A revision of the simplex species group of the cleptoparasitic bee genus Triepeolus Robertson, 1901 (Hymenoptera: Apidae) Author Onuferko, Thomas M. 6E4CC25A-AD82-42D3-9846-C659EDEAF541 Canadian Museum of Nature, P. O. Box 3443, Station D, Ottawa, ON K 1 P 6 P 4, Canada and University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M 1 C 1 A 4, Canada. thomas.onuferko@gmail.com Author Rightmyer, Molly G. 90A04B61-0B07-4F3F-8F9E-DDCBDC108314 Department of Entomology, San Diego Natural History Museum, 1788 El Prado, San Diego, CA 92101, USA. molly_rightmyer@yahoo.com text European Journal of Taxonomy 2024 2024-09-02 950 1 1 106 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2643/12195 journal article 10.5852/ejt.2024.950.2643 2118-9773 13691805 ACFB8240-3FDC-43B8-8200-236BFE00AD94 Triepeolus mexicanus ( Cresson, 1878 ) Figs 12F , 21 Epeolus mexicanus Cresson, 1878: 90 ( ♀ , ♂ ). Epeolus rugulosus Cockerell, 1917: 299 ( ♂ ), syn. nov. Epeolus metatarsalis Friese, 1921: 91 ( ♂ ), syn. nov. Triepeolus bilunatus Cockerell, 1949: 461 ( ♀ ), syn. nov. Epeolus mexicanus – Cresson 1916: 124 ( ♀ ) ( lectotype designation). Epeolus metatarsalis – Friese 1925: 31 (description of female). Triepeolus mexicanus – Cockerell 1949: 461 . Triepeolus rugulosus – Michener 1954: 128 , figs 86–88. Triepeolus metatarsalis – Moure et al . 2007: 591 . Proposed common name Mexican triepeolus. Diagnosis The following morphological features in combination tell T. mexicanus apart from all other species of Triepeolus : pale tomentum on the mesoscutum is restricted to the lateral and posterior margins ( Fig. 21B ); the T1 basal band is arched, continuous with (and indistinguishable from) the lateral longitudinal bands, and mesally concave on each side, such that the discal patch is semicircular ( Fig. 21B ); and T2–T4 have complete apical transverse bands of yellow tomentum ( Fig. 21B, D ). Triepeolus mexicanus most closely resembles specimens of T. alvarengai without an apical transverse band on T1 and T. nemoralis , both of which are known only from South America, but in T. alvarengai the mesoscutum has well-defined paramedian bands and in T. nemoralis the mesoscutum has a large anteromedial ovate patch of yellow tomentum, which may be sparser medially such that the patch is suggestive of ill-defined paramedian bands. Males of T. mexicanus also closely resemble those of T. flavipennis (Friese, 1916) without an apical transverse band on T1 and T. cameroni (Meade-Waldo, 1913) , but in the latter two species, which are not in the simplex species group, the mesoscutum has well-defined paramedian bands, in T. flavipennis the pair of anterolateral patches of pale tomentum on T1 are mesally convex, such that the discal patch forms a trapezoid or triangle with concave anterolateral sides, and in T. cameroni S3 has an apical/subapical fringe of dense, long (>1 MOD), curved, pale setae (as opposed to only short, straight setae; Fig. 21C ). This species is also very similar in overall appearance to Epeolus luteipennis Friese, 1916 and specimens of E. obscuripes Cockerell, 1917 in which the axillae and mesoscutellum are black, but both sexes of T. mexicanus