Seven new species of Lasioglossum (Dialictus) Robertson, 1902 (Hymenoptera: Halictidae: Halictini) from the Yucatán Peninsula, Mexico Author Landaverde-González, Patricia CFEE1568-9AD9-4531-885D-EBF3F68ABB43 General Zoology, Institute for Biology, Martin-Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany. patricia.landaverde@zoologie.uni-halle.de Author Gardner, Joel AA15FE6E-921A-46D6-BC67-88E067F283D9 Department of Entomology, University of Manitoba, 12 Dafoe Rd., Winnipeg, Manitoba, R 3 T 2 N 2, Canada. clickbeetle3364@gmail.com Author Moo-Valle, Humberto 35656D9E-491C-4C34-8CAD-069E4B9F0E9B Departamento de Apicultura Tropical, Campus Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Mexico. moovalle@correo.uady.mx Author Quezada-Euán, José Javier G. BD9DBC7E-AD59-47BA-BA72-4A881A31E320 Departamento de Apicultura Tropical, Campus Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Mexico. javier.quezada@correo.uady.mx Author Ayala, Ricardo B1CFBA3B-C28B-40C5-B674-CBC8DB69418C Estación de Biología Chamela, Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 21, San Patricio Jalisco, 48980, Mexico. rayala@ib.unam.mx Author Husemann, Martin D31A05CA-DCD8-4CFB-A9D0-E9F070EC4707 Centrum für Naturkunde, University of Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany. martin.husemann@uni-hamburg.de text European Journal of Taxonomy 2023 2023-03-22 862 1 1 65 http://dx.doi.org/10.5852/ejt.2023.862.2079 journal article 264116 10.5852/ejt.2023.862.2079 957e3c13-6dd3-4b13-9576-9f013a4990bc 2118-9773 7767855 5D38246E-B144-434C-A2FE-C303381B0CD7 Lasioglossum ( Dialictus ) ameshoferi Landaverde-González sp. nov. urn:lsid:zoobank.org: act: 56635D12-86E3-4758-B5A1-BFE003DBAF00 Figs 5G–H , 6D , 13–14 , 25A , 26A , 34C Diagnosis Females of L. ( D. ) ameshoferi sp. nov. can be recognised by the combination of tegula small and ovoid with inner posterior angle not produced mesally (tegula width/ITS 0.21–0.22), clearly not reaching posterior margin of mesoscutum in dorsal view, and impunctate except for scattered minute punctures in anterior half; frons punctures as large and dense as those of lower paraocular area; mesoscutum with large, coarse and dense punctures (i <1 pd), crowded laterad of parapsidal lines (i = 0 pd) except on anteromedian margin (i> 1.5 pd); mesepisternum strongly rugose with the upper part areolate; metapostnotum shiny with strong subparallel rugae usually reaching posterior margin; and propodeum with strong U-shaped oblique carina sharply delineating metapostnotum. Males have the tegula small and ovoid (as in the female); frons punctures as large and dense as those of lower paraocular area, which is clearly visible beneath sparse appressed tomentum; metapostnotum with strong subparallel rugae reaching or nearly reaching posterior margin; and propodeum with trace of oblique carina present (this is unusual for males which almost always lack an oblique carina even when it is well-developed in the female). Differential diagnosis Both sexes of Lasioglossum ( Dialictus ) ameshoferi sp. nov. are most similar to L. ( D. ) nanotegula sp. nov. and females of L. ( D. ) milpa sp. nov. (the male is unknown). Females of L. ameshoferi are also similar to an undescribed species known from higher elevations in the mountains of