Osmia (Diceratosmia) marilaunidii Rightmyer 2017, new status
Creators: name: Rightmyer, Molly G.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Megachilidae
Osmia
Osmia marilaunidii

description: Osmia (Diceratosmia) marilaunidii Cockerell, new status
(Figs 1A, 2A, 7A, 12B)
Osmia conjuncta marilaunidii Cockerell 1914: 363 [Holotype male: Washington, D.C.]; Sandhouse 1939: 140 [synonymy with O. subfasciata and O. botitena]; Michener 1949: 261 [rejection of synonymy with O. subfasciata, agreement of synonymy with O. botitena].
Diagnosis. Like most Diceratosmia, females and males of O. marilaunidii are relatively small (intertegular distance ca. 2 mm in females, 1.8 mm in males) and have metallic blue integument. Osmia marilaunidii females can be distinguished from all other small, blue Diceratosmia except O. conjuncta by the combination of the following characters: the lack of modified hairs on the face (hairs long and tapering, not short and stout or corkscrew shaped) and scopa (hairs tapering, not swollen or blunted at apical tips), and lack of a carinate omaulus (i.e., lateral and anterior surfaces of the mesepisternum joined by smoothly rounded curve). Osmia marilaunidii can be separated from O. conjuncta by subtle but consistent features of the mandible and T1: in O. marilaunidii, the carina at the base of the third tooth (forming the adjacent apical margins of the second and fourth teeth) forms a semi-half circle, while in O. conjuncta this carina is nearly straight to forming at most one-fourth of a circle; the anterior surface of T1 is polished and shiny in O. marilaunidii, while in O. conjuncta the anterior surface is shagreened and dull.
Males of O. marilaunidii can be distinguished from all other small, blue/green Diceratosmia except O. conjuncta and O. gonzalezi by the combination of the following characters: the apical margin of S3 is strongly emarginate; the lateral projections of T6 each form an acute angle similar to the submedian tooth found on the apical margin of T7; and S4 has hairs at its midpoint that are long and slender, and which do not form a dense comb (males of the larger, blue-greenish O. exquisita are unknown). Osmia marilaunidii and O. conjuncta differ from O. gonzalezi by the sculpturing of the frons between the punctures (shiny and polished in O. marilaunidii and O. conjuncta; dull and granulose in O. gonzalezi), as well as the presence of a large, hairless area on each side of the apical margin of S 4 in O. marilaunidii and O. conjuncta (i.e., with these hairless areas distinctly separating the hairs at the middle of the apical margin from the hairs found at the extreme sides of the apical margin; hairs continuous across apical margin in O. gonzalezi). Osmia marilaunidii and O. conjuncta can be separated by differences in integument sculpture on the scape and T1, and punctation patterns on the metepisternum and S4: in O. marilaunidii the integument is shiny on the scape and anterior surface of T1 (dull in O. conjuncta); the metepisternum is much less densely punctate than the center of the lateral surface of the mesepisternum (density of punctures subequal between these two areas in O. conjuncta); and the subapical margin of S4 has a large impunctate area on either side of the median area bearing long hairs (these lateral impunctate areas lacking or much reduced in O. conjuncta).
Distribution. Texas, USA and adjacent Mexico (Nuevo Leon) (Fig. 16).
Floral Associations. Asteraceae: Gaillardia suavis; Boraginaceae: Phacelia; Cactaceae: Opuntia phaeacantha; Fabaceae: Lupinus texensis, Prosopis laevigata, Vicia ludoviciana; Lamiaceae: Brazoria truncata, Salvia texana; Malvaceae: Sphaeralcea pedatifida; Onagraceae: Calylophus serrulatus.
Material Examined. Mexico. Nuevo Leon: Linares, 4 km S, 22 Mar 1991, R Brooks; Nuevo Laredo, 15 mi S, 22 Feb 1972, FD Parker, DR Miller; Sabinas, 15 mi S Hidalgo, 23 Feb 1972, FD Parker, DR Miller. Tamaulipas: Rio Corona, 18 mi N Ciudad Victoria, 13 Apr 1979, G Valle. USA. Texas: Bexar Co, Salado Creek, 1 Apr 1957, BF Eldridge; Bexar Co, Salado Creek, 1 Apr 1957, J Kesser; Brazos Co, 9 Apr 1963 AH Alex; Cameron Co, Santa Maria, 28 Mar 1951, RH Beamer; Denton Co, Rainbow Valley Agricutural CoOp, 27 Apr 2002, H Ikerd; Dimmit Co, Chaparral Wildlife Management Area, 15 Mar 1977, TP Friedlander; Ellis Co, Avalon, 25 Jun 1988, JG Rozen; Gillespie Co, Kerrville, 10 mi N, 22 Apr 1953, RH Beamer; Hidalgo Co, Bentsen Rio Grande Valley State Park, 25 May 1972, CC Porter; Hidalgo Co, Bentsen Rio Grande Valley State Park, 15 Mar 1979, C Porter; Hidalgo Co, Bentsen Rio Grande Valley State Park, 15 Mar 1983, C Porter; Hidalgo Co, McAllen Botanical Garden at McAllen, 24 Mar 1984, C. Porter; Hidalgo Co, McAllen Botanical Garden at McAllen, 19 Mar 1983, C. Porter; Hidalgo Co, McAllen Botanical Garden at McAllen, 20 Mar 1976, C. Porter; Hidalgo Co, McAllen Botanical Garden at McAllen, 20 Mar 1983, C. Porter; Hidalgo Co, McAllen Botanical Garden at McAllen, 26 Mar 1978, C. Porter; Hidalgo Co, McAllen Botanical Garden at McAllen, 19 May 1983, C. Porter; Kerr Co, Kerrville, 22 Apr 1953, LD Beamer; Kerr Co, Kerrville, 23 Apr 1953, LD Beamer; Lee Co, Fedor, Birkman; Lee Co, Giddinas, 12 May 1953, RH Beamer; Maverick Co, Eagle Pass, 28 Mar 1946, CD Michener; Menard Co, Menard, 14 mi S, 2 Jun 1975, CD Michener; Refugio Co, Tivoli, 5 mi SW, 18 Apr 1952, Michener, Beamers; Stonewall Co, 16 Apr 1953, LD Beamer; Travis Co, Austin, 2 May 1980, PD Hurd; Austin, Brackenridge Field Lab, 13 Mar 1975, GJ Steck; Zapata Co, San Ygnacio, 15 Apr 1952, Michener, Beamers; Zavala Co, Crystal City, 14 Apr 1952, Michener, Beamers.
Comments. Osmia marilaunidii has been viewed incorrectly as a synonym of O. botitena which is here synonymized with O. subfasciata (See comments under O. subfasciata). This species nests in snail shells (Cane et al. 2007 as O. botitena).
description: Published as part of Rightmyer, Molly G., 2017, A revision of the subgenus Osmia (Diceratosmia), with descriptions of four new species (Hymenoptera, Megachilidae), pp. 1-37 in Zootaxa 4337 (1) on pages 17-18, DOI: 10.11646/zootaxa.4337.1.1, http://zenodo.org/record/1014033