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 ) yucatanense Landaverde-González sp. nov. urn:lsid:zoobank.org:act: F9897B79-0567-4EAB-802A-1E0C1B4D65E1 Figs 1 , 5A–B , 6A , 7–8 , 30B , 36A Diagnosis Females of L. yucatanense sp. nov. can be recognized by the vertex and mesoscutum having very short, sparse pubescence, as if shaved (most noticeable in lateral view where most setae are separated by half or more their length); mesosoma entirely dulled by strong microsculpture; mesoscutum usually densely punctate laterad of parapsidal lines (i <1 pd) and sometimes partially shiny (especially posteromedially); mesepisternum strongly imbricate to finely rugulose with indistinct punctures at least in dorsal portion; tegula enlarged (reaching posterior margin of mesoscutum in dorsal view; tegula width/ITS> 0.23) and distinctly, densely punctate on lateral margins (i <1 pd), becoming more sparsely punctate medially (i ≥ 1 pd), sometimes densely punctate medially (i <1 pd); metapostnotum with fine rugae extending onto propodeum dorsolateral slope; discs of T1–T2 with very fine, minute punctures, often hardly visible; and T2 and usually T3 apical impressed areas glabrous and impunctate. Males can be recognized by the same characters as females, except that the mesepisternum is shiny and distinctly and densely punctate (i <1 pd). Differential diagnosis Both sexes of L. yucatanense sp. nov. are most similar to Lasioglossum paxtoni sp. nov. and L. aureoviride sp. nov. and some members of the L. stictaspis species complex in the Yucatán Peninsula. They are also similar to the Nearctic species L. perparvum , which does not co-occur with L. yucatanense , and some undescribed species related to L. perparvum which may co-occur with L. yucatanense at the limits of its range. Both sexes of L. paxtoni have the tegula more finely and sparsely, sometimes inconspicuously punctate (i = 1–2 pd on lateral margins), mesonotum and mesoscutum shiny, mesoscutum finely and sparsely punctate (i = 1–3 pd) becoming slightly denser laterad of parapsidal lines (i = 1–2 pd); females also have the mesepisternum shiny, granular and finely, moderately densely punctate. Lasioglossum aureoviride females have the mesoscutum weakly tessellate and sparsely punctate between parapsidal lines (i = 1–3 pd), T2–T3 apical impressed areas evenly covered with minute punctures and fine setae, head and mesosoma metallic dark turquoise-green with golden reflections on mesoscutum, and mesepisternum very densely punctate (i <0.5 pd). Both sexes of the L. stictaspis species complex have the mesoscutum with longer and denser pubescence (in lateral view all setae separated by less than half their length); females also have the mesepisternum usually imbricate and deeply, moderately densely punctate (i ≤ 1.5 pd) with distinct interspaces and T2–T3 apical impressed areas usually with minute punctures or setae; males also usually have the mesepisternum more sparsely punctate (i = 1–2 pd). Females of L. perparvum have the mesepisternum distinctly punctate and T2–T3 apical impressed areas with minute punctures; males have T1–T2 with deep and distinct punctures often extending across premarginal