Chiapas . Both sexes of L. ( D. ) nanotegula have the frons punctures much smaller and denser than those of the lower paraocular area, which in the male is partially obscured by dense appressed tomentum; females also have the propodeum with an oblique carina straight; and males have the propodeum without a trace of an oblique carina. Females of L. milpa also have the metapostnotum dull, imbricate, with shallow anastomosing rugae reaching posterior margin or nearly so and mesepisternum slightly sparsely punctate (i ≤ 1–1.5d), while females of L . nanotegula have the mesoscutum punctures laterad of the parapsidal lines moderately dense but not crowded (i ≤ 1 pd). Females of the undescribed Chiapas species have the frons punctures much smaller and denser than those of the lower paraocular area. Lasioglossum ameshoferi sp. nov. is very similar to the Panama species L. strigosigena Michener, 1954 , and diagnostic characters separating the two are not well known. It seems that the postgena of L. ameshoferi is mostly smooth, while in L. strigosigena it is entirely and strongly lineate, but a few specimens of L. ameshoferi approach the condition found in L. strigosigena . Geography is probably the most reliable way to separate these species. Etymology The specific epithet is dedicated to Andreas Ameshofer for his great support to PLG and his love and patience during the development of the entire study. Type material Holotype MEXICO – Campeche • ♀ ; Hopelchén ; 19.66° N , 89.66° W ; elev. 77 m ; 24 Jan. 2016 ; Misael Hdz leg.; ECOAB .82784. Paratypes GUATEMALA – Huehuetenango • 1 ♀ ; Jacaltenango , San Andrés ; 15.7167° N , 91.7455° W ; elev. 1027 m ; 28 Feb. 2010 ; Miguel Cigarroa leg.; ECOAB .44665 • 1 ♀ ; La Democracia , Unión ; 15.574° N , 91.8141° W ; elev. 1038 m ; 26 Feb. 2010 ; Jorge Mérida leg.; ECOAB .44666 • 1 ♀ ; San Antonio Huista , Pinalito ; 15.6653° N , 91.8618° W ; elev. 963 m ; 1 May 2010 ; Philippe Sagot leg.; ECOAB .44660 . MEXICO – Campeche • 1 ♀ ; Hopelchén ; 19.71° N , 89.8° W ; elev. 70 m; 2 Oct. 2015 ; Roberto May leg.; ECOAB .82345 • 1 ♀ ; Hopelchén ; 19.39° N , 89.71° W ; elev. 147 m; 4 Nov. 2015 ; Misael Hdz leg.; ECOAB .82585 • 1 ♀ ; Hopelchén ; 20.04° N , 89.74° W ; elev. 105 m; 22 Jan. 2016 ; Eric Vides leg.; ECOAB .82685 .– Chiapas • 1 ♀ ; 37 km E of Tuxtla Gutiérrez ; 16.75° N , 92.9167°W ;elev.1240 m; 12Apr. 1993 ; George C. Eickwort leg.; ex Senecio deppeanus ; SEMC SM0341238 • 1 ♀ ; Arriaga , Ej. Adolfo López Mateos ; 16.3463° N , 93.9741° W ; elev. 367.5 m; 15 Sep. 2009 ; Carlos Balboa , Miguel Guzmán and Miguel Cigarroa leg.; ECOAB .54267 • 1 ♀ ; Nicolás Ruiz and Carr. N. Ruiz-V. Guerrero ; 16.4238° N , 92.6326° W ; elev. 685 m; 29 Oct. 2011 ; Philippe Sagot leg.; ECOAB .53509 • 2 ♀♀ ; Ocozocoautla ; 16.84° N , 93.45° W ; elev. 836 m; 30 Dec. 2015 ; Philippe Sagot leg.; ECOAB .79338, 79346 • 1 ♀ ; Suchiapa ; 16.6294° N , 93.0916° W ; elev. 465 m; 8 Sep. 1987 ; L. Mendoza leg.; ECOAB .43998 • 1 ♀ ; Venustiano Carr. ; 16.49° N , 92.5° W ; elev. 1073 m; 31 Dec. 2016 ; Philippe Sagot leg.; ECOAB .67208 . – Colima • 1 ♀ ; San Antonio ; 19.4515° N , 103.7184° W ; elev. 1200 m; 10 Oct. 2008 ; Laurence Packer leg.; PCYU . – Guerrero • 2 ♀♀ ; 23 mi W of Acapulco ; [ 17° N , 100.2° W ]; 10 Aug. 1962 ; Ellen Ordway