JHR 95: 275-293 (2023) Agee Se,” JOURNAL OR See wntemicstiante doi: 10.3897/jhr.95.96025 RESEARCH ARTICLE () Hymenopter a Q https://jhr.pensoft.net Te Inarasional Society of Hymenopeeriss, RESEARCH The North American bees of the genus Ptilothrix Cresson, 1878 (Hymenoptera, Apidae, Emphorini), with the description of two new species Nathalia Flérez-Gémez', Bryan Danforth! | Department of Entomology, Cornell University, Ithaca, New York 14853, USA Corresponding author: Nathalia Flérez-Gémez (naf63@cornell.edu) Academic editor: Jack Neff | Received 6 October 2022 | Accepted 15 February 2023 | Published 24 February 2023 https://zoobank. org/55 CBO5E0-743C-4CDB-BD29-3D 1 14676F090 Citation: Flérez-Gémez N, Danforth B (2023) The North American bees of the genus Ptilothrix Cresson, 1878 (Hymenoptera, Apidae, Emphorini), with the description of two new species. Journal of Hymenoptera Research 95: 275-293. https://doi.org/10.3897/jhr.95.96025 Abstract Ptilothrix Cresson is a genus of New World bees with an amphitropical distribution. Like other genera in the tribe Emphorini, Ptilothrix have narrow pollen preferences. These solitary ground-nesting bees exhibit a remarkable nesting behavior in which females carry water from ponds to facilitate the excavation of the hard soil where they nest. With 16 described species, there are few taxonomic studies and, before this work, a lack of taxonomic treatments for the species in North America. Thus, in this study we revised and recognized four species for the region: Ptilothrix bombiformis Cresson, Ptilothrix sumichrasti Cres- son, Ptilothrix chiricahua Florez-Gomez & Danforth, sp. nov. and Ptilothrix zacateca Florez-Gomez & Danforth, sp. nov. We describe and illustrate males and females of the two new species. We also present diagnoses for the four species, a key to identify them, and a map of their geographic distributions. Keywords Anthophila, Apoidea, Chiricahua, Mexico, taxonomy Introduction The genus Prilothrix Cresson, 1878 is a group of bees restricted to the Western hemi- sphere with an amphitropical distribution. In North America the genus is found from Ontario, Canada to Oaxaca, Mexico and in South America it occurs from northern Copyright Nathalia Flérez-Gomez & Bryan Danforth. This is an open access article distributed under the terms of the Creative Commons At- tribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 27 WNathalia Flérez-Gomez & Bryan Danforth / Journal of Hymenoptera Research 95: 275-293 (2023) Brazil to northern Patagonia, Argentina (Michener 2007; Roig-Alsina 2007; Sharkey et al. 2020). Like many members in Emphorini, species in this genus are pollen specialists that are associated with plants in the families Malvaceae, Cactaceae, Convolvulaceae, Zygophyllaceae and Onagraceae (Cazier and Linsley 1974; Rust 1980; Hazeldine 1997; Telleria 2003; Sipes and Tepedino 2005). Ptilothrix species are solitary bees that nest in aggregations in flat or slightly sloping areas of hardpacked sandy soil that is softened with water they collect by alighting on nearby bodies of water (Linsley et al. 1956; Martins et al. 1996; Michener 2007). Within Emphorini, Ptilothrix is phylogenetically related to Diadasina and Melitomella (Roig-Alsina and Michener 1993; Freitas et al. 2020), both South Ameri- can genera. Morphologically, the genus can be distinguished from the other genera in the tribe by the lack of arolia, elongated first flagellomere, tongue not surpassing the forecoxae, upper margin of the clypeus surpassing the lower margin of the antennal sockets, and widely spaced tibial scopal hairs with straight branches (Roig-Alsina 1998; Michener 2007; Roig-Alsina 2007). The genus currently includes 16 described species (Ascher and Pickering 2020), 14 of which are in South America. Taxonomic studies are scarce, the only previous revi- sion is by Roig—Alsina (2007) for the albidohirta group, which comprises three species that are known for Bolivia and Argentina. In North America there are three reported species: P bombiformis Cresson, P sumichrasti Cresson and one undescribed species that has been identified in bee surveys as P nr. sumichrasti (Michener 2007; Minckley and Radke 2021). Herein we describe this species and one new