can easily be told apart from any similar-looking Epeolus by their simple mandibles; in E. luteipennis , E. obscuripes , and most other Epeolus spp. , the mandibles each have a distinct preapical tooth. Etymology The specific epithet refers to the type locality— Mexico . The Latin adjectival suffix ‘-anus’ means ‘of’ or ‘pertaining to’. Material examined Primary type material HONDURAS • ♀ , T. bilunatus holotype ; Francisco Morazán , Zamorano ; 17 Jan. 1947 ; W.P. Cockerell leg.; USNM 534619 . MEXICO • ♀ , E. mexicanus lectotype ; F. Sumichrast leg.; ANSP 2229 . PANAMA • ♂ , E. rugulosus holotype ; Comacho , Canal Zone ; 27 Mar. ; A.H. Jennings leg.; USNM 534866 . Secondary type material MEXICO • 1 ♂ , E. mexicanus lectoallotype ; F. Sumichrast leg.; ANSP 2229-2 • 2 ♀♀ , E. mexicanus paralectotypes ; F. Sumichrast leg.; ANSP 2229-6 , 2229-9 • 1 ♀ , E. mexicanus paralectotype ; USNM 2229.5 /M.G.R. Database No. 5851 . DNA barcoded material Available. BIN: BOLD:AAV3172. Specimens examined and sequenced: MEXICO • 1 ♀ ; Jalisco , Chamela Eje Central trail; 19.5001° N , 105.0427° W ; 1 Oct. 2010 ; S. Dumesh leg.; BOLD sample ID: CCDB-09669 A11; PCYU PCYU-MEX10-0013 . USA – Arizona • 1 ♂ ; Community Road , Cochise County ; 32.0137° N , 109.0873° W ; 26 Aug. 2011 ; N. de Silva leg.; BOLD sample ID: 14511H03-NM ; PCYU 0003812 . – New Mexico • 1 ♂ ; NW of Lordsburg , Hidalgo County ; 32.5507° N , 108.9226° W ; 3 Sep. 2015 ; L. Packer leg.; BOLD sample ID: CCDB-30344 C11 ; PCYU . Non-barcoded material COSTA RICA – Alajuela • 1 ♀ (supposedly an E. metatarsalis syntype , but the designation is suspect as Friese 1921 only described the male); San Mateo ; May 1921 ; AMNH AMNH _ IZC 00324050 . – Guanacaste • 1 ♀ ; 5 mi NW of Las Cañas ; 26 Jun. 1963 ; Wille and Michener et al . leg.; KUNHM M.G.R. Database No. 5068 • 1 ♀ ; Guanacaste National Park ( Maritza Biological Station ); “ I/12/1995 ”; L.S. Kimsey leg.; UCBME • 1 ♀ ; Hacienda Comelco ( 24 km NW of Canas on Inter-American Hwy ); 5 Aug. 1971 ; E.R. Heithaus leg.; LACM 5339 , coll. #282/M.G.R. Database No. 3422 • 1 ♂ ; Palo Verde Biological Station ; 10.3475° N , 85.3497° W ; 17 Nov. 2001 ; R.W. Brooks leg.; KUNHM CR1B01 31 /M.G.R. Database No. 5071 • 1 ♂ ; Palo Verde Biological Station ; 10.3968° N , 85.3236° W ; 18 Nov. 2001 ; R.W. Brooks leg.; KUNHM CR1B01 42 /M.G.R. Database No. 5070 . GUATEMALA • 1 ♀ ; El Progreso , Puente El Hato ( 49.9 mi NE of Guatemala City ); 5 Aug. 1966 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 5067 . HONDURAS – Francisco Morazán • 1 ♀ ; Zamorano ; 20 Jan. ; USNM M.G.R. Database No. 6221 • 1 ♀ ; same data as for preceding; 24 Jan. ; USNM M.G.R. Database No. 6217 • 2 ♀♀ ; same data as for preceding; 26 Jan. ; USNM M.G.R. Database Nos 6220 , 6222 • 1 ♀ ; same data as for preceding; 26 Jan. ; F. Wiley leg.; USNM M.G.R. Database No. 6219 • 3 ♀♀ ; same data as for preceding; 30 Jan. ; USNM M.G.R. Database Nos 6215 , 6216 , 6218 . Fig. 21. Triepeolus mexicanus ( Cresson, 1878 ) . A–B , D . Female (BOLD sample ID: CCDB-09669 A11; PCYU PCYU-MEX10-0013). A . Habitus, lateral view. B . Habitus, dorsal view. C . Male (BOLD sample ID: CCDB-30344 