line onto apical rim. Other undescribed species may have the tegula much larger (exceeding posterior margin of mesoscutum in dorsal view) and/or entirely densely punctate (i <1 pd); propodeum dorsolateral slope smooth without metapostnotal rugae; and/or mesepisternum shiny and distinctly punctate. Etymology The specific epithet refers to the Yucatán Peninsula region, Mexico where the species was discovered. The name was proposed by Manfred Stark who won a photo competition to name a species of bee at an event at the ZMH. Type material Holotype MEXICO – Yucatán • ♀ ; Nenela ; [ 20.3364° N , 89.022° W ]; 25 Oct. 2011 ; Quezada-Euán and MooValle leg.; original label 435.2; UNAM . Paratypes GUATEMALA – Huehuetenango • 1 ♀ ; Jacaltenango ; 15.7167° N , 91.7455° W ; elev. 1027 m ; 28 Feb. 2010 ; César López leg.; ECOAB .43352 • 1 ♀ ; La Democracia , Calauté ; 15.571° N , 91.8496° W ; elev. 915 m ; 27 Apr. 2010 ; Jorge Mérida leg.; ECOAB .43257 • 1 ♀ ; La Democracia , Camojaíto ; 15.616° N , 91.8727° W ; elev. 940 m ; 1 Mar. 2010 ; Philippe Sagot leg.; ECOAB .43199 . MEXICO – Campeche • 1 ♂ ; Hopelchén ; 19.58° N , 89.77° W ; elev. 110 m ; 25 Jan. 2016 ; Jesús López leg.; ECOAB .82805 . – Chiapas • 1 ♀ ; 3 km N of San Francisco Pujiltic , SW of Soyatitán ; [ 16.3° N , 92.44° W ]; elev. 710 m ; 21 Apr. 1993 ; R.W. Brooks leg.; ex Bidens bipontina ; SEMC SM0341500 • 2 ♀♀ ; 3 km S of Palenque , Nututún ; [ 17.485° N , 91.975° W ]; elev. 40 m ; 25 Apr. 1993 ; R.W. Brooks leg.; ex Bidens pilosa ; SEMC SM0341501 , SM0341502 • 5 ♂♂ ; same collection data as for preceding; SEMC SM0341706 to SM0341710 • 2 ♀♀ ; 5 mi S of Pichucalco ; 17.4369° N , 93.1019° W ; elev. 2137– 2286 m ; 13 Sep. 1974 ; George E. Bohart and W.J. Hanson leg.; BBSL 1101064 , 1101065 • 2 ♂♂ ; same collection data as for preceding; BBSL 1101060 , 1101061 • 51 ♀♀ ; 52.9 km N of Ocosingo Shanil ; [ 17.2167° N , 92.1° W ]; elev. 320 m ; 23 Apr. 1993 ; R.W. Brooks leg.; ex Bidens ; SEMC • 43 ♂♂ ; same collection data as for preceding; SEMC • 4 ♀♀ ; 52.9 km N of Ocosingo Shanil , near Agua Azul ; 17.2167° N , 92.1° W ; elev. 320 m ; 23 Apr. 1993 ; E. Tovar leg.; ex Bidens pilosa ; SEMC SM0341611 to SM0341614 • 4 ♀♀ ; Bonampak ; [ 16.71° N , 91.06° W ]; 23–26 Sep. 1977 ; W.D. Edmonds leg.; SEMC • 2 ♀♀ ; Estación Biológica Chajul , near Chajul ; [ 16.113° N , 90.941° W ]; elev. 200 m ; 15 Apr. 1993 ; R.W. Brooks leg.; ex Oenothera sp. ; SEMC SM0341481 , SM0341482 • 1 ♂ ; same collection data as for preceding; SEMC SM0341819 • 1 ♂ ; Ocosingo , El Rosario ; 16.8859° N , 92.2742° W ; elev. 1118 m ; 15 Apr. 2010 ; Miguel Guzmán leg.; ECOAB .43132 • 1 ♂ ; Ocosingo , San Francisco ; 16.9156° N , 92.0483° W ; elev. 922 m ; 11 Feb. 2010 ; Miguel Cigarroa leg.; ECOAB .43016 • 1 ♂ ; Ocozocoautla ; 16.98° N , 93.54° W ; elev. 985 m ; 8 May 2016 ; Philippe Sagot leg.; ECOAB .66283 • 2 ♂♂ ; Palenque ; 17.5083° N , 91.9815° W ; 10 Sep. 1974 ; George E. Bohart and W.J. Hanson leg.; BBSL 1101051 (photographed), 1101057 • 1 ♀ ; San Juan Cancuc , Chijil ; 16.947° N , 92.4087° W ; elev. 1095 m ; 8 Apr. 2010 ; Carlos Balboa leg.; ECOAB .43222 • 3 ♀♀ ; San Juan Cancuc , Tzuluwitz ; 16.894° N , 92.4019° W ; elev. 