 of the male have long curved coppery to silvery subapical hairs, in E. inornatus the legs (and sometimes the pronotal lobe and tegula) are usually darker, at least from the metacoxa to metatibia, the dorsum of the mesosoma and metasoma have gray short appressed setae, and S4 and S5 of the male have short straight subapical hairs. Epeolus inornatus is also similar to E. gibbsi , but in E. gibbsi the mandible has a blunt, obtuse preapical tooth; in males S4 and S5 have long curved coppery to silvery subapical hairs, as in E. ilicis and all other Nearctic Epeolus ; in females F2 is less than 1.2 × as long as wide (it is more than 1.2 × as long as wide in female E. inornatus ); and the pseudopygidial area of the female is in contact with two large patches of pale tomentum (one on each side [the two are parallel to each other]) throughout its length.

Description.

FEMALE: Length 8.2 mm; head length 1.9 mm; head width 2.6 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, and legs. Mandible with apex darker than all but extreme base. Antenna dark brown except F1 reddish brown in part. Pronotal lobe dark brown to black. 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. 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 gray short appressed setae. Mesoscutum with paramedian band. Mesopleuron with upper half hairy, ventrolateral half nearly bare. Metanotum with tomentum uninterrupted except for median bare patch in posterior half, uniformly off white. T1 with median quadrangular black discal patch enclosed by pale tomentum, except for medial separation at apex. T2 with fascia interrupted medially and with faint anterolateral extensions of sparser tomentum. T3 and T4 with fasciae complete. T5 with two large patches of pale tomentum lateral to and contacting pseudopygidial area at apex, diverging from pseudopygidial area basally. T5 with pseudopygidial area campanulate, 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. 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 mesally (i<1d), less so laterally (i=1-2d). Mesopleuron with ventrolateral half densely punctate (i≤1d), the interspaces shining; mesopleuron with punctures similar in size and more or less equally dense throughout. Metasomal terga with punctures very fine, dense (i=1-2d), evenly distributed on disc; the interspaces shining somewhat.

Structure. Mandible without preapical tooth. Labrum with pair of small subapical denticles not preceded by carinae. Frontal keel not strongly raised. Scape with greatest length 1.9 × greatest width. F2 noticeably longer than wide (L/W ratio = 1.4). Preoccipital ridge not joining hypostomal carina, from which it is separated by no less than 1 MOD at its terminal. 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 conspicuously diverging from side of mesoscutellum, distinctly hooked, and axilla with free portion 2/5 its medial length; axilla with lateral margin relatively straight and carinate. 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, not noticeably longer than wide (L/W ratio = 1.1); pygidial plate apically rounded, with large deep punctures closely clustered.

Etymology.

The name is in reference to the grayish pubescence and largely monochromatic dark brown or black integument of this species. From the Latin, “inornatus” (unadorned).

Distribution.

Mid-Atlantic states to Texas (Fig. 60).

Ecology.

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

FLORAL RECORDS: Labels of examined voucher specimens indicate floral associations with Quercus laevis Walter ( Fagaceae ) and Vaccinium arboreum Marshall.

Discussion.

The specimens from Texas, USA that Brumley (1965) identified as E. ilicis are probably E. inornatus . Although BIN-compliant sequences are presently not available for E. inornatus , a single 421 bp sequence is available for a female specimen (the holotype) from East Texas, which does not cluster with the single sequence (422 bp in length) available for what is herein considered to be the true E. ilicis (a male specimen from Florida, USA) based on its greater resemblance to the holotype of that species (Suppl. material 2). Instead, the sequence from the Florida specimen clusters with sequences of E. zonatus , which is a visibly different bee, and all were assigned the same BIN. Whereas male E. inornatus are unique among Epeolus in having very short straight subapical hairs on S4 and S5 instead of the usual long curved coppery to silvery subapical hairs, females are practically indistinguishable from E. ilicis in terms of surface sculpture and structure. Although consistent, the features (differences in integument coloration and pubescence) that in combination may be used to distinguish female E. inornatus from E. ilicis are subtle. Based on known records, adults of E. inornatus appear to be most active in spring, the same time of year when adults of E. ilicis and E. zonatus are active.

Material studied.

Type material. Primary: USA: Texas: Lick Creek Park (College Station, Brazos County), 05-09.iv.2000, M. Buck (holotype ♀ [DEBU, catalog number: 00106728]).

Secondary: USA: Arkansas: Magazine Mountain (Logan County), 23.v.1991, J. Powell (paratype ♀, EMEC); Florida: Liberty County, 24.iv.1961, H.V. Weems, Jr. (paratype ♂, BBSL); Torreya State Park (Liberty County), 12.v.1968, H.V. Weems, Jr. (paratype ♂, FSCA); Georgia: 2 mi SE Blue Ridge (Fannin County), 29.vi.1982, J.B. Whitfield (paratype ♂, EMEC); Rabun Bald (Rabun County), 14.vii.1957, J.G. Chillcott (paratype ♀, CNC); Satolah (Rabun County), 01.vii.1957, J.R. Vockeroth (paratype ♀, CNC), 04.vii.1957, W.R.M. Mason (paratype ♂, CNC); Massachusetts: Amherst, spring 1929, L.A. Carruth (paratype ♂, USNM); North Carolina: Chestnut Bald (Pisgah National Forest, Haywood County), 02.viii.1957, J.G. Chillcott (paratype ♀, CNC); Highlands, 27.vi.1957, W.R.M. Mason (paratype ♀, CNC), 27.vi.1957, J.R. Vockeroth (paratypes 3♂, CNC), 29.vi.1957, J.R. Vockeroth (paratype ♀, CNC), 25.vi.1957, W.R.M. Mason (paratype ♂, CNC); Horse Cove (Highlands), 27.vi.1957, J.R. Vockeroth (paratype ♂, CNC); Wayah Bald (Macon County), 06.vii.1957, W.R.M. Mason (paratype ♀, CNC); Whiteside Mountain (Highlands), 29.vi.1957, W.R.M. Mason (paratype ♀, CNC); South Carolina: Mountain Rest, 14.vi.1957, W.R.M. Mason (paratype ♂, CNC); Texas: 2.5 mi S Delhi (29.7730°N; 97.4020°W) (Caldwell County), 19.iv.2007, J.L. Neff and A. Hook (paratype ♀, CTMI); 8 km SE Elkhart (Anderson County), 27.iv.1985, C.D. Michener (paratype ♂, KUNHM); Brackenridge Field Laboratory (Austin, Travis County), 13.v.1988, A. Hook (paratype ♂, CTMI); Lick Creek Park (College Station, Brazos County), 05-09.iv.2000, M. Buck (allotype ♂ [DEBU, catalog number: 00106727]); Stengl Lost Pines Biological Research Station (30.0800°N; 97.1830°W) (Bastrop County), 13.iv.2006, J.L. Neff (paratype ♀, CTMI).

DNA barcoded material with BIN-compliant sequences.

Unavailable.

Non-barcoded material examined.

USA: North Carolina: Whiteside Mountain (Macon County), 11.vii.1937, T.B. Mitchell ( E. ilicis paratype ♂, NCSU).