C11; PCYU), habitus, lateral view. D . Pseudopygidial area, dorsal view. MEXICO – Chiapas • 1 ♀ ; Nututun ( 3 km S of Palenque ); 25 Apr. 1993 ; J.L. Neff leg.; KUNHM SM0326531 /M.G.R. Database No. 7134 • 1 ♀ ; same data as for preceding; 25 Apr. 1993 ; R. Brooks leg.; KUNHM SM0326533 /M.G.R. Database No. 7139 • 1 ♀ ; same data as for preceding; 25 Apr. 1993 ; R. Brooks leg.; KUNHM SM0326534 /M.G.R. Database No. 7137 . – Jalisco • 1 ♂ ; Chamela ; 26 Sep. 1985 ; R.J. McGinley leg.; USNM M.G.R. Database No. 6226 • 2 ♂♂ ; same data as for preceding; 27 Sep. 1985 ; R.J. McGinley leg.; KUNHM M.G.R. Database Nos 5058 , 5059 • 1 ♀ ; same data as for preceding; 1–8 Oct. 1985 ; F.D. Parker and T.L. Griswold leg.; KUNHM M.G.R. Database No. 5056 • 1 ♀ ; same data as for preceding; 10 Dec. 1989 ; “ Rodriguez G. ” leg.; UNAM M.G.R. Database No. 1553 • 1 ♀ ; Estación de Biología , Chamela ; 11 Jul. 1989 ; R. Brooks , C. Michener , and A. Roig-Alsina leg.; KUNHM #015 /M.G.R. Database No. 5057 . – Morelos • 1 ♀ ; 11 mi S of Tlaltizapán ; 16 Aug. 1962 ; Roberts and Marston leg.; KUNHM M.G.R. Database No. 5062 . – Nayarit • 1 ♀ ; San Blas ; 7 Apr. 1994 ; R. Ayala leg.; KUNHM PCAM5-9 010/M.G.R. Database No. 5054 • 1 ♀ ; same data as for preceding; 7 Apr. 1994 ; R. Ayala leg.; KUNHM PCAM5-9 010 /M.G.R. Database No. 5055 . – Oaxaca • 1 ♀ ; 12 mi W of Tehuantepec ; 16 Sep. 1974 ; G. Bohart and W. Hanson leg.; AMNH M.G.R. Database No. 2353 • 1 ♂ ; same data as for preceding; 16 Sep. 1974 ; G. Bohart and W. Hanson leg.; AMNH M.G.R. Database No. 2355 • 1 ♀ ; same data as for preceding; 16 Sep. 1974 ; G. Bohart and W. Hanson leg.; KUNHM M.G.R. Database No. 3893 • 1 ♂ ; same data as for preceding; 16 Sep. 1974 ; G. Bohart and W. Hanson leg.; KUNHM M.G.R. Database No. 3894 • 1 ♀ ; same data as for preceding; 16 Sep. 1974 ; G. Bohart and W. Hanson leg.; LACM M.G.R. Database No. 3421 • 1 ♂ ; same data as for preceding; 16 Sep. 1974 ; G. Bohart and W. Hanson leg.; LACM M.G.R. Database No. 3425 • 1 ♀ ; 4 mi E of Tapanatepec ; 9 Jul. 1953 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 5063 • 1 ♀ ; 6 mi S of Tehuantepec ; 8 Jul. 1953 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 1324 • 1 ♂ ; 8 km W of Tehuantepec ; 9–10 Aug. 1974 ; E.M. and J.L. Fisher leg.; LACM M.G.R. Database No. 3428 • 1 ♀ ; Salina Cruz ; 8 Jul. 1953 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 5064 • 1 ♂ ; Tequisistlán ; 7 Jan. 1948 ; T. MacDougal leg.; AMNH M.G.R. Database No. 1491 • 1 ♀ ; San Luis Potosí , 15 mi S of Pujal ; 21 Jun. 1953 ; Univ. Kans. Mex. Expedition leg.; UCBME • 1 ♂ ; same data as for preceding; 21 Jun. 1953 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 5053 . – San Luis Potosí • 1 ♀ ; 3 mi E of Cascada el Salto ; 21 Jul. 1962 ; Ordway and Roberts leg.; KUNHM M.G.R. Database No. 5051 • 7 ♀♀ ; Cascada el Salto ; 3–5 Jul. 1990 ; R.L. Minckley leg.; KUNHM M.G.R. Database Nos 5042 to 5048 • 1 ♀ ; same data as for preceding; 4 Jul. 1990 ; I. Yarom leg.; KUNHM M.G.R. Database No. 5049 • 1 ♀ ; Cascada el Salto ( 12 km NW of El Naranjo ); 3 Jul. 1990 ; D. Yanega leg.; UCR UCRC ENT 57102/M.G.R. Database No. 1554 • 1 ♂ ; El Salto ; 8 Jun. 1961 