Brachymelecta californica

Brachymelecta californica (Cresson, 1878)

Figs 1, 2A–B, 4B, 5, 6A–B, 7–8, 12A, 17

Melecta californica Cresson, 1878: 91 (♀, ♂); Cresson, 1916: 114 (♂) (lectotype designation). Melecta ? mucida Cresson, 1879: 205 (♂), syn. nov.

Melecta miranda Fox, 1893: 143 (♀).

Pseudomelecta pasadenensis Cockerell, 1910: 27 (♀).

Melecta sladeni Viereck, 1924: 15 (♀).

Proposed common name

California digger-cuckoo bee.

Diagnosis

The following morphological features in combination can be used to tell B. californica apart from all other Brachymelecta: the mesoscutum has a pair of anterior spots or (paramedian) bands of hairs darker than the surrounding off-white hairs (Fig. 5B); the mesoscutellum has a pair of short, mammiform tubercles (Fig. 5D); the fore wings are infuscate apically, with most cells as well as the membrane around the third submarginal crossvein (or second submarginal crossvein if the wing has only two submarginal cells) and second recurrent vein subhyaline (Fig. 5A–C); and T3 and T4 each have a medially interrupted fascia that is narrowed or interrupted (as opposed to continuously expanded) laterally, mesad the inner pair of anterolateral extensions (there are two such lobe-like extensions on each side) (Fig. 5A–C). Brachymelecta californica is most similar to B. interrupta, but in B. interrupta the fore wings are infuscate throughout except around the third submarginal crossvein and second recurrent vein, where they are subhyaline, and T3 and T4 each have a medially interrupted fascia that is broadened anterolaterally, that of T3 into the inner pair of anterolateral extensions. Additionally, in B. interrupta the lighter hairs covering the head, mesosoma, and metasoma range from pale yellow to yellow orange, whereas in B. californica they are off-white or very rarely pale yellow.

Material examined

Primary type material

CANADA • ♀, M. sladeni holotype; British Columbia, Summerland; 9 Aug. 1916; F.W.L. Sladen leg.; CNC 652.

USA • ♂, M. californica lectotype; California; “ H. Edwards, Behrens”; ANSP 2292 • ♀, P. pasadenensis holotype; Pasadena, Los Angeles County; 30 Apr. 1909; F. Grinnell Jr. leg.; CAS 15525 • ♂, M. ? mucida holotype; Nevada; H.K. Morrison leg.; ANSP 2294 • ♀, M. miranda holotype; South Dakota, Rapid City; J.T. Aldrich leg.; ANSP 10129.

Secondary type material

CANADA • 1 ♀, M. sladeni paratype; British Columbia, Westbank; 20 Jul. 1919; E.R. Buckell leg.; CNC 891698.

USA • 6 ♂♂, M. californica paralectotypes; California; “ H. Edwards, Behrens”; ANSP 2292-3 to 2292- 8 • 1 ♀, M. miranda paratype; South Dakota, Custer; J.T. Aldrich leg.; ANSP 10129.

DNA barcoded material

Available. Two BINs:

BOLD:AAC6481. Specimens examined and sequenced:

CANADA • 1 ♀; British Columbia, White Lake (Okanagan Falls), Regional District of Okanagan- Similkameen; 49.3028° N, 119.6286° W; 17 Aug. 2008; L.R. Best leg.; BOLD sample ID: LRBBC1015; PCYU LRB-445.

