Triepeolus simplex Robertson, 1903

Onuferko, Thomas M. & Rightmyer, Molly G., 2024, A revision of the simplex species group of the cleptoparasitic bee genus Triepeolus Robertson, 1901 (Hymenoptera: Apidae), European Journal of Taxonomy 950 (1), pp. 1-106 : 91-96

Triepeolus simplex Robertson, 1903

Figs 10A , 12P , 18D, 31

Triepeolus simplex Robertson, 1903: 285 (♀, ♂).

Triepeolus simplex – Mitchell 1962: 483 (redescription). — Webb 1980: 110 (♀) (lectotype designation by W.E. LaBerge).

Proposed common name

Simple triepeolus.

Diagnosis

Unique to T. simplex within the simplex species group is the presence of only short, straight setae (as opposed to an apical/subapical fringe of dense, long (> 1 MOD), curved setae) on the male S5 ( Figs 10A , 31C ). Otherwise, the following morphological features in combination tell both sexes of T. simplex apart from all other species of Triepeolus : the clypeus does not have a glabrous midline (Supp. file 2: Fig. S25C ); the T1 discal patch is trapezoidal or almost semicircular ( Fig. 31B ); T2– T4 have apical transverse bands of pale tomentum that are clearly not as broad as the bands on T1 and do not have basomedially convergent anterolateral extensions ( Fig. 31A–C ); and the T2–T3 apical transverse bands are yellow and somewhat removed from the apical margins of the terga whereas the T4 apical transverse band is off-white and on or very little removed from the apical margin of the tergum ( Figs 10A , 31A–C ). Males of T. simplex are very similar in overall appearance to those of T. lunatus (Say, 1824) (outside of the simplex species group), but in males of T. lunatus both S4 and S5 each have an apical/subapical fringe of dense, long (> 1 MOD), curved setae and in both sexes the clypeus has a well-defined glabrous midline that extends most if not all of its length.

Etymology

The specific epithet is a Latin adjective meaning ‘simple,’ but it is not clear from the original description why Robertson (1903) chose this name.

Material examined

Primary type material

USA • ♀, lectotype; Illinois, Carlinville , Macoupin County; 14 Aug. 1896; C.A. Robertson leg.; INHS 62277 .

Secondary type material

USA • 1 ♂, lectoallotype; Illinois, Carlinville , Macoupin County; 7 Aug. 1897; C.A. Robertson leg.; INHS 62278 .

DNA barcoded material

Available. BIN: BOLD:AAW8070. Specimens examined and sequenced:

CANADA • 1 ♂; Ontario, Queen’s University Biological Station ; 3 Aug. 2005; Forney and Gravel leg.; BOLD sample ID: QUBS0291G11 ; PCYU .

USA – Michigan • 1 ♀; Flynn Township Nature Center , Sanilac County; 43.2670° N, 82.9480° W; 4 Aug. 2018; T.J. Wood leg.; BOLD sample ID: CMNTO_158 ; WRME JBWM0398680 . – North Carolina • 1 ♀; Nellie (near Cataloochee ), Great Smoky Mountains National Park , Haywood County; 35.6249° N, 83.1139° W; 6 Aug. 2006; J. Gibbs and C.S. Sheffield leg.; BOLD sample ID: CMNTO_038 ; PCYU PYU-319 . – Oklahoma • 1 ♀; Keystone Wildlife Management Area ( Arkansas River ), Osage County; 36.3066° N, 96.5221° W; 1 Jul. 2022; M.E. Powley leg.; BOLD sample ID: CMNTO_453 ; OKBS OKBS.POL.4927 . – Vermont • 1 ♀; Intervale Community Farm , Burlington; 44.4955° N, 73.2072° W; 3 Sep. 2019; S. Hardy leg.; BOLD sample ID: CMNTO_097 ; VCE 4244 .

Non-barcoded material

CANADA – Ontario • 1 ♀; near St-Albert ; 45.2528° N, 75.2030° W; 25 Jul.–1 Aug. 2019; S. Cardinal leg.; CNC 1595850 • 1 ♀; Sixteen Mile Creek (near Hwy 407), Oakville ; 19 Aug. 2004; M. Buck leg.; DEBU debu00240350 • 1 ♂; Centennial Park (Toronto); 43.6584° N, 79.5899° W; 28 Aug. 2019; S. MacKell leg.; PCYU .