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 5050 • 1 ♀ ; same data as for preceding; 4 Sep. 1962 ; Ordway and Marston leg.; KUNHM M.G.R. Database No. 5052 • 1 ♂ ; Tamazunchale ; 1 May 1976 ; E. Barrera leg.; LACM M.G.R. Database No. 3427 . – Sinaloa • 1 ♂ ; 20 mi N of Los Mochis ; 9 Oct. 1968 ; G.E. Bohart leg.; CAS M.G.R. Database No. 11712 • 7 ♂♂ ; 5 mi N of Mazatlán ; 5–7 Aug. 1964 ; J.E.H. Martin leg.; CNC 754101 to 754103 , 754115 to 754117 • 1 ♀ ; 7 mi S of Culiacán ; 23 Aug. 1960 ; R.L. Westcott leg.; LACM M.G.R. Database No. 3424 • 1 ♂ ; same data as for preceding; 23 Aug. 1960 ; R.L. Westcott leg.; LACM M.G.R. Database No. 3429 • 9 ♂♂ ; Mazatlán ; 6 Aug. 1964 ; W.R.M. Mason leg.; CNC 754104 to 754108 , 754112 to 754114 , 754087 • 3 ♂♂ ; same data as for preceding; 16 Aug. 1964 ; J.F. McAlpine leg.; CNC 754109 to 754111 . – Sonora • 2 ♀♀ ; 108 km W of Hermosillo ; 16 Aug. 1991 ; R.L. Minckley leg.; KUNHM M.G.R. Database Nos 5040 , 5041 • 1 ♀ ; 13 km W of Álamos ; 1 Sep. 1975 ; B. Villegas leg.; UCBME • 1 ♂ ; Álamos ; 3 Sep. 1991 ; J.G. Rozen leg.; KUNHM SM0326519 /M.G.R. Database No. 7136 • 1 ♂ ; same data as for preceding; 3 Sep. 1991 ; J.G. Rozen leg.; KUNHM SM0326523 /M.G.R. Database No. 7138 • 1 ♀ ; same data as for preceding; 4 Sep. 1991 ; J.L. Neff leg.; KUNHM SM0326524 /M.G.R. Database No. 7135 • 1 ♂ ; Microondas Road ( 19 km N of Hwy 15 and Hwy 24 junction); 20 Mar. 1990 ; R.L. Minckley leg.; KUNHM M.G.R. Database No. 5069 • 1 ♀ ; San Bernardo ; 16 Aug. 1935 ; H.S. Gentry leg.; LACM acc. 1031/M.G.R. Database No. 3423 • 1 ♂ ; same data as for preceding; 16 Aug. 1935 ; H.S. Gentry leg.; LACM acc. 1031/M.G.R. Database No. 3426 . – Tamaulipas • 1 ♂ ; 14 mi S of Antiguo Morelos ; 21 Jul. 1954 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 5060 • 1 ♀ ; 22 mi S of Jiménez ; 15 Jun. 1953 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 5065 • 1 ♀ ; 6.6 mi W of Antiguo Morelos ; 3 Sep. 1962 ; Ordway and Naumann leg.; KUNHM M.G.R. Database No. 5061 • 1 ♀ ; El Limón ; 17 Jun. 1953 ; Univ. Kans. Mex. Expedition leg.; KUNHM M.G.R. Database No. 5066 . – Veracruz • 1 ♀ ; Rancho El Bejuco , Ozuluama ; 3–4 Oct. 1985 ; G. Ekls leg.; UCBME . NICARAGUA • 1 ♀ ; Chinandega , Chinandega ; Baker leg.; USNM 2400 /M.G.R. Database No. 6223 . PANAMA – Coclé • 1 ♂ ; El Valle de Antón ; 1 Apr. 1945 ; C.D. Michener leg.; KUNHM M.G.R. Database No. 1515 . – Panamá • 1 ♂ ; Ancon Hill (Panama City); 20 Dec. 1944 ; C.D. Michener leg.; KUNHM M.G.R. Database No. 3897 • 1 ♂ ; Balboa ; T. Hallinan leg.; AMNH M.G.R. Database No. 2354 • 1 ♂ ; Culebra ; 22 Nov. 1914 ; T. Hallinan leg.; AMNH M.G.R. Database No. 3273 . USA – Arizona • 2 ♂♂ ; 2.5 mi NW of Salome , La Paz County ; 17 Aug. 1969 ; P.D. Hurd leg.; USNM M.G.R. Database Nos 6224 , 6225 • 1 ♀ ; 9 mi NE of Portal , Cochise County ; 18 Aug. 1992 ; J.G. Rozen leg.; AMNH M.G.R. Database No. 2323 • 4 ♂♂ ; Cibola area ( 8 mi S of Ehrenberg ), La Paz County ; 9 Aug. 2000 ; N.J. Smith and A.J. Gilbert leg.; UCBME • 1 ♀ ; Sabino Canyon , Pima County ; 25 Jun. 1963 ; F.D. Parker leg.; UCBME • 1 ♀ ; San Simon , Cochise County ; 4 Sep. 1989 ; J.G. and B.L. Rozen and R. Foster leg.; AMNH