USA • 1 ♂; Arizona, Catalina Hwy (Santa Catalina Mountains), Pima County; 32.3636° N, 110.7128° W; 29 May 2015; T.M. Onuferko leg.; BOLD sample ID: CCDB-34570 A09; PCYU • 1 ♀; Arizona, Catalina Hwy (Santa Catalina Mountains), Pima County; 32.3242° N, 110.7064° W; 10 May 2016; T.M. Onuferko leg.; BOLD sample ID: CCDB-34570 B02; PCYU • 1 ♂; Arizona, Near Desert Botanical Garden (Phoenix), Maricopa County; 31 May 2018; T.M. Onuferko leg.; BOLD sample ID: CCDB- 34570 A11; PCYU • 1 ♂; Arizona, SE of Willcox, Cochise County; 32.2350° N, 109.7785° W; 30 Aug. 2016; L. Packer leg.; BOLD sample ID: CCDB-34570 A05; PCYU • 1 ♀; Colorado, Cortez, Montezuma County; 37.3570° N, 108.5900° W; 27 Jul. 2012; J. Gibbs and C.S. Sheffield leg.; BOLD sample ID: CCDB-06707 F05; PCYU PCYU-GS-07:870 • 1 ♀; New Mexico, NM 15 (16.7 mi N of Silver City), Gila National Forest; 32.9462° N, 108.1978° W; 5 Sep. 2015; R.R. Ferrari leg.; BOLD sample ID: CCDB-34570 A03; PCYU • 1 ♀; Oregon, Hwy 140, Klamath County; 42.2132° N, 121.8306° W; 2 Jul. 2007; J. Gibbs and C.S. Sheffield leg.; BOLD sample ID: 07-OR-1265; PCYU PYU-2308.

BOLD:AAC6482. Specimens examined and sequenced:

USA • 1 ♂; California, Isabella Walker Pass Road (10.4 mi E of Onyx), Kern County; 35.6658° N, 118.0386° W; 12 Sep. 2015; T.M. Onuferko and S. Tessier leg.; BOLD sample ID: CCDB-34570 A01; PCYU • 1 ♀; California, Near Descanso Gardens (La Cañada Flintridge), Los Angeles County; 25 May 2018; T.M. Onuferko leg.; BOLD sample ID: CCDB-34570A07; PCYU • 1 ♀; Idaho, Hwy 20 (20 km E of Mountain Home), Elmore County; 43.2842° N, 115.4765° W; 27 May 2007; J. Gibbs and C.S. Sheffield leg.; BOLD sample ID: 07-ID-1195; PCYU PYU-1208 • 1 ♀; New Mexico, Cloudcroft, Otero County; 32.9574° N, 105.7447° W; 11 Aug. 2007; J. Gibbs and C.S. Sheffield leg.; BOLD sample ID: 07-NM- 2108; PCYU PYU-3519 • 1 ♂; New Mexico, Hwy 152, Sierra County; 32.8949° N, 107.7399° W; 12 Aug. 2007; J. Gibbs and C.S. Sheffield leg.; BOLD sample ID: 07-NM-2109; PCYU PYU-3530.

Non-barcoded material

CANADA • 1 ♀; Alberta, Bull Trail Park (Lethbridge); 49.6933° N, 112.8703° W; 9 Jul. 2020; M. Buck leg.; RAM PMAE00156227 • 1 ♀; Alberta, Bull Trail Park (Lethbridge); 49.6964° N, 112.8714° W; 9 Jul. 2020; M. Buck leg.; RAM PMAE00156145 • 6 ♀♀; Alberta, Dry Island Buffalo Jump Provincial Park, Kneehill County; 51.9417° N, 112.9481° W; 20 Jul. 2016; M. Buck leg.; RAM • 1 ♀; Alberta, Dry Island Buffalo Jump Provincial Park, Kneehill County; 51.9425° N, 112.9664° W; 20–21 Jul. 2016; M. Buck leg.; RAM • 2 ♂♂; Alberta, Gariepy (Edmonton); 53.4903° N, 113.6194° W; 3 Jun. 2018; M. Buck leg.; RAM • 2 ♀♀, 1 ♂; same collection data as for preceding; 16 Jun. 2018; RAM • 1 ♀; Alberta, Helen Schuler Nature Reserve (Lethbridge); 49.7008° N, 112.8603° W; 13 Jul. 2020; M. Buck leg.; RAM PMAE00156567 • 1 ♀; Alberta, Lethbridge; 11 Aug. 1944; O. Peck leg.; CNC 891702 • 1 ♀; Alberta, Milk River (Weir Bridge), Warner County; 49.1042° N, 111.7000° W; 24 Jul. 2020; M. Buck leg.; RAM PMAE00157991 • 2 ♀♀; Alberta, Near Capilano Foot Bridge (Edmonton); 53.5642° N, 113.4192° W; 17 Jun. 2018; M. Buck leg.; RAM • 1 ♂; Alberta, Redcliff; 50.0539° N, 110.7758° W; 28 Jun. 2017; M. Buck leg.; RAM • 1 ♀; same collection data as for preceding; 29 Jun. 2017; RAM • 1 ♂; Alberta, Scandia; 21 Jul. 1928; F.W. Barnes leg.; CNC 891692 • 1 ♀; Alberta, Terwillegar Park (Edmonton); 53.4775° N, 113.6189° W; 15 Jul. 2018; M. Buck leg.; RAM • 7 ♂♂; Alberta, Wild Horse; 10 Aug. 1927; H.E. Gray leg.; CNC 891691, 891693 to 891696, 891704, 899632 • 2 ♀♀; Alberta, Writing-on- Stone Provincial Park (Coffin Bridge), Warner County; 49.1033° N, 111.8903° W; 15 Jul. 2020; M. Buck leg.; RAM PMAE00156796, PMAE00156797 • 1 ♀; Alberta, Writing-on-Stone Provincial Park (Davis Coulee), Warner County; 49.0708° N, 111.6281° W; 22 Jul. 2020; M. Buck leg.; RAM PMAE00157617 • 2 ♀♀; Manitoba, Treesbank, Municipality of Glenboro-South Cypress; 49.6350° N, 99.6040° W; 1 Jul. 2018; Manitoba Conservation Data Centre leg.; WRME JBWM0415546, JBWM0415590.