species from Mexico, we also present diagnosis of the North American species, an identification key to rec- ognize males and females, and a map of their geographic distribution. Methods We examined specimens deposited in the following collections: Cornell University Insect Collection (CUIC), American Museum of Natural History (AMNH), Snow Entomological Museum, University of Kansas (SEM), USDA-ARS Pollinating Insects Research Unit, Utah State University (BBSL), Central Texas Melittological Institute (CTMI), Texas A8&¢M University (TAMU), Minckley collection at the University of Rochester (MCUR), Illinois Natural History Survey Insect Collection (INHS), Ento- mology Research Museum at UC Riverside (UCRC) and Coleccién Nacional de Insec- tos, Departamento de Zoologia, Instituto de Biologia UNAM, Mexico (CNIN). Ad- ditionally, we examined the lectotypes of P sumichrasti and P bombiformis obtained on loan from the Academy of Natural Sciences of Drexel University (ANSP). Designated holotypes and paratypes were deposited at CUIC, AMNH, SEM, CTMI and BBSL. The morphological terminology used in this study follows that proposed by Michener (2007). Abbreviations in the descriptions and key are T, S, and MOD for metasomal terga, metasomal sterna and median ocellar diameter, respectively. We made the descriptions based on holotype and paratype specimens, measurements were made using a Zeiss Stemi SV11 microscope and are expressed in millimeters (mm). The North American species of the genus Ptilothrix DT7. Additionally, we dissected male genitalia, seventh and eighth sterna (S7 and S8), these structures were cleared using a 10% NaOH solution and stored in glycerin. We took habitus images with a Cannon EOS 6D and a 65 mm macro lens. To stack single photographs we used a Stackshot 3x Cognisys device and Zerene stack software. Pho- tographs of other structures were taken using a Zeiss Stemi SV6 microscope with an Axiocam 105 color camera. Finally, the known distribution obtained from the specimen labels of the four species were mapped using QGIS software and topographic layers downloaded from EarthEnvy. For Prilothrix bombiformis, we additionally included data from the Global Biodiversity Information Facility (GBIF). Results Genus Ptilothrix Smith, 1853 Ptilothrix chiricahua sp. nov. https://zoobank.org/9687 1ED3-1B4A-48BD-87 14-00BC4B91D5B9 Figs 1, 2A, B, 3A, B, 4B, 5 Diagnosis. Body size of females from 8.6—12 mm, males 9-10.8 mm. This species is distinguished by the polished and shiny ocellocular area, with few scattered punctures close to the eye margin in both sexes. Morphologically similar to P sumichrasti, but males differ by the yellowish pubescence on T’7, and the shape of S7, S8 and the genital capsule (Figs 2A, B, 3A, B). As in P sumichrasti, this species is characterized by the rela- tively short first flagellomere (when compared with other Ptilothrix), length no more than twice its apical width; fulvous pubescence on pronotum, scutum, scutellum, pale yellowish to white in some specimens, and whitish on the mesepisternum and propo- deum. Metasoma with apical bands of yellowish appressed hairs on T1—T4. Anterior area of [3-15 with black, short appressed hairs. Description. Male. Total length 9.16 mm (paratypes 9-10.8 mm, n=10). Head. Integument black, except mandible brown with middle area lighter brown; apex yel- lowish in some paratypes. Mandible with rounded apical margin. Pubescence whitish on labrum, clypeus, around antennal sockets, frons and gena, becoming pale yellow- ish on vertex, whitish in some paratypes. Labrum rectangular, disc densely punctate, margin raised and impunctate. Clypeus protuberant in lateral view, with punctures densely distributed, separated by a distance less than a puncture diameter. Punctation of lower paraocular area, supraclypeal area and frons punctation as in clypeus. Inner ocular margins subparallel. Ocellocular area polished, with few scattered punctures and short pilosity closer to the eye margin, distance 0.52 mm. Antennae dark brown, scape 0.68 mm long, first flagellomere longer than broad, 1.7 times longer than its api- cal width. Head length 2.6 mm. Head width 3.2 mm. Gena width 0.62 mm. Lower interocular distance 1.8 mm. Upper interocular