M.G.R. Database No. 2324 • 1 ♂ ; Southwestern Research Station ( 5 mi W of Portal ), Cochise County ; 4 Jul. 1959 ; M. Statham leg.; AMNH M.G.R. Database No. 2325 . Non-preserved material BELIZE • 1 ♀ ; Orange Walk District ; 6 May 2023 ; S. Werle obs.; iNaturalist record #162023522 . MEXICO – Chihuahua • 1 ♀ ; Julimes ; 28.3916° N , 105.4578° W ; 11 Jul. 2021 ; “ juanloredo ” obs.; iNaturalist record #86701761 • 1 ♀ ; Meoqui ; 28.2597° N , 105.4956° W ; 23 Sep. 2023 ; L. Hernández Escudero obs.; iNaturalist record #184679437 • 1 ♀ ; Meoqui ; 28.2609° N , 105.4924° W ; 28 Jul. 2023 ; L. Hernández Escudero obs.; iNaturalist record #175704384 • 1 ♀ ; Meoqui ; 28.2622° N , 105.4955° W ; 24 Jun. 2022 ; L. Hernández Escudero obs.; iNaturalist record #123403283 • 1 ♀ ; Meoqui ; 28.2623° N , 105.4953° W ; 24 Jun. 2022 ; L. Hernández Escudero obs.; iNaturalist record #123403281 • 1 ♀ ; Meoqui ; 28.2624° N , 105.4929° W ; 27 Jul. 2022 ; L. Hernández Escudero obs.; iNaturalist record #128379212 • 1 ♂ ; Meoqui ; 28.2638° N , 105.4715° W ; 9 Aug. 2021 ; “ juanloredo ” obs.; iNaturalist record #90605169 • 1 ♂ ; Meoqui ; 28.2924° N , 105.4475° W ; 6 Jul. 2023 ; L. Hernández Escudero obs.; iNaturalist record #171658341 • 1 ♂ ; Meoqui ; 28.2630° N , 105.4938° W ; 6 Oct. 2023 ; L. Hernández Escudero obs.; iNaturalist record #186525973 . – Oaxaca • 1 ♂ ; 4ta, 70110 Ixtepec ; 16.5696° N , 95.0983° W ; 17 Nov. 2022 ; “ MarCheläs ” obs.; iNaturalist record #142539748 • 1 ♀ ; Ixtepec ; 16.5697° N , 95.0980° W ; 5 May 2023 ; “ MarCheläs ” obs.; iNaturalist record #159965832 • 1 ♂ ; Ixtepec ; 16.5697° N , 95.0983° W ; 14 Nov. 2023 ; “ MarCheläs ” obs.; iNaturalist record #191026657 • 1 ♂ ; same data as for preceding; 21 Nov. 2023 ; “ MarCheläs ” obs.; iNaturalist record #191722826 . – Sonora • 1 ♀ ; San José de Bácum ; 27.5179° N , 110.1369° W ; 24 Sep. 2022 ; K. Reynaga obs.; iNaturalist record #144652014 . NICARAGUA • 1 ♀ ; Masaya , Las Flores ; 15 Jun. 1994 ; J.M. Maes obs.; iNaturalist record #177727568 . USA – Arizona • 1 ♀ ; Arizona-Sonora Desert Museum ( Tucson ), Pima County ; 25 Jul. 2018 ; P. Murray obs.; BugGuide record # 1570812 • 1 ♂ ; Arizona-Sonora Desert Museum ( Tucson ), Pima County ; 32.2427° N , 111.1673° W ; 3 Oct. 2021 ; T. Palmer obs.; iNaturalist record #97093457 • 1 ♀ ; Dankworth Pond ( S of Safford ), Graham County ; 27Aug. 2008 ; D. Danforth leg.; BugGuide record # 466015 / 466016 • 1 ♀ ; Las Vistas , Avondale , Maricopa County ; 33.4819° N , 112.3034° W ; 28 Sep. 2021 ; Kneubauer obs.; iNaturalist record #96546894 • 1 ♀ ; Saguaro National Park East , Pima County ; 20 Aug. 2022 ; D. Sandri obs.; iNaturalist record #135607905 . Redescription MEASUREMENTS OF LECTOTYPE . Body length 10.8 mm ; ITW 2.1 mm ; head length 2.5 mm ; head width 3.5 mm ; fore wing length 7.8 mm . Both sexes INTEGUMENT COLORATION . Dark brown to black except as follows. Mandible with middle quarter in basal half reddish brown. Scape to some extent (entirely dark brown/black in some non-type specimens), pedicel and F1 extensively, and tegula orange. F2 with orange spot basally. Fore wing membrane dusky subhyaline throughout. Hind wing membrane dusky