USA – Arkansas • 2 ♀♀; Polk County; 21 Aug. 1928; A.M. James leg.; KUNHM M.G.R. Database Nos 4615 , 4616 . – Georgia • 1 ♂; Morrison ; USNM M.G.R. Database No. 6638 • 1 ♀; SW of Watkinsville , Oconee County; 22 Aug. 1981; C.K. Starr leg.; USNM M.G.R. Database No. 1344 . – Illinois • 1 ♀; Carlinville , Macoupin County; C.A. Robertson leg.; AMNH acc 38827/M.G.R. Database No. 3612 . – Indiana • 1 ♂; Conrad , Newton County; 8 Jul. 2001; R.P. Jean leg.; RJC #3059/M.G.R. Database No. 6678 . – Iowa • 1 ♀; Co. 3; 19 Aug. 1933; Barker leg.; USNM M.G.R. Database No. 5895 . – Kansas • 1 ♀; 5 km E of Lawrence , Douglas County; 3 Sep. 1984; R. Brooks and C. Michener leg.; KUNHM M.G.R. Database No. 4608 • 1 ♀; 5 mi W of Lawrence , Douglas County; 10 Sep. 1950; J.R. White leg.; KUNHM M.G.R. Database No. 4601 • 1 ♀; 7 km E of Lawrence , Douglas County; 15 Aug. 1990; R.L. Minckley leg.; KUNHM M.G.R. Database No. 4605 • 1 ♀; Allen County; R.H. Beamer leg.; KUNHM M.G.R. Database No. 4612 • 1 ♀; Baldwin ; USNM M.G.R. Database No. 6452 • 1 ♂; same data as for preceding; Jul.; Bridwell leg.; USNM M.G.R. Database No. 6639 • 1 ♂; same data as for preceding; Jul.; J.C. Bridwell leg.; USNM M.G.R. Database No. 6640 • 2 ♂♂; DeSoto ; 13 Aug. 1952; W.E. LaBerge leg.; KUNHM M.G.R. Database Nos 4580 , 4588 • 1 ♀; Douglas County; F.H. Snow leg.; KUNHM M.G.R. Database No. 3939 • 1 ♀; same data as for preceding; 30 Jul. 1949; C.D. Michener leg.; KUNHM M.G.R. Database No. 4600 • 2 ♂♂; same data as for preceding; 30 Jul. 1951; C.D. Michener leg.; KUNHM M.G.R. Database Nos 4579 , 4582 • 1 ♂; same data as for preceding; 2 Aug. 1951; W.E. LaBerge leg.; KUNHM M.G.R. Database No. 4585 • 1 ♀; same data as for preceding; 16 Aug. 1951; W.E. LaBerge leg.; KUNHM M.G.R. Database No. 4604 • 1 ♀; same data as for preceding; 20 Aug. 1951; W.E. LaBerge leg.; KUNHM M.G.R. Database No. 4607 • 1 ♂; same data as for preceding; 18 Aug. 1955; C.W. Rettenmeyer leg.; KUNHM M.G.R. Database No. 4589 • 1 ♂; Lawrence , Douglas County; 23 Jul. 1949; Michener and Rozen leg.; AMNH M.G.R. Database No. 3611 • 1 ♀; same data as for preceding; 9 Aug. 1950; J.R. White leg.; KUNHM M.G.R. Database No. 4598 • 2 ♂♂; same data as for preceding; 9 Aug. 1950; J.R. White leg.; KUNHM M.G.R. Database Nos 4581 , 4583 • 2 ♂♂; same data as for preceding; 16 Aug. 1950; J.R. White leg.; KUNHM M.G.R. Database Nos 4584 , 4587 • 1 ♀; same data as for preceding; 18 Aug. 1950; J.R. White leg.; KUNHM M.G.R. Database No. 4603 • 1 ♂; same data as for preceding; 18 Aug. 1950; J.R. White leg.; KUNHM M.G.R. Database No. 4591 • 1 ♀; same data as for preceding; 18 Aug. 1951; C.D. Michener leg.; KUNHM M.G.R. Database No. 4599 • 3 ♂♂; same data as for preceding; 11 Jun. 1954; Daly leg.; USNM M.G.R. Database Nos 1345 to 1347 • 2 ♀♀; Lawrence vicinity; 30 Jul. 1977; S. Laroca leg.; KUNHM M.G.R. Database Nos 1322 , 4606 • 1 ♂; Ottawa; 20 Aug. 1950; C.D. Michener leg.; KUNHM M.G.R. Database No. 4590 • 1 ♂; Topeka ; 3 Aug. 1950; C.D. Michener and J.R. White leg.; KUNHM M.G.R. Database No. 4592 • 1 ♀; University of Kansas Natural History Reservation , Douglas County; 22 Jul. 1960; KUNHM M.G.R. Database No. 4602 . – Louisiana • 1 ♂; Logansport ; 13 Aug. 1905; La. Crop Pest Commission leg.; USNM M.G.R. Database No. 6643 . – Maryland • 1 ♀; Easton , Talbot County; 38.7683° N, 76.0754° W; 18 Jul. 2016; S.W. Droege leg.; BIML USGS-DRO 446669 • 3 ♂♂; Oxford , Talbot County; 38.6833° N, 76.1650° W; 11 Jul. 2018; S.W. Droege leg.; BIML USGS-DRO 536852 , USGS-DRO 536888 , USGS-DRO 536897. – Michigan • 1 ♀; Al Sabo Land Preserve ( Kalamazoo ); 42.2140° N, 85.6740° W; 29 Jul. 2017; T.J. Wood leg.; WRME