distance 2 mm. Lower interocular distance 0.8 mm. Antennocular distance 0.28 mm. MOD 0.228 mm. 27 Nathalia Flérez-Gomez & Bryan Danforth / Journal of Hymenoptera Research 95: 275-293 (2023) Mesosoma. \ntegument black. Pubescence fulvous on the pronotum, scutum, scutellum and metanotum; becoming whitish towards the propodeum, mesepister- num and metepisternum; some paratypes with pubescence entirely whitish. Propodeal triangle with short appressed, whitish hairs. Scutum with homogeneously distributed punctures separated by a distance up to a puncture diameter. Mesepisternal disc with punctures densely distributed, separated by a distance up to a puncture diameter, in- terspaces shiny. Hypoepimeral area with close punctures on the upper area, impunctate and polished towards the scrobal groove. Tegula translucent brownish. Tuft of yellow pubescence at base of wings, membrane of wings subhyaline, venation brown. Length of forewing 8 mm. Intertegular distance 2.6 mm. Scutum length 2.35 mm. Legs. Integument dark brown, except tarsi reddish brown, with whitish pubescence. Hind coxa and femur enlarged. Hind basitarsus slightly curved, 5 times the length of the second tarsomere. Posterior tibial spurs slightly hooked at the apex. Metasoma. Tergal integument black, sterna brown. T1 and T2 covered with whit- ish erect pilosity and posterior margin with a band of yellowish appressed hairs. T3—T6 with appressed short, dark hairs, margin with bands of yellowish pilosity. T7 covered with yellowish pubescence, apical margin with two pointed projections forming a me- dial U-shaped notch. Sternal pubescence erect, yellowish. S6 with a median tuft of hairs. Metasomal pubescence whitish in some paratypes. S7 and S8 as in Fig. 2A, B. Gonobase rounded, middle area of gonostylus slightly broadened (Fig. 3A, B). Female. Total length 10.62 mm (8.6-12 mm n=10). Head. Integument color as in males. Maxillary palpus 6-segmented, segments 1—4 with short setae on the outer margin. Mandible with rounded apical margin. Pubescence color as in males, but hairs shorter. Labrum densely punctate, apex subtriangular with margin raised, impunctate. Inner ocular margins nearly parallel. Clypeus as in male, interspaces between punctures up to a puncture diameter. Punctation in paraocular area as in males. Ocellocular area polished and with few scattered punctures and short pilosity closer to the eye mar- gin, distance 0.56 mm. Antennae dark brown, scape 0.71 mm long, first flagellomere 1.8 times longer than its apical width (Fig. 4B). Head length 2.7 mm. Head width 3.45 mm. Gena width 0.44 mm. Lower interocular distance 2.02 mm. Upper interocu- lar distance 2.2 mm. Interocular distance 0.98 mm. Antennocular distance 0.3 mm. MOD 0.25 mm. Mesosoma. Color, punctures and pubescence color as in males, but hairs shorter. Wings and tegula as in males. Length of forewing 8.5 mm. Intertegular distance 2.66 mm. Scutum length 2.56 mm. Legs. Integument and pubescence color as in male. Hind tibia with whitish scopa, apical margin with a tuft of white pubescence, inner surface rugose and with short and appressed hairs. Scopa on hind basitarsus whit- ish on the outer surface and brownish on the inner surface. Metasoma. Integument as in male. T1—T'4 pubescence as in male. T'5 with black, short and appressed hairs on the an- terior area, prepygidial fimbria yellowish with brown hairs intercalated, entirely brown in some paratypes. Pygidial fimbria dark brown. Pygidial plate with rounded apex. Material examined. Holotype. UNrTED STATES OF AMERICA ® S; New Mexico; Hidalgo Co.1 mi. S Rodeo; 23 Aug. 2002; B.N. Danforth leg.; on Kallstroemia; CUIC. Paratypes. Mexico — Sonora * 1 9; Rancho San Bernardino. 28 km E Agua Prie- ta, Ciénaga; 27 Jul. 2000; K. Toal leg; MCUR 1519 © 1 2; same data as for preceding; The North American species of the genus Ptilothrix 279 Figure |. Ptilothrix chiricahua sp. nov. A male holotype habitus, lateral view B male holotype habitus; frontal view C male holotype dorsal view D male holotype metasoma E female paratype habitus, lateral view F female paratype habitus, frontal view G female paratype dorsal view H female paratype metasoma. 