subhyaline to hyaline. Legs to some extent orange in E. mexicanus lectotype , possibly due to discoloration/fading, T. bilunatus holotype , and some non-type specimens. Pygidial plate reddish brown. PUBESCENCE . Face with tomentum densest around antennal socket. Tomentum slightly sparser on clypeus; upper paraocular and frontal areas and vertexal area mostly exposed. Pronotal collar with tomentum uniformly bright yellow. Mesoscutum with pale (yellow) tomentum restricted to lateral and posterior margins. Mesopleuron with off-white, 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 black medially. Propodeal triangle mostly glabrous, with (pale) setae restricted to small lateral patches. T1 with basal transverse band of bright yellow tomentum separated medially into pair of anterolateral patches (complete in some non-type specimens), continuous with (and indistinguishable from) lateral longitudinal band, forming arch around semicircular discal patch. T2–T4 with complete apical transverse bands of bright yellow tomentum without well-defined anterolateral extensions, although T2–T3 with faint lateral longitudinal bands of diffuse off-white setae. S2–S3 with apical transverse bands of white tomentum. SURFACE SCULPTURE . Labrum, clypeus, mesoscutum, mesoscutellum, and axilla with punctures equally dense and nearly contiguous (most i<1d). Vertexal area somewhat sparsely punctate (some i>2d) anteriorly and around ocelli, otherwise densely (most i <1d) rugose-punctate. Mesopleuron with punctures in upper half denser (most i ≤ 1d) than in ventrolateral half (i≤ 3d); interspaces shining; punctures similar in size throughout. Discs of metasomal terga with punctures very fine, dense (i≈ 1d), and evenly distributed; interspaces somewhat dull due to tessellate surface microsculpture. STRUCTURE . Labrum with pair of small subapical denticles, each preceded by discrete longitudinal ridge. Pronotal collar somewhat elongate (medial length ~ 3/5 MOD). Mesoscutellum moderately bigibbous. Axilla extending little if at all beyond midlength of mesoscutellum; tip distinctly pointed, but mesally unattached to mesoscutellum for less than 2/5 medial length of axilla; lateral margin somewhat sinuate. Fore wing with three submarginal cells. Female T5 with concave apical margin and large patch of pale-yellow tomentum on each side lateral to pseudopygidial area. Pseudopygidial area forming rounded triangle with concave sides. Pygidial plate apically truncate. S4 with apical transverse band of white tomentum. S5 straight in lateral view, with apical fimbria of coppery bristle-like setae. Male T5–T6 with complete apical transverse bands of bright yellow tomentum. Pygidial plate relatively flat and apically rounded. S4–S5 each with apical/subapical fringe of dense, long (> 1 MOD), curved, coppery setae, contrasting with apical transverse bands of white tomentum of preceding sterna. Distribution Southwestern United States to Panama ( Fig. 12F ). Ecology Host records Unknown. Floral records 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 , Baltimora sp. , Bidens pilosa L., Gaillardia pulchella , Helenium sp. , Melanthera nivea (L.) Small, Tridax