leg.; SEMC . – Jalisco • 1 ♀ ; Chamela ; [ 19.5° N , 105.04° W ]; 6 Jul. 1985 ; Ricardo Ayala Barajas leg.; ex Prockia crucis ; SEMC • 1 ♀ ; same collection data as for preceding; 17 Aug. 1985 ; SEMC . – Oaxaca • 1 ♀ ; Puerto Escondido ; [ 15.87° N , 97.08° W ]; elev. 10 m; 1 Sep. 1990 ; Luis M. Gódinez leg.; SEMC • 1 ♀ ; same collection data as for preceding; 30 Sep. 1990 ; SEMC . – Quintana Roo • 2 ♀♀ ; Tulum ; [ 20.21° N , 87.47° W ]; 22 Jan. 1976 ; L. Greenberg leg.; SEMC • 1 ♂ ; same collection data as for preceding; SEMC . – Yucatán • 1 ♂ ; Yucatán, Tixcuytun ; [ 20°12′21.80″ N , 89°09′17.50″ W ]; 7 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 293; UNAM (photographed) • 3 ♀♀ ; 30 mi S of Mérida ; [ 20.53° N , 89.61° W ]; 31 Jul. 1964 ; Paul J. Spangler leg.; USNM • 2 ♂♂ ; Chichén-Itzá ; [ 20.68° N , 88.57° W ]; 11 Jan. 1976 ; L. Greenberg leg.; SEMC • 1 ♂ ; Kabah , 25 km SW of Ticul ; [ 20.25° N , 89.65° W ]; 14 Feb. 1987 ; Charles D. Michener leg.; SEMC • 1 ♀ ; Mérida ; [ 20.97° N , 89.59° W ]; Nov. 1961 ; N.L.H. Krauss leg.; SEMC • 2 ♀♀ ; Uxmal Ruins, 16 km SW of Muna ; [ 20.36° N , 89.77° W ]; 14 Feb. 1987 ; Charles D. Michener leg.; SEMC • 1 ♀ ; Yaxnic ; [ 20.79° N , 89.62° W ]; 8 Apr. 1997 ; R.W. Brooks , H. Delphin , H. Contreras and U. Mao leg.; ex Acacia pennatula ; SEMC SM0106223 . Other material examined MEXICO - Yucatán • 1 ♀ ; Alfonso Caso ; [ 20° 05′02.5″ N , 89°09′39.3″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 113; ZMH 842030 • 1 ♀ ; Tah Dziú ; [ 20°10′06.9″ N , 88°55′36.2″ W ]; 7 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 241a1; ZMH 842033 • 1 ♂ ; Tixcacaltuyub ; [ 20°25′03.1″ N , 88°55′51.5″ W ]; 22 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 502a; ZMH 839502 • 1 ♀ ; Tixcuytun ; [ 20°11′25.30″ N , 89°10′29.30″ W ]; 22 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 493d; ZMH 63081 • 1 ♀ ; Alfonso Caso ; [ 20°05′02.5″ N , 89°09′39.3″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 89; ZMH 842065 • 1 ♀ ; Tixmehuac ; [ 20°15′52.4″ N , 89°08′58.1″ W ]; 22 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 411; ZMH 842067 • 1 ♀ ; Yucatán , Nenela ; [20°14.44′0.0″ N, 89°05′24.5″ W]; 9 May 2011 ; Quezada-Euán and Moo-Valle leg.; original label 2; UADY . Floral records ASTERACEAE Giseke : Senecio L.: S. deppeanus Hemsl. • FABACEAE Juss. : Acacia Mill. : A. pennatula (Schltdl. & Cham.) Benth. • SALICACEAE Mirb. : Prockia P. Browne ex L.: P. crucis P. Browne ex L. • SOLANACEAE Adans. : Capsicum L.: C. chinense Jacq. DNA barcodes Fourteen sequences are available (BOLD process IDs: BBLEG181-17, DIAL1304-08, GMMCK090-14, GMMCK130-14, GMMCK932-14, LDSPS110-15 to LDSPS118-15). These sequences are attributed to L. ameshoferi sp. nov. based on two specimens (BBLEG181-17, DIAL1304-08) that were examined and barcoded independently of the sequences from Yucatán ; the specimen corresponding to BBLEG181-17 is the holotype . Including the Yucatán sequences, there is a large amount of divergence (maximum intraspecific p-distance 4.21%; minimum interspecific p-distance (to L. aureoviride sp. nov. ) 5.92%). Within the Yucatán sequence there is also variation (maximun intraspecific p-distance 1.44%; minimum interspecific p-distance (to L. aureoviride ) 5.53%). Description Female ( holotype ) MEASUREMENTS. Length 5.47 mm ; head length 1.48 mm ; head width 1.6 mm ; fore wing length 3.7 mm . 