22 Jun. 2000; MCUR 1874 « 1 3S; 30 km E Agua Prieta; 31°19'08"N, 109°15'04"W; 12 Aug 2001; A. Romero leg., MCUR SBV043745. Unitep States of America — Arizona * 1 3; Cochise Co. 10 mi SW Apache; 31.571°N, 109.26°W; 27 Aug. 2014; B.N. Danforth leg.; CUIC © 5 9, 44; Cochise 28(Nathalia Flérez-Gémez & Bryan Danforth / Journal of Hymenoptera Research 95: 275-293 (2023) Mh Mm aa Z) e & £3 Figure 2. A Ptilothrix chiricahua sp. nov. male S7 B Ptilothrix chiricahua sp. nov. male $8 € Ptilothrix za- cateca sp. nov. male S7 D Prilothrix zacateca sp. nov. male S8 E Ptilothrix sumichrasti male S7 F Prilothrix sumichrasti male $8 G Ptilothrix bombiformis male S7 H Ptilothrix bombiformis male S8. The North American species of the genus Ptilothrix 281 A B 50 um C D E F A 50 um 50 ym G H 50pm {ee Figure 3. A, B Ptilothrix chiricahua sp. nov. male genital capsule A dorsal view B ventral view C, D Prilothrix zacateca sp. nov. male genital capsule C dorsal view D ventral view E, F Ptilothrix sumi- chrasti male genital capsule E dorsal view F ventral view G, H Prilothrix bombiformis male genital capsule G dorsa view F ventral view. 28 Nathalia Flérez-Gomez & Bryan Danforth / Journal of Hymenoptera Research 95: 275-293 (2023) Figure 4. Ocellocular area and antenna of A female lectotype of Ptilothrix sumichrasti B female paratype of Ptilothrix chiricahua sp. nov. C female paratype of Ptilothrix zacateca sp. nov. Co. Portal 6 mi E; 31.876°N, 109.058°W; 31 Jul. 2010; B.N. Danforth leg.; CUIC * 2 2, 1 3; Cochise Co. Portal vicinity; 31°52.55'N, 109°03.46'W; 26 Jul. 2008; B.N. Danforth leg.; CUIC * 2 9; Cochise Co. Portal 6 mi E.; 31.876°N, 109.058°W; 29 Aug. 2010; J.L. Neff leg.; on Kallstroemia grandiflora; CTMI 34537 to 34538 2 3; same data as for preceding; CITMI 34539 to 34540 © 1 &; Cochise Co. Portal Rd. 1.4 mi. N. rd 80; 31.880°N, 109.036°W; 25 Jul. 2006; J. L. Neff leg.; on Kallstro- emia grandiflora, CTMI 31553 © 1 2; Cochise Co. Douglas 16 mi N; 31°28.10'N, 109°15.12'W; alt. 1250 m; 22 Jul. 2000. J. L. Neff leg.; on Kallstroemia grandiflora; CTMI 11971 ¢ 1 Q; Pima Co. Silver Bell, 5 mi E; 32.383°N, 111.417°W; 12 Aug. 1974; J. L. Neff leg.; on Kallstroemia grandiflora; CTMI 97071 © 2 C; same data as for preceding; 7-12 Aug. 1973; CTMI 102430 to 102431 ¢ 1 ; same data as for preced- ing; 28 Sep. 1974; CTMI 65420 1 4; Pima Co. Rillito; 34.208°N, 111.150°W; 17 Jul 1974; J. L. Neff leg.; on Kallstroemia grandiflora; CTMI 65570 © 1 Q; Pima Co. Silver Bell Bajada IBP Desert Scrub Site; J. L. Neff leg.; on Kallstroemia grandiflora; CTMI 97073. — New Mexico * 8 9, 3 G; same data as for holotype * 1 9; Hidalgo Co. 0.5 mi N Rodeo; 19 Sep. 2001; Danforth & Magnacca leg.; CUIC * 6 9, 3 4; Hi- dalgo Co. 7 mi N Rodeo; 31.933487°N, 109.024734°W; 27 Jul.2018; B.N. Danforth leg.; on Kallstroemia; CUIC © 7 9, 1 3; Hidalgo Co. Rodeo; 22 Sep. 1999; Danforth & Magnacca leg.; on Kallstroemia; CUIC * 2 9; Hidalgo Co. Rodeo 20 mi. N. San Simén Ciénaga; 12 Sep. 1999; Danforth & Magnacca leg.; CUIC * 9 9, 143 Hidalgo The North American species of the genus Ptilothrix 283 Co. Rodeo 4 mi N.; 18 Sep. 1999; Danforth & Magnacca leg.; on Kallstroemia; CUIC ¢ 1 9; Hidalgo Co. Rodeo 2 mi N; 15 Jul. 1974; JM Linsley leg.; on Kallstroemia gran- diflora; INHS 375568 ° 1 C; same data as for preceding; INHS 375569. Other material. Mexico — Sonora * 1 9; 30 km E Agua Prieta; 31°30'00"N, 109°28'00"W; 1 Aug 2001; E. Serrano leg., MCUR SBV069744 ¢ 1 9; same data as for preceding; MCUR SBV069979 « 1 9; same data as for preceding; MCUR SBV070114 © 1 Q; same data as for preceding; MCUR SBV070141 ¢ 1 9; same data as for preceding; 1-15 Aug. 2001; R.L. Minckley leg.; MCUR SBV079342 ¢ 1 9; same data as for preceding; MCUR SBV079339 © 1 Q; same data as for preceding; MCUR SBV079331 © 1 9; Rancho San Bernardino. 28 km E Agua Prieta, Ciénaga; 27 Jul. 2000; K Toal leg.; MCUR 1329 © 1 9; same data as for preceding; 10 Jul. 2000; MCUR 232 © 1 9; same data as for preceding; MCUR 2555 ® 1 9; same data as for preceding; MCUR 226 ¢ 1 9; same data as for preceding; MCUR 182. Unitep States of America — Arizona * 1 3; Portal. Cochise Co.; 7 May 1977; R Brooks leg.; on Kallstroemia; SEM 1304613 ¢ 1 4; Pima, San Luis Wash; 31.63227°N, 111.429°W; alt. 1038 m; 19 Aug. 2016; T.L. Griswold leg.; BBSL 1035487 ¢ 1 3; same data as for preceding; BBSL 1035497 3 CS: same data as for preceding; BBSL 1035575 to 1035577 © 1 9; same data as for preceding; BBSL 1035579 « 1 9; same data as for preceding; BBSL 1035496 ¢ 1 C; same data as for preceding; on Kallstroemia grandiflora; BBSL 1035010 ¢ 1 9; Pima, Brown Canyon; 31.75558°N, 111.525°W; alt. 1131 m; 21 Aug. 2016; T.