MEXICO • 1 ♂; Baja California Sur, San Hilario; 5 Nov. 1968; E.L. Sleeper and F.J. Moore leg.; CAS • 1 ♂; Baja California Sur, Santa Victoria La Laguna; 20 or 23 Oct. 1968; E.L. Sleeper and F.J. Moore leg.; CAS • 2 ♀♀, 7 ♂♂; Baja California Sur, Sierra La Laguna; 1 Sep. 1977; R. Westcott leg.; CAS • 1 ♀; Distrito Federal, Xochimilco; 18 Aug. 1962; H.E. Milliron; CNC 394149 • 1 ♀; Sinaloa, Mazatlán; Feb. ??53; CAS • 1 ♂; Sonora, Gran Desierto de Altar; 20 Mar. 2018; H. Knight leg.; CSUC.

USA • 1 ♂; Arizona, 4 mi E of Willcox, Cochise County; 27 Aug. 2007; G. Rowe leg.; PCYU • 1 ♀; Arizona, East Moonlight Road, Cochise County; 32.2388° N, 109.7651° W; 14 Aug. 2007; J. Gibbs and C.S. Sheffield leg.; PCYU PYU-5972 • 1 ♀; Arizona, Rustler Park (Chiricahua Mountains), Cochise County; 31.9039° N, 109.2792° W; 11 Aug. 2007; M. Buck leg.; DEBU debu00291918 • 2 ♀♀; California, 13 mi W of Coalinga; 30 Jul. ??59; CNC 891731, 891732 • 1 ♀; California, 3 mi N of Coalinga; 29 Jul. 1954; F.M. Hull leg.; CNC 891744 • 5 ♀♀; California, 28 km NE of Foresthill (Tahoe National Forest), Placer County; 39.1856° N, 120.6058° W; 8 Jun. 2009; M. Buck leg.; RAM • 1 ♀; California, 30 km NE of Foresthill (Tahoe National Forest), Placer County; 39.1894° N, 120.5756° W; 8 Jun. 2009; M. Buck leg.; RAM • 1 ♀; California, Antioch; Oct. 1938; J.A. Downes leg.; CNC 846577 • 2 ♂♂; California, CA-20 1.7 km W of Jct CA-16, Colusa County; 39.0133° N, 122.3792° W; 9 Jun. 2009; M. Buck leg.; RAM • 1 ♂; California, Cache Creek Natural Area, Cowboy Camp; 38.9978° N, 122.3558° W; 9 Jun. 2009; M. Buck leg.; RAM • 1 ♀; California, Helendale, San Bernardino County; 16 May 1955; W.R. Richards leg.; CNC 891690 • 1 ♀; same collection data as for preceding; 21 May 1955; W.R.M. Mason leg.; CNC 891736 • 1 ♀; California, Mill Creek, San Bernardino Mountains; 31 Aug. 1930; C.D. Michener leg.; CNC 891705 • 1 ♀; California, Mojave; 15 Oct. ??25; R. Hopping leg.; CNC 891703 • 3 ♀♀; California, Mojave Desert; 15 Oct. 1925; J.M. Swaine leg.; CNC 891697, 891700 to 891701 • 1 ♀; California, Peavine Ridge Road, El Dorado County; 38.7964° N, 120.4297° W; 14 Jun. 2009; M. Buck leg.; RAM • 1 ♂; California, Sierra Nevada; ANSP • 1 ♂; California, Split Mountain (Anza-Borrego Desert State Park), San Diego County; 1 Apr. 1955; J.E.H. Martin leg.; CNC 