Anthophora (Micranthophora) rhodothorax Michener 1936
Creators: name: Orr, Michael C.
name: Pitts, James P.
name: Griswold, Terry
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Apidae
Anthophora
Anthophora rhodothorax

description: Anthophora (Micranthophora) rhodothorax Michener, 1936
(Figs. 42D, 47D, 52D, 57D, 62D, 67D, 72D, 77D)
Anthophora rhodothorax Michener, 1936: 94 (holotype: ♂; Idyllwild, San Jacinto Mountains, CA, USA; coll. C.D. Michener, 12 Aug. 1934, at Asteraceae; CASENT, type 4717).
Anthophora emarginata Timberlake, 1937: 11 (holotype: male; Riverside, CA, USA; coll. Timberlake, 10 Sep. 1929, at Corethrogyne filaginifolia; AMNH, accession 35342). Syn. Michener, 1951 (by Timberlake).
Diagnosis. Males may be determined by the following character combination: supraclypeus with maculation usually rectangular; terga shiny between punctures; T7 without medial longitudinal carina, lateral projections moderately sharp but short, and medial projections long and rounded at tips (Fig. 62D); S5 with thick light erect setal patches (Fig. 38B); and S6 with medial emargination slightly filled by transparent integument (similar to Fig. 38B). Females may be determined by the following character combination: galea with long setae bent at tips (Fig. 33C), surface tessellate and dull; mandible with inferior tooth small but clearly angled off main blade (Fig. 42D); supraclypeus with strong maculation, varying from amorphous to rectangular; scutum shiny, with impunctate areas; and T5 with appressed setae.
Male description. Head: Facial maculations pale to richly yellow. Galea reaching between front and rear of foretrochanter in repose; light to dark brown; strongly tessellate, with very weak reflections if any; typically with short, straight setae sparsely throughout. Mandible with inferior tooth large and ovular, running parallel to main blade or nearly so; maculated from base to start or about middle of inferior tooth (Fig. 52D). Labral rim tridentate; fully maculated. Clypeal maculation a band, usually reaching lateral sides, filling over half of clypeal height medially and sometimes narrowly connected to top of clypeus (Fig. 52D); punctation significantly sparser within maculation than without. Paraocular area immaculate. Supraclypeal area maculated; strong, but somewhat amorphously triangular. Scape maculated; fully along length and most of width below. Mesosoma: Scutum shiny; with distinct impunctate areas, sometimes invaded by sparse punctures. Tegula opaque to translucent, dark to medium brown. Basitibial plate absent. Metasoma: T1 covered in appressed setae; T2–T6 with variably thick appressed setal bands, sometimes undulate. Terga weakly tessellate to smooth between punctures, with moderate to strong reflections; often apparent through appressed setae. Tergal rims transparent, tan. Male T7 (Fig. 62D) without medial longitudinal carina, setae sometimes obscuring area; lateral projections moderately recurved, sharp but somewhat triangularly so; medial projections moderately long and gradually narrowing to relatively broad, rounded tips. Male S5 (Fig. 38B) with dense and light erect setal patches. Male S6 resembling Fig. 38B, clearly medially emarginate with slight transparent integumental infill near base, but more extensively filled by transparent integument and with distinctly denser medial setal tuft. Male S7 (Fig. 67D) with setae fully banding S7 around midpoint of length; widening from midpoint to tip, apical half widest clearly before rounded lateral tips; apical half hexagonal, rim roughly flat. Male S8 (Fig. 72D) lateral projections reduced but distinct; medial projection narrowing to tip, apically emarginate. Male genital capsule (Fig. 77D) with outer corners, where gonocoxite tips curve inward, marked by broad flange of about 90 degrees or greater, best seen in profile; from corner to apex, in profile, gonocoxite with low secondary bump but relatively unmodified overall; tip, in profile, small but pointed and abruptly bent ventrally; gonostylus tip position significantly exceeding that of gonocoxite, measured from above along primary axis of latter. Pubescence: See Fig. 57D. Appears gray or dark tan to orange overall. Setae gold to orange, with limited whitish setae near venter, except as follows: vertex with or without dark intermix; scutum almost always with some dark intermixing, usually strongest medially; tergal basal zones dark.