15 female paratypes measured: length 5.01–5.47 mm ; head length 1.17–1.48 mm ; head width 1.22– 1.6 mm ; fore wing length 3.22–3.7 mm . COLOUR. Head and mesosoma metallic dark blue-green; clypeus apical half black; scape black, F1–F10 black dorsally, dark brown ventrally; tegula reddish brown; wing membrane subhyaline, subcosta black, venation and pterostigma otherwise brown; legs dark brown; metasoma black with apical margins of terga and sterna dark brown. PUBESCENCE. Whitish; head and mesosoma with abundant long pubescence (1–2.5 OD); gena with sparse appressed tomentum; propodeum with abundant plumose setae on lateral and posterior surfaces (1.5–2.5 OD); T1 with dense complete setose fan; T2–T3 with small basolateral patches of appressed tomentum covering less than half length of segment; T1–T2 evenly and densely covered by short simple setae, T3–T4 with similar setae but about twice as long; tarsal segments with plumose light-yellow setae. SURFACE SCULPTURE. Face with strong uniform large and dense punctation; clypeus shiny and densely punctate (i≤ 1 pd); supraclypeal area tessellate and sparsely punctate (i = 1–4 pd); upper paraocular area, frons, and ocellocular area shiny, with crowded punctures (i = 0 pd); lower paraocular area shiny and very densely punctate (i <0.5 pd); antennocular area imbricate and slightly less densely punctate (i ≤ 1 pd); gena and postgena finely lineate, becoming smooth and shiny on postgena anteriorly; mesoscutum tessellate, and large, coarsely and densely punctate (i <1 pd), becoming crowded laterad of parapsidal line (i = 0 pd) and slightly sparse on anteromedian margin (i> 1.5 pd); tegula impunctate except a few scattered minute punctures on anterior half; mesoscutellum coarsely and moderately sparsely punctate (i = 1–2 pd), becoming fine and dense (i <1 pd) on margins and median line; axilla shiny and densely punctate (i <1 pd); metanotum rugulose with abundant plumose setae; mesepisternum rugose with the upper part areolate; metepisternum rugose dorsally, weakly rugulose ventrally; metapostnotum shiny with coarse subparallel rugae reaching posterior margin; propodeum posterior surface smooth and tessellate; T1 anterior surface coriarious; T1–T2 shiny to weakly coriarious, and finely and sparsely punctate (i = 2–4 pd). Fig. 13. Lasioglossum ( Dialictus ) ameshoferi Landaverde-González sp. nov. , holotype, ♀ (ECOAB.82784). A . Lateral habitus. B . Dorsal habitus. C . Face. STRUCTURE. Head wide (length/width ratio = 0.91–0.98; holotype = 0.93); eyes weakly convergent below (UOD/LOD ratio = 1.19–1.46; holotype = 1.46); clypeus ¾ below suborbital tangent; antennal sockets close (IAD/AOD <1.18); frontal line ending 2.5 OD below median ocellus; gena wider than eye; tegula ovoid and relatively small, not produced mesally; inner metatibial spur pectinate, with three teeth; scutellum length 0.36; metapostnotum length 0.35, metapostnotum moderately long (MMR ratio = 1.03), posterior margin sharply angled onto posterior surface; propodeum with strong U-shaped oblique carina extending onto dorsolateral slope. Male MEASUREMENTS. Length 5.37– 3.85 mm ; head length 1.25–1.48 mm ; head width 1.43–1.58 