-L. Griswold leg.; BBSL 1035607 * 1 9; same data as for preceding; BBSL 1035609 « 1 G; Pima; Tequila Tank, 0.67 air km ESE; 31.632°N, 111.444°W; alt. 1062 m; 19 Aug. 2016; T.L. Griswold leg.; BBSL 1035465 * 1 9; Cochise; Portal, 3.7 mi N; 31.959°N, 109.151°W; alt. 1412 m; 21 Aug. 2002; TLL. Griswold leg.; BBSL 689511 ¢ 1 9; same data as for preceding; BBSL 689526 ¢ 1 Q; same data as for preceding; BBSL 689530 — New Mexico ° 1 3; Hidalgo Co. 3 mi N Rodeo; 12 Aug.1978; R. Brooks leg.; on Kallstroemia; SEM 1304615 © 1 3; Hidalgo, Jct. Stateline & Hwy 80; 31.87985°N, 109.004°W; alt. 1250 m; 20 Aug. 2002; T.L. Griswold leg.; on Kallstroemia sp.; BBSL 689267 1 CS; same data as for preceding; BBSL 689295 © 1 4; same data as for preceding; BBSL 689301 © 1 9; same data as for preceding; BBSL 689297 ¢ 1 3; Hidalgo, Animas; 31.9292°N, 108.806°W;; alt. 1352 m; 18 Aug. 2002; T.-L. Griswold leg.; BBSL 690364 ¢ 1 9; same data as for pre- ceding; 31 Aug. 2002; BBSL 689365 © 1 9; same data as for preceding; BBSL 689368 — Texas * 2 Q; Jeff Davis Co. TNC Davis Mountains Preserve Mclvor Center vicinity; 8 Jul.- 27 Aug. 2022; J.A. Hanson, D. Heffern leg.; TAMU. Comments. P chirica/ua is associated to mixed Chihuahuan desert grassland habi- tats of Southern Arizona, New Mexico, Western Texas and Northern Mexico (Fig. 5). This species has been mainly collected on flowers of Kallstroemia grandiflora in the late summer/fall and, based on examination of scopal loads, appears to be a pollen special- ist on K. grandiflora. Butler (1967) and Michener (2007) also reported that this species has been collected in cotton flowers (Malvaceae). Etymology. This species is named in honor to the Chiricahua Apache people whose historical homeland encompasses the area where this bee now occurs. 28Nathalia Flérez-Gomez & Bryan Danforth / Journal of Hymenoptera Research 95: 275-293 (2023) @ Pitilothrix bombiformis & Ptilothrix sumichrasti %¢ Ptilothrix zacateca n. sp. @ Piilothrix chiricahua n. sp. Altitude 3000 m mal Om Figure 5. Distribution map of the North American species of the genus Ptilothrix: Ptilothrix chiricahua sp. nov., Ptilothrix zacateca sp. nov., Ptilothrix sumichrasti and Ptilothrix bombiformis. Ptilothrix zacateca sp. nov. https://zoobank.org/9A25784C-75A2-4BD3-978B-C9B17B25F1CD Figs 2C2 D3, Di4C, 5:6 Diagnosis. Female body size from 11.3-12.7 mm, male 10.5-13 mm. This species can be recognized by the overall whitish to pale yellowish pubescence, except for that on the female basitarsi, which is dark yellowish to pale brown. Differing from P sumi- chrasti and P. chiricahua by the longer first flagellomere (length at least twice its apical width), presence of erect, overall longer pubescence, especially on the anterior areas of T2 and T3, more robust body and slightly larger size. Both sexes with tergal hair bands on T1—T4 in females, T1—T6 in males. Description. Male. Total length 12.34 mm (paratypes 10.5—13 mm, n=7). Head. Integument black, except brown middle area of the mandible, mandibular apex yel- lowish in some paratypes. Uniformly whitish pubescence covering all of the head ex- cept ocellocular area where hairs are sparser. Mandible with rounded apical margin. Maxillary palpus 6-segmented. Labrum rectangular, disc densely punctate, margin raised and impunctate. Clypeus slightly protuberant in lateral view, with coarse punc- tation. Inner ocular margins subparallel. Frons, paraocular area and vertex with close punctures, separated by a distance up to a puncture diameter. Ocellocular integument micro—sculptured and with punctures towards the eye margin, small area around the lateral ocellus polished and shiny, distance 0.63 mm. Antennae black, scape 0.8 mm, The North American species of the genus Ptilothrix 285 first flagellomere 2.5 times longer than its apical width. Head length 3.25 mm. Head width 3.85 mm. Gena width 0.8 mm. Lower interocular distance 2.45 