891713 • 1 ♂; California, UCR Botanic Gardens (Riverside), Riverside County; 26 Jun. 1984; S.L. Heydon leg.; INHS 387473 • 1 ♀; Idaho, Hwy 75 (5 km N of Ketchum), Blaine County; 43.7630° N, 114.4003° W; 25 Jun. 2007; J. Gibbs and C.S. Sheffield leg.; PCYU PYU-1515 • 2 ♀♀, 6 ♂♂; Nevada; ANSP • 1 ♂; Nevada, Pyramid Lake (south shore), Washoe County; 39.8444° N, 119.4400° W; 13 Jun. 2009; M. Buck leg.; RAM • 1 ♀; New Mexico, Hwy 152, Sierra County; 32.8949° N, 107.7399° W; 12 Aug. 2007; J. Gibbs and C.S. Sheffield leg.; PCYU PYU-2391 • 1 ♂; New Mexico, Hwy 152, Sierra County; 32.8949° N, 107.7399° W; 12 Aug. 2007; J. Gibbs and C.S. Sheffield leg.; PCYU PYU-2392 • 1 ♀; Oregon, Fish Lake (near Steens Mountain), Harney County; 42.7419° N, 118.6461° W; 6 Aug. 2005; J. and A. Skevington leg.; CNC 891706 • 1 ♀; Oregon, Hwy 140, Klamath County; 42.2132° N, 121.8306° W; 2 Jul. 2007; J. Gibbs and C.S. Sheffield leg.; PCYU PYU-2292 • 3 ♀♀; Oregon, Hwy 26, Crook County; 44.4721° N, 120.4197° W; 28 Jun. 2007; J. Gibbs and C.S. Sheffield leg.; PCYU PYU-2111, PYU-2676, PYU-2682 • 1 ♀; Oregon, Hwy 97, Klamath County; 42.1224° N, 121.8273° W; 2 Jul. 2007; J. Gibbs and C.S. Sheffield leg.; PCYU PYU-2276 • 1 ♂; Texas, 23 mi W of Fort Davis; 1 Jun. 1959; F. McAlpine leg.; CNC 891707 • 1 ♀; Texas, Big Bend National Park, Boquillas; 17 May 1959; W.R.M. Mason leg.; CNC 891724 • 3 ♂♂; Texas, Big Bend National Park, Dagger Flats; 11 May 1959; W.R.M. Mason leg.; CNC 891721, 891722, 891727 • 1 ♀; Texas, Big Bend National Park, Nine Point Draw; 15 May 1959; W.R.M. Mason leg.; CNC 891725 • 1 ♂; Texas, Big Bend National Park, Panther Junction; 16 May 1959; J.F. McAlpine leg.; CNC 891723 • 1 ♀; Texas, Devils River, Del Rio; 26 Apr. 1959; J.F. McAlpine leg.; CNC 891715 • 1 ♀; Texas, Dickinson, Galveston County; Jun. 1929; F.M. Hull leg.; CNC 891734 • 1 ♀; Texas, Las Burras Canyon at FM-170, Presidio County; 29.3903° N, 104.1428° W; 28 Apr. 2019; M. Buck leg.; RAM • 1 ♂; Texas, near Point of Rocks (10 mi W of Fort Davis); 29 May 1959; F. McAlpine leg.; CNC 891720 • 1 ♂; Utah, 24 mi S of Hanksville; 18 Jul. 1968; J.E.H. Martin leg.; CNC 891733 • 3 ♂♂; same collection data as for preceding; 23 Jul. 1968; CNC 891728 to 891730 • 1 ♂; Utah, Fairview Ranch (13 mi S of Hanksville); 2–3 Aug. 1968; H.F. Howden leg.; CNC 891726.