JBWM0398679 . – Minnesota • 1 ♀; Dumfries , Wabasha County; 13 Aug. 1960; J.R. Powers leg.; LACM M.G.R. Database No. 3613 . – Mississippi • 1 ♂; USNM M.G.R. Database No. 6642 • 1 ♀; same data as for preceding; W.H. Ashmead leg.; USNM M.G.R. Database No. 1343 • 1 ♀; 7.3 km NE of Starkville , Oktibbeha County; 33.5100° N, 88.7369° W; 19 Jun. 2001; R. Brooks and T. Peterson leg.; KUNHM MISS1B01 002 /M.G.R. Database No. 4614 • 1 ♂; same data as for preceding; 19 Jun. 2001; R. Brooks and T. Peterson leg.; KUNHM MISS1B01 002 /M.G.R. Database No. 4597 . – Missouri • 1 ♂; 12 mi E of Lebanon ; 5 Aug. 1951; C.D. Michener leg.; KUNHM M.G.R. Database No. 4586 • 1 ♂; Atherton ; Jul. 1954; W.M. Mann leg.; USNM M.G.R. Database No. 1349 • 1 ♂; same data as for preceding; Aug. 1954; W.M. Mann leg.; USNM M.G.R. Database No. 1348 • 1 ♀; Columbia ; 5 Sep. 1967; F.D. Parker leg.; USNM M.G.R. Database No. 1342 • 1 ♀; Saline County (31 mi W of Boonville ); 2 Jul. 1999; L. Packer leg.; PCYU • 1 ♂; St. Louis ; 12 Aug. 1938; USNM M.G.R. Database No. 6641 . – Nebraska • 1 ♀; West Point ; 28 Jul. 1903; J.C. Crawford leg.; USNM M.G.R. Database No. 5893 • 1 ♀; same data as for preceding; 16 Aug. 1903; J.C. Crawford leg.; USNM Crawford no. 2268/M.G.R. Database No. 5894 . – North Carolina • 1 ♀; North Carolina ; USNM M.G.R. Database No. 1339 • 2 ♀♀; Edgecombe County; 28 Aug. 1996; W.A. Mangum leg.; KUNHM M.G.R. Database Nos 1340 , 1341 • 1 ♂; same data as for preceding; 29 Aug. 1996; W.A. Mangum leg.; KUNHM M.G.R. Database No. 4596 • 1 ♀; Tuckasegee ; 31 Aug. 1957; L.A. Kelton leg.; CNC. – Oklahoma • 1 ♂; Ardmore ; 1 Jun. 1909; F.C. Bishopp leg.; USNM M.G.R. Database No. 5590 • 1 ♀; Keystone Wildlife Management Area ( Arkansas River ), Osage County; 36.3066° N, 96.5221° W; 1 Jul. 2022; M.E. Powley leg.; OKBS OKBS.POL.4924 • 1 ♀; Lake Texoma (2 mi E of Willis ); Jun. 1965; R.M. Bohart leg.; UCBME M.G.R. Database No. 11682 • 1 ♂; Sequoyah National Wildlife Refuge , Sequoyah County; 35.4448° N, 95.0120° W; 5 Jul. 2022; M.E. Powley leg.; OKBS OKBS.POL.4958 • 1 ♀; Sequoyah National Wildlife Refuge , Sequoyah County; 35.4500° N, 95.0110° W; 26 Jun. 2023; S. O’Dell leg.; OKBS OKBS.POL.9870 . – South Carolina • 1 ♂; Swansea ; 8 Aug. 1911; F.K. Knab leg.; USNM M.G.R. Database No. 1410 . – Texas • 5 ♂♂; 1877; J. Tosquinet leg.; IRSNB M.G.R. Database Nos 762 to 766 • 2 ♀♀; 16 mi E of Goliad ; 7 May 1953; R.H. Beamer leg.; KUNHM M.G.R. Database Nos 4609 , 4611 • 1 ♂; same data as for preceding; 7 May 1953; R.H. Beamer leg.; KUNHM M.G.R. Database No. 4594 • 1 ♀; Athens ; 6 Aug. 1906; F.C. Bishopp leg.; USNM M.G.R. Database No. 1336 • 1 ♂; Bastrop ; 11 May 1954; R.H. Beamer leg.; KUNHM M.G.R. Database No. 4595 • 1 ♂; Colorado County; 12 May 1922; G.O. Wiley leg.; KUNHM M.G.R. Database No. 4593 • 2 ♀♀; Giddings ; 9 May 1954; R.H. Beamer leg.; KUNHM M.G.R. Database Nos 1423 , 4610 • 1 ♀; Lytle , Atascosa County; 1 Jun. 1951; H.E. Evans leg.; KUNHM M.G.R. Database No. 4613 • 1 ♀; New Boston ; 5 Jun. 1909; F.C. Bishopp leg.; USNM M.G.R. Database No. 1338 • 1 ♀; Paris ; 5 Aug. 1904; F.C. Bishopp leg.; USNM M.G.R. Database No. 1335 • 1 ♀; Willis ; 19 Jun. 1903; Bridwell leg.; USNM M.G.R. Database No. 1337 . – Virginia • 1 ♂; Blandy Station ; 1 Jul. 2008; M. Vandyke leg.; BIML • 1 ♂; Rappahannock River Valley National Wildlife Refuge , Richmond County; 38.0129° N, 76.8874° W; 17–18 Aug. 2009; R. Coston leg.; BIML USGS-DRO 137886 . – West Virginia • 4 ♀♀; Moncove Lake State Park , Monroe County; 37.6217° N, 80.3519° W; 30 Jul. 2008; S.M. Paiero leg.; DEBU debu01142283 to debu01142286 • 1 ♂; same data as for preceding; DEBU debu01142282 .