mm. Upper interocular distance 2.5 mm. Interocular distance 1.03 mm. Antennocular distance 0.41 mm. MOD 0.25 mm Mesosoma. integument black. Overall pubescence whitish on pronotum, scutum, scutellum, mesepisternum, metepisternum and propodeum; pale yellowish on the scu- tum of some specimens. Scutum with close punctures regularly distributed, separated by less than a puncture diameter with shiny interspaces. Scutellar punctures even more closely spaced than those of the scutum. Disc of mesepisternum punctured as in scu- tum, deep punctures and very close one to each other, imbricate interspaces between punctures. Hypoepimeral area deeply and densely punctate, micro—sculptured towards the scrobal groove. Propodeal triangle with whitish short pubescence, middle line gla- brous. Tegulae translucent brown. White tuft of hairs at the base of wings, membrane of wings slightly infuscate, venation brownish. Length of forewing 10.83 mm. Inter- tegular distance 3.25 mm. Scutum length 3.0 mm. Legs. Integument black to dark brown, except tarsi reddish brown. Pubescence whitish overall. Hind coxa and femur enlarged. Hind basitarsus slightly curved, 6 times the length of the second tarsomere. Hind tibial spurs dark brown, slightly hooked at the apex. Metasoma. Overall integument black, margin of sterna subhyaline. T1—T4 with dense, whitish erect pubescence, posterior margin with band of white hairs. T5—T6 with dense and erect black pubescence on the anterior area, margin with a band of whitish dense pu- bescence. I’7 covered with black pubescence, margin with two pointed projections forming a middle notch. Sterna with dense, whitish, erect pubescence. S6 with a median tuft of hairs. S7 and S8 as in Fig. 2C, D. Gonobase rounded, gonostylus filiform (Fig. 3C, D). Female. Total length 12.67 mm (11.3-12.7 mm n=8). Head. Integument color as in male, pubescence as in male, but less abundant. Mandible color and shape as in males. Labrum densely punctate, with subtriangular, raised, impunctate apex. Clypeus with coarse punctures separated by a distance up to twice a puncture diameter. Punc- tation of paraocular area and frons as in males, puncture size smaller than those on clypeus. Inner ocular margins nearly parallel. Integument of ocellocular area as in males, distance 0.76 mm. Antennae black, scape 0.93 mm long, first flagellomere 2.3 times longer than its apical width (Fig. 4C). Head length 3.48 mm. Head width 4.49 mm. Gena width 0.83 mm. Lower interocular distance 2.81 mm. Upper interocular dis- tance 2.85 mm. Interocular distance 1.22 mm. Antennocular distance 0.47 mm. MOD 0.30 mm. Mesosoma. Color, punctures and pubescence as in males, but pubescence shorter. Wing color and tegula as in male. Wings and tegula as in males. Length of fore- wing 10.62 mm. Intertegular distance 3.75 mm. Scutum length 3.37 mm. Legs. Overall black integument except brown tarsi. Hind tibia with whitish scopa, apical margin with a tuft of white pubescence, inner surface rugose and with short, whitish and appressed hairs. Scopa on hind basitarsus entirely dark yellowish to pale brown. Metasoma. In- tegument as in male. T1— T2 with erect whitish hairs, posterior margin with bands of whitish pubescence. T3 and T4 with whitish erect pubescence on the anterior area 28WNathalia Flérez-Gémez & Bryan Danforth / Journal of Hymenoptera Research 95: 275-293 (2023) Figure 6. Prilothrix zacateca sp. nov. A male holotype habitus, lateral view B male holotype habitus; frontal view C male holotype dorsal view D male holotype metasoma E female paratype habitus, lateral view F female paratype habitus, frontal view G female paratype dorsal view H female paratype metasoma. shorter than those in T1—T2, and with bands of pubescence. Prepygidial fimbria brown- ish, with whitish hairs intercalated laterally. Pygidial plate with rounded apex. Sterna with erect long, whitish—yellowish pubescence on the disc, denser at the margins. The North American species of the genus Ptilothrix 287 Material examined. Holotype. Mexico * 3; Zacatecas; Guadalupe; 28 Jun. 1953; C. & P. Vaurie leg.; D. Rockefeller Mex exped.; AMNH Paratypes. Mexico — Durango ¢ 2 3; 14 mi N.E of Durango; alt. 1889 m; 17 Jun. 1956; H.A. Scullen leg.; BBSL — Jalisco * 1 9; Villa