Redescription

Male

MEASUREMENTS. Length 9.9 mm; ITW 2.6 mm; head length 2.7 mm; head width 3.3 mm; fore wing length 9.2 mm.

INTEGUMENT COLORATION. Dark brown to black except as follows. Mandible with apical third golden yellow. Mandible with middle third, legs, excluding black tibial spurs, and much of metasoma reddish brown. Tegula amber. Fore wing dusky apically, with most cells and around third submarginal crossvein and second recurrent vein subhyaline. Hind wing hyaline, slightly dusky beyond venation.

PUBESCENCE. Face with hairs densest around antennal socket, predominantly off-white but dark brown/ gray in lower paraocular area. Clypeus bare in M. californica lectotype, with many hairs rubbed off, but with dense hairs in multiple paralectotypes and non-type specimens and M. ? mucida holotype. Upper paraocular and frontal areas and vertexal area (except along preoccipital ridge) mostly exposed. Head with dense, erect hairs along preoccipital ridge off-white except for pair of dark brown/gray patches, each behind lateral ocellus and in front of paramedian band. Genal beard hairs predominantly off-white. Mesoscutum sparsely hairy except densely hairy anteriorly and along margins, with hairs predominantly off-white except for dark brown/gray paramedian band. Axilla with conspicuous patch of black hairs. Mesoscutellum, metanotum, and propodeum with erect, predominantly off-white hairs. Mesopleuron with upper half covered in dense, off-white hairs greatly obscuring underlying integument, with large circular patch of sparser, dark brown/gray to black hairs not obscuring underlying integument occupying much of ventrolateral half, and with predominantly off-white hairs somewhat obscuring underlying integument ventrally around margin. Legs, from coxae to tarsi, with appressed and erect off-white hairs, ventrally with golden-yellow hairs. Profemur with posteroventral fringe of dense, off-white hairs. Protibia and metatibia each with two bands or spots of short, appressed off-white hairs, one in basal half and one on apical margin. Mesotibia with patch of very dense short, appressed off-white hairs, occupying nearly entire dorsal surface. T1–T5 with well-defined, medially interrupted apical fasciae, each with pair of lobe-like anterolateral extensions on each side with erect among appressed off-white hairs. T3–T5 each with fascia more widely removed from apical margin and laterally narrowed or interrupted, mesad the inner pair of anterolateral extensions. T6 almost completely retracted under T 5 in M. californica lectotype, but with paired patches of off-white tomentum in paralectotype and multiple non-type specimens. Exposed metasomal sterna mainly with short, appressed off-white hairs. S4 and S5 each with apical/subapical fringe of dense, long, curved, coppery to silvery hairs.

SURFACE SCULPTURE. Labrum sparsely punctate (many i>2d). Clypeus with upper half densely punctate (most i≤1d), lower half more sparsely punctate (many i>1d). Small impunctate shiny spot lateral to lateral ocellus. Mesoscutum and mesoscutellum with coarser punctures than metasomal terga. Mesoscutum densely punctate (most i≤1d) except for small impunctate shiny spot between paramedian band and parapsidal line and in posterior half between midline and parapsidal line, where more sparsely punctate (many i>1d). Mesoscutellum with coarser punctures than mesoscutum, densely punctate (most i≤1d) except medially (between pair of mammiform tubercles), where somewhat sparsely punctate (i≤2d). Mesopleuron densely punctate (most i<1d) but with most interspaces well-defined, shining. Discs of metasomal terga with punctures very fine, sparse (most i>1d), interspaces dull due to tessellate surface microsculpture.