Non-preserved material

CANADA – Ontario • 1 ♀; Lansdowne, Leeds and the Thousand Islands ; 44.5110° N, 75.9933° W; 11 Aug. 2013; K. Hennige obs.; iNaturalist record #38798666 • 1 ♀; Tweed ; 44.4810° N, 77.3179° W; 30 Jul. 2022; J. Bartok obs.; iNaturalist record #128803190 .

USA – Arkansas • 1 ♂; Camp Robinson State Wildlife Management Area , Faulkner County; 5 Jun. 2023; “ czlittle ” obs.; iNaturalist record #165923253 . – Iowa • 1 ♂; Polk City ; 21 Aug. 2021; T. Grant obs.; iNaturalist record #92063440 . – New York • 1 ♂; Gouverneur ; 44.1185° N, 75.6767° W; 19 Jul. 2021; C. Wilson obs.; iNaturalist record #104480957 • 1 ♀; Tank Trail, Gouverneur ; 44.0695° N, 75.6932° W; 13 Jul. 2021; C. Wilson obs.; iNaturalist record #104482815 . – South Dakota • 1 ♀; North Alabama Bend Wildlife Area ( Vermillion ); 12 Jul. 2022; “ stenthesnake ” obs.; iNaturalist record #127900207 . – Wisconsin • 1 ♀; Madison ; 43.0886° N, 89.4304° W; 27 Jul. 2018; M. Nofsinger obs.; iNaturalist record #15114602 • 1 ♀; Sauk City; 19 Aug. 2021; “ natureman98 ” obs.; iNaturalist record #100182955 .