Guadalupe; 26 Jul. 1951; H. E. Evans leg.; SEM SM0803860 ¢ 1 ; same data as for preceding; SEM SM0803859 — Zacatecas * 3 3; same data as for holotype * 6 Q; Fresnillo; alt. 2133 m; 15 Aug. 1947; C.D. Michener leg.; D. Rockefeller Mex exped.; AMNH. — Hidalgo « 1 9; 3 mi Pachuca; Kansas University Mexico exped.; 24 Jun. 1953; on Argemone; UCRC 546145 © 1 G; same data as for preceding; UCRC 546145. Comments. This species is endemic to Mexico. Records are from the mountain regions in the Sierra Madre Occidental from 1800—2000 m (Fig. 5). Its preferred host plants are unknown, although two specimens were collected on Argemone flowers, sug- gesting a possible association. But labels of most of observed material did not include information about related plants and specimens did not have pollen loads to facilitate these associations. It has been collected from June—August. Etymology. This species is named in honor to the Zacatecos, the indigenous group that inhabited the state of Zacatecas, the area where the holotype was collected. Ptilothrix sumichrasti Cresson, 1878 Figs 2h, E3Ey FR A4A5 5,7 Ptilothrix sumichrasti Cresson, E. T. (1878). (Lectotype: ANSP #f: Mexico). Diagnosis. Body size of females from 10—10.6 mm, males 8.2-10 mm. ‘This species is morphologically similar to P chiricahua but is recognizable by the punctation pat- tern in the ocellocular area, which is micro—sculptured, with punctures towards the eye margin and a small area around the lateral ocellus polished and shiny in both sexes. Males are clearly distinguishable by the brown pubescence covering T7, in addi- tion to the shape of S7, S8 and genital capsule (Figs 2E, F, 3E, F). This species shares with P chiricahua the following characters: fulvous pubescence on pronotum, scutum, scutellum, whitish towards the mesepisternum and propodeum. Metasoma with apical bands of yellowish appressed hairs from T1—T4. Anterior area of T3—T5 with black, short appressed hairs. First flagellomere length less than twice its apical width, being shorter than the rest of species in the genus Ptilothrix (Fig. 4A). Material examined. MrExico — Guerrero * 1 <; Iguala; CNIN 2887 — Micho- acan ° 1 9; La Mira, 4 km N Playa Azul; 2 Nov. 1987; T. Griswold leg.; BBSL 725135 ¢ 1 4; Los Amates, 26 km N Playa Azul; 2 Nov. 1987; T. Griswold leg.; on [pomoea; BBSL 725132 © 2 6; Caleta de Campos, 4 kmN Playa Azul; 3 Nov. 1987; T. Griswold leg.; BBSL 725133 to 725134 —Oaxaca ° | 3; 4 mi. N Pochutla. 11 Oct. 1975; J.L. Neff leg.; CIMI — Puebla ¢ 6 9; Tilapa, Carr. Fed. Azticar de Matamoros—Cuautla; 18°37.96'N, 98°34.96'W; 4 Sep.1998; T. Griswold leg.; BBSL 335125 to 335130. GUATEMALA ® 3 Q; C.A; alt. 300 m; 10 Jan.1923; AMNH 262013 to 262015. 28Nathalia Flérez-Gémez & Bryan Danforth / Journal of Hymenoptera Research 95: 275-293 (2023) Figure 7. Ptilothrix sumichrasti A female lectotype habitus, lateral view B female lectotype habitus; frontal view C female lectotype, dorsal view D female lectotype habitus metasoma E male habitus, lateral view F male habitus, frontal view G male dorsal view H male metasoma. Comments. Records of this species are from lowlands in Guatemala and Mexico in the Transmexican Volcanic Belt and the Balsas River Basin (Fig. 5), it is seemingly associated with flowers of Ipomoea and has been collected from October to January. The North American species of the genus Ptilothrix 289 Ptilothrix bombiformis Cresson, 1878 Figs*>; 6G; A, 7G, H,.8 Emphor bombiformis Cresson, 1878. Emphor fuscojubatus Cockerell, 1913. Ptilothrix bombiformis Cresson, (1878). (Lectotype: ANSP #f: Kansas, Snow). Diagnosis. Large bees, female body size from 13.5—19 mm, males from 12.5—18.6 mm. This species is clearly recognizable by the white to pale yellow pubescence on the head and mesosoma, and entirely black metasoma, except T1 which has whitish pubescence on the lateral sides in some specimens. Differs from P sumichrasti, P chiricahua and P. zacateca by the absence of yellowish metasomal bands, darkened wings, entirely black scopa, and overall larger size. First flagellomere length twice its apical width, as in other Ptilothrix species except P sumichrasti and P chiricahua. Shape of male S7, S8 and genital capsule as shown in Figs 2G, H, 3G, H. Material