STRUCTURE. Mandible tridentate, with small inner tooth approximately ⅓ length of mandible from base and equally small inner tooth approximately ⅓ length of mandible from apex as well as usual large apical tooth (rutellum) (difficult to see in M. californica lectotype because mandibles closed; described from paralectotypes, non-type specimens, and M. ? mucida holotype). Maxillary palpus with four palpomeres (mouthparts not extended in M. californica lectotype; described from paralectotypes and non-type specimens). Scape with greatest length 1.9 × greatest width. F2 wider than long (L/W ratio = 0.8). Mesoscutellum strongly bigibbous, with pair of short, apically flattened mammiform tubercles. Lateral surface of propodeum posterior to spiracle with rugose crescent ridge, strongly carinate above and joining anterior lip of spiracle. Fore wing with two or three submarginal cells (in M. californica lectotype, second submarginal crossvein of left fore wing incomplete, that of right fore wing complete). T7 distinctly notched medially between pair of small medioapical projections.

Female

Description as for male except for usual secondary sexual characters and as follows: scape longer, with greatest length 2.3 × greatest width; mesotibia dorsally with off-white hairs forming small band or spot, nearer the base than apex; T6 with narrow, V-shaped but apically rounded pygidial plate with median longitudinal ridge and without patches of off-white tomentum; S4 and S5 apically/subapically without dense, long, curved, coppery to silvery hairs.

Distribution

Brachymelecta californica is the most widely distributed member of its genus, ranging from Western Canada to southern Mexico west of the Isthmus of Tehuantepec (Fig. 4B). Although this species has been recorded from the Eastern United States (Mitchell 1962), it is much more common in the west, with few known records east of the Mississippi River. This is the only species of Brachymelecta known to occur in Canada.

Ecology

Host records

Brachymelecta californica has been reared from the nests of multiple species of Anthophora, including A. abrupta Say, 1837, A. bomboides stanfordiana Cockerell, 1904 (a junior synonym of A. bomboides Kirby, 1838), A. edwardsii Cresson, 1878, A. linsleyi Timberlake, 1941, A. neomexicana (a junior synonym of A. bomboides), A. occidentalis Cresson, 1869, and A. urbana Cresson, 1878 (Hicks 1926; Linsley & McSwain 1942; Linsley 1943; Torchio & Trostle 1986; Rozen 1991). Additionally, Orr et al. (2016) documented the emergence of adults of this cuckoo bee species from nests of A. pueblo Orr, 2016.

Floral records

Although known to visit a very large variety of flowers, in a survey by P.H. Timberlake Brachymelecta californica was found to be most abundant on flowers of various Asteraceae (Linsley 1939). His floral records, based on collections at a single locality in Riverside, California, USA, are as follows: Brassica incana Ten. (Brassicaceae), Coreopsis lanceolata L. (Asteraceae), Croton setigerus Hook. (Euphorbiaceae) (as Eremocarpus setigerus), Cryptantha Lehm. ex G. Don (Boraginaceae), Duranta erecta L. (Verbenaceae) (as D. plumieri), Encelia farinosa A.Gray ex Torr. (Asteraceae), Ericameria palmeri (A.Gray) H.M.Hall (Asteraceae), Eriogonum fasciculatum Benth. (Polygonaceae), E. gracile Benth., Gutierrezia californica (DC.) Torr. & A.Gray (Asteraceae), Hemizonia paniculata A.Gray (Asteraceae), Lepidospartum squamatum (A.Gray) A.Gray (Asteraceae), Marrubium L. (Lamiaceae), Phacelia distans Benth. (Boraginaceae), Pluchea camphorata (L.) DC. (Asteraceae), Senecio flaccidus var. douglasii (DC.) B.L.Turner & T.M.Barkley (Asteraceae) (as S. douglasii), and Trichostema lanceolatum Benth. (Lamiaceae).