procumbens L., and Verbesina sp. ; in Boraginaceae , Heliotropium sp. and H. curassavicum L.; in Convolvulaceae Juss. , Ipomoea sp. ; in Euphorbiaceae , Euphorbia sp. ; in Fabaceae , Medicago sp. , Mimosa sp. , and Prosopis juliflora (Sw.) DC. ; in Lamiaceae , Hyptis suaveolens (L.) Poit.; in Malvaceae , Anoda cristata (L.) Schltdl., Gossypium sp. , and Sphaeralcea angustifolia G.Don ; in Salicaceae Mirb. , Salix sp. ; in Tamaricaceae , Tamarix chinensis Lour. ; in Verbenaceae J.St. -Hil., Lippia sp. or spp.; and in Zygophyllaceae , Kallstroemia grandiflora . Remarks In the original description of E. rugulosus , Cockerell (1917) did not mention E. mexicanus and described the holotype of the former as being “somewhat related to E. xanthurus ” Cockerell, 1917 , a name that has since been synonymized under E. luteipennis (Onuferko 2019) . The (male) holotype of E. rugulosus was examined and agrees with the diagnosis for T. mexicanus provided herein. Friese (1921) described E. metatarsalis from an unspecified number of male specimens. The whereabouts of any syntypes are unknown, despite searches by the second author through the ZMB where most of Heinrich Friese’s type material has been deposited. Although the AMNH has a specimen labeled as E. metatarsalis that bears an orange label that says “Typus”, it is female, and the collection date ( May 1921 ) does not match that given in the original description (July), so the specimen does not belong to the original type series. In the original description, Friese (1921) did not mention E. mexicanus and compared E. metatarsalis only to E. flavocinctus Friese, 1916 , a name that has since been synonymized under T. aztecus ( Cresson, 1878 ) ( Rightmyer 2008 ) . However, the male was described as having yellow pubescence along the margins of the mesoscutum (with no mention of any paramedian bands or pale pubescence medially), a pair of patches of yellow tomentum basally on T1, and bands of yellow tomentum on the succeeding terga, features that in combination are diagnostic for T. mexicanus . Cockerell (1949) described T. bilunatus from a single (female) specimen and described it as closely resembling T. mexicanus , to which he “was almost ready to refer this [specimen]” but did not on the basis that in T. mexicanus the sides of the metathorax are covered with dense yellowish pubescence. Both the holotype of T. bilunatus and lectotype of E. mexicanus were examined in the present study, and the posterior part of the mesosoma is not more noticeably densely or yellow pubescent in the latter than in the former. As there are no discernable morphological differences among the primary types of E. mexicanus , E. rugulosus , and T. bilunatus and the description of E. metatarsalis closely describes the lectotype of E. mexicanus , apart from sex-specific differences, E. rugulosus , E. metatarsalis , and T. bilunatus are herein synonymized under T. mexicanus . A female paralectotype of E. mexicanus (ANSP 2229-8), which has been incorrectly designated and labeled as a “Para-Type”, is not the same species as the lectotype but rather T. flavipennis , a similar-looking species in the T. verbesinae group.