Redescription

MEASUREMENTS OF LECTOTYPE. Body length 10.9 mm; ITW 2.3 mm; head length 2.8 mm; head width 3.7 mm; fore wing length 8.5 mm (margins of both worn).

Both sexes

INTEGUMENT COLORATION. Dark brown to black except as follows. Mandible with apical half golden yellow and middle quarter in basal half reddish brown. Labrum partially, clypeus along lower margin, scape to some extent, and pedicel and F1 extensively orange. F2 with orange spot basally. Pronotal lobe to some extent in multiple non-type specimens, tegula, axilla with tip (entirely black in lectoallotype and multiple non-type specimens), coxae to tibiae to some extent, tarsi partially to entirely, metasomal terga laterally, pygidial plate, and metasomal sterna to some extent reddish brown. Fore wing membrane dusky subhyaline throughout, slightly darker beyond venation. Hind wing membrane dusky subhyaline to hyaline.

PUBESCENCE. Face with tomentum densest around antennal socket. Clypeus, upper paraocular and frontal areas, and vertexal area mostly exposed. Pronotal collar with tomentum uniformly bright yellow. Mesoscutum with well-defined paramedian band of bright yellow tomentum attaining anterior margin; pale tomentum otherwise mostly restricted to lateral and posterior margins. Mesopleuron with pale-yellow, appressed, branched setae; densely setose only just below scrobal groove and along posterior margin above base of mesocoxa (upper half otherwise sparsely setose); ventrolateral half nearly bare. Metanotum with tomentum uninterrupted, pale yellow laterally and almost entirely black medially. Propodeal triangle mostly glabrous, with (pale) setae restricted to small lateral patches. T1 with basal and apical transverse bands of bright yellow tomentum interrupted medially and subparallel, lateral longitudinal band broader than apical transverse band, discal patch trapezoidal (semicircular in some non-type specimens). T1–T4 with apical transverse bands complete and medially somewhat narrowed and removed from apical margins of terga, that of T2 bright yellow and without anterolateral extensions (with pair of very short and small anterolateral extensions in some non-type specimens), that of T3 pale yellow, that of T4 off-white.

SURFACE SCULPTURE. Labrum coarsely and densely (most i <1d) rugose-punctate. Clypeus densely punctate (most i <1d) but interspaces well defined, shining; with many small punctures among larger ones. Vertexal area densely punctate (most i ≤ 1d). Mesoscutum, mesoscutellum, axilla, and mesopleuron with punctures more or less equally dense and nearly contiguous (most i<1d). Mesopleuron with punctures similar in size throughout. Discs of metasomal terga with punctures very fine, dense (i≈ 1d), and evenly distributed; interspaces shining.

STRUCTURE. Labrum with pair of small subapical denticles, each preceded by discrete longitudinal ridge. Pronotal collar somewhat elongate (medial length ~ ¾ MOD). Mesoscutellum strongly bigibbous. Axilla extending beyond midlength of mesoscutellum but not as far back as its posterior margin; tip distinctly pointed, but mesally unattached to mesoscutellum for less than ⅓ medial length of axilla; lateral margin somewhat arcuate. Fore wing with three submarginal cells.

Female

T5 with concave apical margin and large patch of off-white tomentum on each side lateral to pseudopygidial area. Pseudopygidial area with triangular region of very short posteromedially directed golden setae. Pygidial plate apically truncate. S5 straight in lateral view, with apical fimbria of coppery bristle-like setae; metasomal sterna otherwise covered in brown tomentum.

Male

T5 with complete apical transverse band of off-white tomentum. T6 with small posteromedial patch of off-white tomentum in lectoallotype (absent in multiple non-type specimens). Pygidial plate apically rounded and slightly downturned, with basal transverse ridge rather ill-defined and lateral margin sinuate. S2–S3 with medially widely interrupted apical transverse bands of white tomentum. S4 with apical/ subapical fringe of dense, long (> 1 MOD), curved, brown setae, contrasting with apical transverse bands of white tomentum of preceding sterna.