Hurd (1953) reported this species on Eysenhardtia polystachya (Ortega) Sarg. (Fabaceae) and Hurd et al. (1980) on Helianthus annuus L. (Asteraceae) and H. gracilentus A.Gray. Floral records from data contributors to Discover Life (Ascher & Pickering 2020) compiled by J. Pickering are as follows: Adenostoma Hook.&Arn.(Rosaceae), Aster L.(Asteraceae), Astragalus L.(Fabaceae), Baileya Harv.&A. Gray ex A. Gray (Asteraceae), Bebbia juncea (Benth.) Greene (Asteraceae), Chrysothamnus viscidiflorus (Hook.) Nutt. (Asteraceae), Cirsium vulgare (Savi) Ten. (Asteraceae), Clarkia Pursh (Onagraceae), Ericameria nauseosa (Pall. ex Pursh) G.L.Nesom & G.I.Baird, Ericameria parryi (A.Gray) G.L.Nesom & G.I.Baird, Eriodictyon californicum (Hook. & Arn.) Decne. (Boraginaceae), Gaillardia Foug. (Asteraceae), Grindelia Willd. (Asteraceae), Gutierrezia sarothrae (Pursh) Britton & Rusby, Horkelia Cham. & Schltdl. (Rosaceae), Larrea tridentata (Sessé & Moc. ex DC.) Coville (Zygophyllaceae), Lonicera L. (Caprifoliaceae), Lorandersonia linifolia (Greene) “Urbatsch, R.P.Roberts & Neubig” (Asteraceae) (as Chrysothamnus linifolius), Melilotus officinalis (L.) Pall. (Fabaceae), Melilotus albus Medik. (as M. alba), Monardella Benth. (Lamiaceae), Palafoxia arida B.L.Turner & M.I.Morris (Asteraceae), Penstemon cyananthus Hook. (Plantaginaceae), Petrophytum caespitosum (Nutt. ex Torr. & A.Gray) Rydb.(Rosaceae) (as Petrophyton caespitosum), Phacelia crenulata Torr.ex S.Watson, P.hastata Douglas ex Lehm., Salsola kali L. (Amaranthaceae), Salvia L. (Lamiaceae), Sedum stenopetalum Pursh (Crassulaceae), Senecio flaccidus Less. (as S. longilobus), Solidago L. (Asteraceae), Sphaeralcea orcuttii Rose (Malvaceae), Stanleya pinnata (Pursh) Britton (Brassicaceae), Syrmatium decumbens (Benth.) Greene (Fabaceae) (as Lotus nevadensis), Tamarix L. (Tamaricaceae), Tetradymia DC. (Asteraceae), and Verbesina encelioides (Cav.) Benth. & Hook. f. ex A.Gray (Asteraceae). Images on iNaturalist (https://www.inaturalist.org) show this species visiting Echinacea purpurea (L.) Moench (Asteraceae) and images on BugGuide (https://bugguide.net) show it visiting Achillea millefolium L. (Asteraceae), Baccharis salicina Torr.&A.Gray(Asteraceae), Centaurea nigra L. (Asteraceae), Chorizanthe staticoides Benth. (Polygonaceae), Cirsium wheeleri (A.Gray) Petr., Echinacea pallida (Nutt.) Nutt., Erodium cicutarium (L.) L’Hér. (Geraniaceae), Lantana L. (Verbenaceae), Osteospermum L. (Asteraceae), and Rosmarinus officinalis L. (Lamiaceae). Labels of examined voucher specimens further indicate that this species has been collected from Chilopsis D. Don (Bignoniaceae) and Sisymbrium loeselii L. (Brassicaceae).

Remarks

The holotype of M. ? mucida generally agrees with the diagnosis for B. californica provided herein. Additionally, examination of the dissected terminalia revealed that the hidden sterna and genitalia of the M. ? mucida holotype fall within the range of morphological variation observed among the five other specimens of B. californica that were dissected, including two M. californica paralectotypes. One notable feature unique to B. californica and shared by all dissected specimens (including the M. ? mucida holotype) is that S7 has long setae along its entire posterior margin (Fig. 6A–B). By contrast, in B. haitensis S7 has a tuft of dense setae posteromedially (Fig. 6C) and in B. interrupta and B. larreae S7 has only a few short setae posteromedially (Fig. 6D–E). In the M. ? mucida holotype, S8 is apparently damaged/split anteromedially, and thus somewhat distorted, but otherwise closely resembles that of other specimens of B. californica (Fig. 6A–B). No differences were found in the morphology of the genital capsule between the M. ? mucida holotype and other specimens of B. californica, but the genitalia are also highly similar among the six species in the genus.