mm ; fore wing length 2.59–3.5 mm . COLOUR. Head and mesosoma metallic dark turquoise-green to golden-green; clypeus apical half black; scape black, F1–F10 black dorsally, dark brown ventrally; tegula dark reddish brown; legs black with tarsi becoming dark reddish brown; metasoma black with apical rims of terga and sterna dark reddish brown. PUBESCENCE. Dull white; head and mesosoma with abundant long setae (1–2.5 OD); S3–S5 pubescence short (1–2 OD), suberect, and weakly plumose, appearing simple at <40 × magnification; face with sparse appressed tomentum below eye emargination; propodeum with abundant long plumose setae on lateral and posterior surfaces (1.5–2.5 OD); discs of metasomal terga with sparse, short, simple setae medially and longer plumose setae laterally (1–3 OD). SURFACE SCULPTURE. Clypeus shiny and densely punctate (i ≤ 1 pd); supraclypeal area tessellate and sparsely punctate (i = 1–3 pd); paraocular area, frons, and ocellocular area shiny with crowded punctures (i = 0 pd); gena and postgena finely lineate to imbricate; mesoscutum shiny and coarsely, moderately sparsely punctate (i = 1–2 pd); tegula impunctate; mesoscutellum coarsely and sparsely punctate (i = 2–4 pd), becoming dense on margins and median line (i <1 pd); metanotum areolate-rugulose; mesepisternum rugose and obscurely punctate; metapostnotum shiny with coarse and strong subparallel rugae reaching posterior margin; propodeum posterior surface shiny and finely, sparsely punctate (i = 1–3 pd), dorsolateral slope sometimes roughened by rugae reaching posterior margin, and with trace of oblique carina present (this is unusual for males which almost always lack an oblique carina even when it is well-developed in the female); discs of T1–T3 shiny and sparsely punctate in basal half (i = 1–3 pd), becoming very sparse in apical half (i = 2–4 pd); apical impressed areas impunctate. STRUCTURE. Head wide (length/width ratio = 0.80–0.81); eyes weakly convergent below (UOD/LOD ratio = 1.13–1.29); clypeus ¾ below suborbital tangent; antennal sockets close (IAD/AOD <0.48); frontal line ending 2.5 OD below median ocellus; gena wider than eye; tegula small and ovoid, not produced mesally and clearly not reaching posterior margin of mesoscutum in dorsal view; scutellum length 0.32; metapostnotum length 0.29, metapostnotum long (MMR ratio = 1.1), posterior margin gently angled onto posterior surface; genitalia with penis valve small and delicate, retrorse lobe small, gonostylus wider and rounded with a few short, simple setae near apex. Distribution Yucatán Peninsula and Pacific coast from Oaxaca to Jalisco . Remarks Uncommon. Lasioglossum ameshoferi sp. nov. has an unusual distribution which seems to cross from the Atlantic coast to the Pacific coast at the Isthmus of Tehuantepec. It is not known from the Atlantic coast west of the isthmus or the Pacific coast east of the isthmus. Specimens from both sides are nearly identical both morphologically and in their DNA barcodes, precluding any consideration of splitting the populations into separate species. It is possible that additional sampling will reveal a more extensive distribution. This species is a member of the informal L. comulum species group and corresponds to mOTU 7 in Landaverde-González et al . (2017a) .