examined. UniteD Starrs or AMERICA — Alabama * 1 <4; Morgan; 34.6059°N, 86.9833°W; alt 178 m; Aug.1944; GE Bohart leg.; BBSL 511531 ¢ 2 9; Houston, Cowarts; 31.2°N, 85.3047°W, 1 Aug. 1916; AMNH 00260371 to 00260372. — Arkansas * 1 4; Monroe, Cotton Plant, 5.4 mi SWbS; 34.9327°N, 91.2726°W;; alt. 54 m; 21 Jul. 2015; PL. Stephenson leg.; BBSL 1027862 ¢ 1 &; same data as for preced- ing; BBSL 1027868 © 1 9; Prairie Des Arc, 6.8 mi SE, Cache River NWR; 34.9231°N, 91.3959°W; alt. 50 m; 24 Jun. 2015; PL. Stephenson leg.; BBSL 1027864 ¢ 1 CS; same data as for preceding; BBSL 1027863 ¢ 1 &; Monroe, Brinkley, 7.6 mi SW; 34.8521°N, 91.3242°W; alt. 49 m.; 16 Jul. 2015; PL Stephenson leg.; BBSL 1027865 ¢ 1 C; same data as for preceding; BBSL 1027867 ¢ 1 CS; St. Charles, 4.4 mi SWbS; White River NWR. 55 m. 34.3117, -91.1213. 24-VIU-2015. PL. Stephenson; BBSL 102786. — Illinois « 13 Q; Calhoun, Two Rivers NWR, HQ TI3S-RIW-S. 16; 38.94888°N, 90.5889°W; 2 Jul. 2012; B Loges leg.; AMNH 00260559 to 00260571 — Indiana 1 9; Ripley, Friend- ship; 38.9703°N, 85.1477°W, alt. 194 m; on Hibiscus syriacus; 29 Jul. 1950; LW Chan- dler leg.; BBSL 511562 — Iowa * 2 S; Louisa, Port Louisa NWR (HSB6) Rush Lake Rd.; 41.22°N, 91.12°W; 3 Jul. 2012; J Young; AMNH 00260557 to 00260558 — Kansas | 4; Crawford Pittsburg, 404 West Jefferson Street; 37.40049°N, 94.7119°W; alt. 286 m; on Hibiscus syriacus; 14 Jun. 2010; BBSL 1046881 ¢ 1 9; same data as for preceding; 15 Jul. 2003; BBSL 1046887 ¢ 2 3; same data as for preceding; 15 Jul. 2003; BBSL 1046885 to 1046886 © 2 4; Crawford, Pittsburg; 37.41092°N, 94.6993°W;; alt. 283 m; on Hibis- cus sp.; 20 Jul. 2003; BBSL 1046882 to 1046883 ¢ 2 9; Douglas, Lawrence, Mary's Lake; 38.9284°N, 95.2171°W; alt. 253 m; 8 Aug. 1996; B Alexander leg.; BBSL 207987 to 207988 — Kentucky ° 1 4; Franklin, Frankfort, Lakeview Park; 38.21638°N, 84.8303°W; alt. 231 m; 25 Jul. 1999; DM Gordon leg.; on Helianthus sp.; BBSL 1047096 ¢ 2 Q ; same data as for preceding; on Jpomoea sp.; 16-19 Jul. 2000; BBSL 1047109 to 1047110 e 7 4; same data as for preceding; BBSL 1047097 to 1047106 © 2 @ ; Franklin. Frank- fort, 504 Piaute Trail; 38.2149°N, 84.8362°W; alt. 227 m; 1 Jun 1999; DM Gordon leg,; BBSL 1047111 to 1047112 — Louisiana * 2 9; Saint Tammany, Abita Creek Preserve; 30.517°N, 89.967°W; 07 Aug. 2002; D Prowell leg.; on Hibiscus aculeatus; BBSL 664704 29(Nathalia Flérez-Gomez & Bryan Danforth / Journal of Hymenoptera Research 95: 275-293 (2023) Figure 8. Ptilothrix bombiformis A female lectotype habitus, lateral view B female lectotype habitus; frontal view C female lectotype, dorsal view D female lectotype habitus metasoma E male habitus, lateral view F male habitus, frontal view G male dorsal view H male metasoma. to 664705 * 2 3; same data as for preceding; BBSL 664706 to 664707 — Mississippi ° 1 Q; Pearl River, Poplarville; 30.84°N, 89.5342°W; alt. 102 m; 18 Aug.1998; B Samp- son leg.; on Hibiscus cannabinus; BBSL 511533 — Virginia « 1 9; Warren; 39.006°N, 78.07 1°W; alt. 159 m; 03 Aug. 2014; E Bodnar; BBSL 1096111. The North American species of the genus Ptilothrix 291 Comments. ‘This species is the most widely distributed in North America, its geo- graphical range from Ontario, Canada (Sharkey et al. 2020) to South Texas and Flor- ida (Fig. 5). It is mainly associated to flowers of Hibiscus, although occasionally visits species of Ipomoea. It is active mid— to late summer. Key to North American species of Ptilothrix 1 Metasoma with bands of yellowish or whitish pubescence from T1—T4; wings infuscate or subhyaline; female hind tibia with white or yellow scopa, yellow GL DLO wiisheOt: DasibarsUstmsse no. sex ascens tem Basscrn ett seds s,s haan Mace ates. RSs 2 = Metasoma pubescence entirely black, without bands, T1 sometimes with yel- low pubescence on lateral areas; wings darkened, female hind tibia and basi- tarsus with entirely black scopa.......sceseseseeeeeeeees Prilothrix bombiformis 2 First flagellomere up to two times longer than its apical width (Fig. 4A, B); T3 with appressed, short black pubescence on the anterior area, posterior margin with bands of yellow or white pubescence; body size of females from SiG) 1a, TH AIES*O LO OCITUINY sb eoacts undacet acon Soboee peu cnep eauay