The only diagnostic features that seemingly support B. mucida as a separate species include the presence of two submarginal cells on each of the two fore wings (Fig. 7A, C) and pale tomentum that obscures almost the entire dorsal surface of the metasoma (Fig. 7A–B). However, specimens of B. californica in which both fore wings have two submarginal cells are known(e.g., Fig.8A), and in multiple paralectotypes (Fig. 8B–C) and even the lectotype of M. californica, the second submarginal crossvein is incomplete in one wing, resulting in two submarginal cells, and complete in the other, resulting in three. Recently, a specimen of B. californica was collected that, like the M. ? mucida holotype, has abundant pale tomentum covering the surface of the metasomal terga (Fig. 8D). This specimen has been barcoded (BOLD sample ID: CCDB-34570 A03) and its sequence assigned to the BIN BOLD:AAC6481. However, the hairs on each tergum are not uniformly dense, such that distinct apical fasciae are still visible on T1–T5 (Fig. 8D). Close examination of the dorsal surface of the metasoma of the M. ? mucida holotype also revealed the presence of an apical fascia on each exposed metasomal tergum comprised of short, appressed, branched pale hairs slightly denser than those covering the disc (Fig. 7A–B). Hence, the anatomical features previously considered to be diagnostic for B. mucida fall within the range of variation observed within B. californica, so the former is herein synonymized under the latter.

In the original description, Fox (1893) described Melecta miranda (now an established junior synonym of B. californica, Hurd & Linsley 1951) from an unindicated number of specimens from Rapid City and Custer, South Dakota. In the ANSP entomological collection, one specimen from Rapid City, SD bears a red label that says “TYPE No. 10129” and is in the primary type collection whereas another from Custer, SD bears a blue label that says “ PARATYPE 10129” (the catalog number is the same for both specimens) and is in the regular collection. Although in the original description it is not indicated which specimen is the primary type, that which bears the red type label, which does not say paratype, is presumed to be the holotype as there is no indication that the species was described from more than the two specimens.

Barcoded specimens identified as B. californica (agreeing with the diagnosis for the species presented herein) were assigned one of two BINs (vide supra), which are each other’s nearest neighbors. Despite a barcode sequence divergence of 4.9% between the two MOTUs (see Supp. file 3: fig. S1), which are largely sympatric (see Fig. 4B), no consistent morphological differences were found (including in the dissected terminalia of two males that were assigned separate BINs, which fall within the range of morphological variation observed within this species). In all barcoded specimens, both fore wings have three submarginal cells, so the MOTUs cannot be identified by the number of submarginal cells on the fore wing, which in B. californica may differ between the left and right sides of the same specimen anyway.

Melecta miranda, now synonymous with B. californica, was originally described as a separate species because of its larger body size (15.2 mm in length, excluding the protruding sting), but barcoded specimens assigned separate BINs exhibit much overlap in body length (9.9–12.1 mm for BOLD BIN AAC6481 vs 9.1–10.5 mm for AAC6482), so body size could not be linked to haplotype. Pseudomelecta pasadenensis, now synonymous with B. californica, was described as separate from B. californica and M. miranda (as P. californica and P. miranda) on the basis of exhibiting tufts of black hair above the antennal sockets as well as in the lower paraocular area (Cockerell 1910), but barcoded specimens exhibiting this feature were divided between the two groups with separate BINs. Linsley (1939) further separated B. californica (as M. californica) from P. pasadenensis (as M. pasadenensis) by whether the T1 basal declivity has a fascia (said to be present in the former and absent in the latter). However, both haplotypes are represented by specimens in which T1 has a basal fascia. Viereck (1924) described M. sladeni as a new species superficially similar to M. miranda, the primary difference being that in the former the mammiform tubercles of the mesoscutellum are more similar to those of M. (now B.) interrupta. Having examined the primary types of M. interrupta, M. miranda, and M. sladeni, we conclude that the mesoscutella of the latter two are more similar to one another than either is to the mesoscutellum of the lectotype of M. interrupta. There also does not appear to be any consistent difference in the form of the mesoscutellum between specimens of the two haplotypes. Given that the observed morphological variation is continuous and that it is possible for real species to have split (i.e., multiple) BINs (Ratnasingham & Hebert 2013; see Ferrari 2017 for several examples within the bee genus Colletes Latreille, 1802 (Hymenoptera: Colletidae: Colletinae)), we recognize both series of barcoded specimens as a single species, B. californica, one in which intraspecific barcode sequence divergence is higher than might usually be expected among conspecifics.