Female similar to male, except: Head: Facial maculations more often richly yellow. Galea with long, bent-tipped setae (Fig. 33C). Mandible with inferior tooth ridge-like but expanded, clearly angled off main blade (Fig. 42D). Labral rim rounded. Supraclypeal maculation more amorphous. Scape immaculate. Mesosoma: Scutal impunctate areas sometimes absent. Midtibial spur apically curved; tan to orange. Basitibial plate circular but slightly flattened distally, otherwise teardropped overall. Metasoma: T1–T4 setae highly variable, from thin bands to fully covered with appressed setae, undulate or not; T5 with extensive appressed setae. T4 impunctate rim of short length medially, usually barely visible. Anal fimbria triangular, covering less than third to greater than third but clearly less than half of T5 length medially. Pubescence: See Fig. 47D. Hindbasitarsal brush medium to dark brown; anal fimbria highly variable, light to blackish; S5 with limited apicomedial dark, most often hidden beneath light.
Distribution. See Fig. 27. Appears rare to uncommon. Present in USA: California, likely Oregon; Mexico: likely Baja California Norte. Found in varied chaparral and grassland habitats, often mid-elevational. Ecoregion records include: 7 ecoregions total: California coastal sage and chaparral (40=32.3%), California Central Valley grasslands (40=32.3%), California interior chaparral and woodlands (28=22.6%), California montane chaparral and woodlands (7=5.6%), Klamath-Siskiyou forests (6=4.8%), Sierra Nevada forests (2=1.6%), Eastern Cascades forests (1≤1%).
Phenology. Recorded from June–October, almost exclusively fall, most common in September. Univoltine, two summer records from California’s Coastal Range possibly opportunistic emergences.
Nesting biology. Unknown.
Floral specialization. Likely specialist on Asteraceae, possibly narrowly specialized on Corethrogyne filaginifolia, but likely also using physically similar hosts. Modified pollen-gathering galeal setae may improve efficiency near start of bloom when flowers are less open. Primary recorded visits by three females include: Family Asteraceae (100%); Genus Corethrogyne (33%); Gutierrezia (33%), “ Aster ” (33%) [“ Aster ” was used prior to recent taxonomic changes, can refer to a number of genera]; Species Corethrogyne filaginifolia (33%); Gutierrezia sarothrae (33%). 11 total floral records include: Asteraceae (8 ♂ 3 ♀): Aster sp. 1 ♂ 1 ♀, Corethrogyne filaginifolia 4 ♂ 1 ♀, Erigeron sp. 1 ♂, Gutierrezia californica 1 ♂, Gutierrezia sarothrae 1 ♀, Senecio douglasii 1 ♂.
Comments. Anthophora rhodothorax has several forms. Although most specimens throughout its range have well-defined tergal appressed setal bands, this is not the case in some relatively montane areas in Northern California, where the terga are covered in appressed setae. The overall setal color also appears to vary from gray to brown, even within collection events, seemingly unrelated to specimen age. This variation in pubescence color does not warrant further exploration as an indicator of specific differences, but the matter of setae extent is usually more telling. However, few specimens are known from this species’ northernmost limits, and A. albata also varies between banded and unbanded forms (by geography, with exceptions evident in long series). As the bands of A. rhodothorax also appear generally larger with latitude, no taxonomic action is taken here.