Distribution

Ontario and much of the Eastern United States to the Great Plains ( Fig. 12P ).

Ecology

Host records

Among the specimens examined as part of Rightmyer’s (2006) dissertation was one T. simplex collected at the nest of a species of Hesperapis Cockerell, 1898 ( Hymenoptera : Melittidae : Dasypodainae ) and another collected at the nest of Svastra petulca (Cresson, 1879) ( Hymenoptera : Apidae : Eucerinae ) in Bastrop County, Texas.

Floral records

Robertson (1929), Mitchell (1962), Rightmyer (2006), images on iNaturalist, and labels of examined voucher specimens indicate that this species has been collected from the following flowering plant species:in Asteraceae , Amphiachyris sp. , Cirsium sp. , Coreopsis sp. , C. tinctoria Nutt. , Gaillardia sp. or spp., G. pulchella , Helenium sp. or spp., Helianthus sp. , H. annuus , H. divaricatus L., H. strumosus L., H. tuberosus L., Heterotheca camporum (Greene) Shinners , Liatris sp. , Ratibida columnifera , R. pinnata Barnhart , Rudbeckia hirta , R. hirta var. pulcherrima Farw. , Silphium integrifolium Michx., S. integrifolium var. laeve Torr. & A.Gray , Solidago sp. or spp., S. ohioensis Riddell , Vernonia sp. or spp., V. baldwinii Torr. , and V. missurica Raf. ; in Fabaceae , Dalea candida , D. purpurea , Eysenhardtia texana Scheele , and Lespedeza virginica (L.) Britton; in Lamiaceae , Origanum sp. , Pycnanthemum flexuosum Britton, Sterns & Poggenb., P. verticillatum var. pilosum (Nutt.) Cooperr. , and Teucrium canadense ; in Malvaceae , Callirhoe involucrata (Torr. & A.Gray) A.Gray ; and in Verbenaceae , Verbena sp. , V. hastata L. and V. stricta Vent.

Remarks

This species exhibits continuous variation in the shape of the T1 discal patch, which ranges from strongly trapezoidal to almost perfectly semicircular. Triepeolus simplex was not included in Romankova’s (2004) review of the Epeolini of Ontario and is herein newly reported from Canada.

Figures

Fig. 10. Metasoma of male, lateral view. A. Triepeolus simplex Robertson, 1903 (BOLD sample ID: QUBS0291G11; PCYU) showing S4 with apical/subapical fringe of dense, long (>1 MOD), curved setae (blue arrow). B. T. diffusus Rightmyer, 2008 (RAM pmae00146019) showing S4 with apical/ subapical fringe of dense, long (> 1 MOD), curved setae (blue arrow). C. T. rufoclypeus (Fox, 1891) (PCYU) showing S3–S5 each with apical/subapical fringe of dense, long (>1 MOD), curved setae (blue arrows). D. T. eumeniformis sp. nov., paratype (ECOSUR ECO-TA-E-41271) showing S4–S5 each with apical/subapical fringe of dense, long (> 1 MOD), curved setae (blue arrows).

Fig. 12A–D (continued on next page). Distribution maps. A. All species in the Triepeolus simplex group. B. T. apache sp. nov. C. T. eumeniformis sp. nov. D. T. hirsutus sp. nov. Approximate geographic ranges are indicated in orange and were estimated from occurrence records known to the authors (yellow and blue circles, with the latter indicating localities of DNA barcoded specimens).

Fig. 31. Triepeolus simplex Robertson, 1903. A, D. Female (BOLD sample ID: CMNTO_038; PCYU PYU-319). A. Habitus, lateral view. B. Female (DEBU debu01142285), habitus, dorsal view. C. Male (BIML USGS-DRO 137886), habitus, lateral view. D. Pseudopygidial area, dorsal view.

Fig. 25. Triepeolus paucipunctatus sp. nov., holotype, ♀ (UCBME M.G.R. Database No. 1216). A. Habitus, lateral view. B. Habitus, dorsal view. C. Head, frontal view. D. Pseudopygidial area, dorsal view.