Specimens examined: USA: CALIFORNIA: Alameda County: Berkeley: 1 ♀, 10 Sep 1936, collector unknown; Tesla: 1 ♂ 1 ♀, 25 Sep 1948, P.D. Hurd; 2 ♂, 25 Sep 1948, collector unknown; 1 ♀, 15 Oct 1948, P.D. Hurd; 1 ♀, 19 Sep 1950, F. Morishita; Contra Costa County: Antioch: 1 ♂ 3 ♀, 9 Aug 1936, C.D. Michener; 2 ♀, 5 Sep 1936, M. Cazier; 1 ♀, 5 Sep 1936, M.A. Cazier; 1 ♀, 6 Sep 1936, G.E. Bohart; 1 ♂, 9 Sep 1936, E.C. VanDyke; 1 ♀, 10 Sep 1936, M.A. Cazier; 1 ♂, 23 Sep 1936, E.C. VanDyke; 1 ♂ 1 ♂, 18 Sep 1938, E.C. VanDyke; 1 ♀, 23 Oct 1938, J.W. MacSwain; 1 ♀, 11 Sep 1939, M. Cazier; 2 ♀, 17 Sep 1939, collector unknown; 1 ♂, 9 Aug 1947, P.D. Hurd; 1 ♀, 20 Sep 1947, P.D. Hurd; 1 ♀, 24 Sep 1950, J.C. Hall; 1 ♀, 14 Oct 1954, A.M. Barnes; 1 ♀, 14 Oct 1954, M.S. Wasbauer; 2 ♂, 25 Aug 1955, J.G. Rozen; 1 ♂, 5 Sep 1955, P.A. Opler; 1 ♂, 7 Sep 1955, M. Wasbauer; 1 ♂, 1 Sep 1956, P.A. Opler; 1 ♀, 9 Sep 1958, J. R. Powers; 1 ♀, 3 Oct 1958, J. Powell; Antioch, Sand Dunes: 1 ♂, 9 Aug 1947, U.N. Lanham; Oakley: 2 ♂, 22 Aug 1937, E.C. VanDyke; 1 ♂ 1 ♀, 5 Sep 1937, E.C. VanDyke; Fresno County: Hammond Ranch, 5 mi SE Auberry: 2 ♀, 23 Sep 1966, D. Graham; Los Angeles County: Bouquet Canyon: 1 ♂, 23 Aug 1954, R. R. Snelling; Claremont: 2 ♂ 5 ♀, date unknown, Baker; Los Angeles: 1 ♂, date unknown, Coquillett; near Chilao, San Gabriel Mountains, Angeles National Forest: 1 ♂, 15 Sep 1965, R. R. Snelling; Madera County: Nipinnawasee: 1 ♀, 5 Sep 1938, collector unknown; Mendocino County: Ukiah: 2 ♀, 30 Sep 1906, J.C. Bradley; Monterey County: Parkfield: 1 ♂, 16 Sep 1959, R. R. Snelling; Riverside County: 3 mi W of Beaumont: 1 ♂, 16 Sep 1957, collector unknown; El Cariso: 1 ♂, 24 Aug 1983, K.W. Cooper; Idyllwild: 1 ♀, 2 Sep 1959, P. Rude; 1 ♂, 2 Sep 1959, collector unknown; Idyllwild, San Jacinto Mts: 1 ♂ 1 ♀, 12 Aug 1934, C.D. Michener; Riverside: 1 ♂, 8 Sep 1926, P. Timberlake; 1 ♂, 10 Sep 1929, P. Timberlake; 1 ♀, 12 Sep 1929, P.H. Timberlake; 1 ♂, 23 Sep 1929, P.H. Timberlake; 1 ♀, 4 Oct 1929, P. Timberlake; 1 ♀, 10 Oct 1929, P. Timberlake; 1 ♀, 21 Sep 1933, P. Timberlake; San Bernardino County: Colton Sand Hills: 1 ♂ 15 ♀, date unknown, collector unknown; Ontario: 1 ♂, 23 Aug 2001, collector unknown; Rialto: 1 ♂ 1 ♂, 22 Sep 1955, J.C. Hall; San Timoteo Canyon: 1 ♀, 9 Sep 1974, collector unknown; Valley of the Falls: 1 ♂, 4 Aug 1935, P.H. Timberlake; West Colton, SW Corner of Pepper & San Bernardino Avenues: 1 ♂ 1 ♀, 18 Sep 1994, collector unknown; San Diego County: Dodge Valley: 1 ♂ 5 ♀, 1 Sep 1974, H. Nagase; Julian: 1 ♀, 22 Oct 1977, collector unknown; Laguna Mountains: 1 ♀, 1 Oct 1978, collector unknown; Mission Valley: 2 ♀, 11 Sep 1927, J. VonBoeker; Pine Valley: 1 ♂, 12 Sep 1927, collector unknown; San Diego: 1 ♀, 25 Aug 1929, J.
VonBoeker; Warner's: 1 ♀, Sep 1920, collector unknown; San Luis Obispo County: Black Lake Canyon: 1 ♀, 29 Aug 1955, R.K. Washino; Santa Barbara County: Cuyama Ranch, Cuyama Canyon: 1 ♂ 1 ♀, 13 Sep 2013, K.J. Hung; 1 ♂, 22 Aug 2014, K.J. Hung; Siskiyou County: 4 mi NE of Bray: 1 ♀, 24 Aug 1981, T.R. Haig; Sonoma County: Cloverdale: 1 ♂, 21 Aug 1953, E. Schlinger; Stanislaus County: Del Puerto Canyon: 1 ♂, 4 Oct 1956, R.R. Snelling; Trinity County: Junction City: 3 ♂ 1 ♀, 1 Sep 1975, T.R. Haig; 1 ♂, 17 Jun 1977, T.R. Haig; 1 ♂, 18 Sep 1978, T.R. Haig; Tulare County: Mineral King: 1 ♀, 31 Jul 1960, W.E. Simonds; Ventura County: Simi Valley, 8 km ESE: 1 ♀, 13 Sep 2012, collector unknown.
description: Published as part of Orr, Michael C., Pitts, James P. & Griswold, Terry, 2018, Revision of the bee group Anthophora (Micranthophora) (Hymenoptera: Apidae), with notes on potential conservation concerns and a molecular phylogeny of the genus, pp. 1-193 in Zootaxa 4511 (1) on pages 118-121, DOI: 10.11646/zootaxa.4511.1.1, http://zenodo.org/record/3770979