1270 m ; 5 May 2009 ; Jorge Mérida , César López and T. López leg.; ECOAB .42642, ECOAB .42651, ECOAB .42655 • 1 ♂ ; San Juan Cancuc , Tzumbal ; 16.9394° N , 92.4434° W ; elev. 1080 m ; 6 Apr. 2010 ; Carlos Balboa leg.; ECOAB .42996 • 1 ♂ ; Socoltenango ; 16.17° N , 92.37° W ; elev. 609 m ; 14 Jan. 2017 ; Philippe Sagot leg.; ECOAB .67384 • 1 ♂ ; Tzimol ; 16.15° N , 92.32° W ; elev. 617 m ; 15 Jan. 2017 ; Philippe Sagot leg.; ECOAB .67480 . – Puebla • 8 ♂♂ ; 3 km S of Venustiano Carranza ; [ 20.48° N , 97.67° W ]; 30 Apr. 1984 ; J.C. Schaffner leg.; TAMU-ENTO X1387389, X1395191, X1395942, X1395974, X1396008, X1396057, X1397280, X1397583 • 1 ♀ ; 3mi SW of Cuetzalán (N of Zacapoaxtla ); [ 19.99° N , 97.56° W ]; elev. 1250 m ; 19 Jun. 1961 ; University of Kansas Mexico Expedition leg.; SEMC • 1 ♀ ; 5 mi E of Huauchinango ; [ 20.18° N , 97.98° W ]; elev. 1250 m ; 25 Jun. 1953 ; University of Kansas Mexico Expedition leg.; SEMC • 3 ♂♂ ; same collection data as for preceding; SEMC • 2 ♀♀ ; N of Cuetzalan ; 20.1042° N , 97.489° W ; elev. 160 m ; 4 Jul. 2011 ; Jason J. Gibbs leg.; WRME . – Quintana Roo • 1 ♀ ; 12 km NW of Reforma ; [ 18.89° N , 88.65° W ]; 14 Oct. 1986 ; Charles D. Michener leg.; SEMC • 2 ♀♀ ; 49 km NE of Felipe Carrillo Puerto ; [ 19.89° N , 87.71° W ]; 11 Oct. 1986 ; Charles D. Michener leg.; SEMC • 3 ♂♂ ; Felipe Carrillo Puerto ; 19.35° N , 88.03° W ; 10–14 Oct. 1986 ; F.D. Parker leg.; BBSL 1100926 , 1100927 , 1100931 • 2 ♀♀ ; same collection data as for preceding; 10–14 Oct. 1986 ; BBSL 1100919 , 1100932 • 4 ♀♀ ; Reforma ; [ 18.81° N , 88.57° W ]; 14 Oct. 1986 ; Charles D. Michener leg.; SEMC • 14 ♂♂ ; Xcan ; [ 20.87° N , 87.6° W ]; 31 Jul. 1962 ; A . B. Amerson Jr. leg.; SEMC . – San Luis Potosi • 1 ♀ ; 12 km NW of El Naranjo ; [ 22.59° N , 99.38° W ]; elev. 400 m ; 5 Jul. 1990 ; Robert L. Minckley leg.; SEMC • 1 ♀ ; 2 mi NE of El Salto falls ; [ 22.61° N , 99.36° W ]; 21 Jul. 1962 ; Ellen Ordway Roberts leg.; ex Helenium sp. ; SEMC • 8 ♀♀ ; 20 mi NE of Ciudad del Maíz ; [ 22.61° N , 99.38° W ]; elev. 914 m ; 19 Jun. 1953 ; University of Kansas Mexico Expedition leg.; SEMC • 8 ♀♀ ; 3.4 mi NE of El Naranjo ; [ 22.56° N , 99.3° W ]; elev. 244 m ; 5 Sep. 1962 ; University of Kansas Mexico Expedition leg.; SEMC • 6 ♂♂ ; same collection data as for preceding; SEMC • 2 ♀♀ ; 30 mi NE of Ciudad del Maíz ; [ 22.7° N , 99.27° W ]; elev. 396 m ; 19 Jun. 1953 ; University of Kansas Mexico Expedition leg.; SEMC • 1 ♀ ; 9 mi S of Ciudad Valles ; [ 21.9° N , 98.92° W ]; elev. 183 m ; 2 Sep. 1962 ; University of Kansas Mexico Expedition leg.; SEMC • 2 ♀♀ ; El Meco (near El Salto Falls ); [ 22.57° N , 99.35° W ]; elev. 350 m ; 5 Jul. 1990 ; Ilan Yarom leg.; SEMC • 25 ♀♀ ; El Salto ; [ 22.59° N , 99.38° W ]; elev. 549 m ; 8 Jun. 1961 ; University of Kansas Mexico Expedition leg.; ex Kallstroemia hirsutissima ; SEMC • 13 ♀♀ ; same collection data as for preceding; SEMC • 1 ♂ ; same collection data as for preceding; SEMC • 3 ♂♂ ; same collection data as for preceding; SEMC • 1 ♀ ; El Salto Falls ; [ 22.59° N , 99.38° W ]; elev. 400 m ; 4 Jul. 1990 ; Ilan Yarom leg.; SEMC • 1 ♂ ; same collection data as for preceding; 5 Jul. 1990 ; SEMC • 1 ♀ ; Pujal ; [ 21.85° N , 98.94° W ]; 20 Jun. 1953 ; University of Kansas Mexico Expedition leg.; SEMC • 1 ♀ ; Tamazunchale ; [ 21.26° N , 98.79° W ]; 18 Jun. 1937 ; SEMC • 2 ♀♀ ; Xilitla ; [ 21.385° N , 98.975° W ]; elev. 442 m ; 23 Jul. 1954 ; University of Kansas Mexico Expedition leg.; SEMC • 4 ♂♂ ; same collection data as for preceding; SEMC . – Tabasco • 1 ♀ ; 2 mi SW of Frontera ; [ 18.51° N , 92.67° W ]; 7 Sep. 1968 ; Veryl V. Board leg.; TAMU-ENTO X1313226 • 1 ♂ ; same collection data as for preceding; TAMU-ENTO X1313330 • 1 ♂ ; Villahermosa ; [ 17.99° N , 92.95° W ]; Oct. 1954 ; N.L.H. Krauss leg.; SEMC . – Tamaulipas • 1 ♀ ; 10 km W of Antiguo Morelos , Highway 80; [ 22.555° N , 99.167° W ]; elev. 470 m ; 6 Jul. 1990 ; Ilan Yarom leg.; SEMC • 1 ♂ ; 6 mi W of Gómez Farías ; [ 22.89° N , 99.12° W ]; 5 Jul. 1986 ; J.C. Schaffner and Kovarik leg.; TAMU-ENTO X1413144 • 1 ♀ ; El Limón; [ 22.82° N , 99.01° W ]; 17 Jun. 1953 ; University of Kansas Mexico Expedition leg.; SEMC • 2 ♂♂ ; same collection data as for preceding; SEMC • 3 ♀♀ ; Gómez Farías ; 23.0475° N , 99.1556° W ; 14 Feb. 2001 ; Douglas Yanega leg.; UCRC ENT 49797 to ENT 49799 • 5 ♀♀ ; Padilla ; [ 24.05° N , 98.9° W ]; 15 Jun. 1953 ; University of Kansas Mexico Expedition leg.; SEMC • 1 ♂ ; same collection data as for preceding; SEMC • 1 ♀ ; W of Gómez Farías ; [ 23.03° N , 99.16° W ]; 15 Nov. 1985 ; P.W. Kovarik , Jones and Haack leg.; TAMU-ENTO X1414798 . – Veracruz • 5 ♀♀ ; 12 mi NW of San Andrés Tuxtla ; [ 18.56° N , 95.32° W ]; elev. 335 m ; 24 Jun. 1961 ; University of Kansas Mexico Expedition leg.; SEMC • 1 ♀ ; 15 mi W of Tlapacoyan ; 19.8232° N , 97.2246° W ; 28 Feb. 1972 ; F.D. Parker and D. Miller leg.; BBSL 1101047 • 1 ♀ ; 15 mi W of Veracruz ; [ 19.17° N , 96.36° W ]; elev. 15 m ; 30 Jun. 1953 ; University of Kansas Mexico Expedition leg.; SEMC • 4 ♀♀ ; 17 mi NW of San Andrés Tuxtla ; [ 18.545° N , 95.39° W ]; elev. 274 m ; 24 Jun. 1961 ; University of Kansas Mexico Expedition leg.; SEMC • 1 ♂ ; same collection data as for preceding; SEMC • 2 ♀♀ ; 2 mi N of Jesús Carranza ( Isthmus of Tehuantepec ); [ 17.47° N , 95.03° W ]; elev. 46 m ; 25 Jun. 1961 ; University of Kansas Mexico Expedition leg.; SEMC • 2 ♀♀ ; 3 mi SW of Paso del Toro ; [ 19° N , 96.17° W ]; elev. 15 m ; 23 Jun. 1961 ; University of Kansas Mexico Expedition leg.; ex Porophyllum ; SEMC • 2 ♀♀ ; same collection data as for preceding; SEMC • 1 ♀ ; 32 km N of Catemaco , UNAM Preserve ; [ 18.58° N , 95.07° W ]; 4 Jan. 1982 ; John W. Wenzel leg.; SEMC • 1 ♀ ; same collection data as for preceding; 9 Jan. 1982 ; E.M. May leg.; SEMC • 4 ♀♀ ; 34 km SE of Catemaco , 1 km along road to Montepio ; [ 18.21° N , 94.88° W ]; 3 Jan. 1982 ; B.H. Smith leg.; SEMC • 4 ♀♀ ; 4 mi W of Puente Nacional ; [ 19.32° N , 96.55° W ]; elev. 274 m ; 22 Jun. 1961 ; University of Kansas Mexico Expedition leg.; ex Kallstroemia hirsutissima ; SEMC • 1 ♂ ; 5 mi SW of Tlapacoyan ; [ 19.91° N , 97.27° W ]; elev. 853 m ; 26 Jun. 1953 ; University of Kansas Mexico Expedition leg.; SEMC • 3 ♂♂ ; 7 mi NW of Alazán , near Tuxpan ; [ 21.16° N , 97.81° W ]; 11 Jun. 1961 ; University of Kansas Mexico Expedition leg.; ex Lippia sp. ; SEMC • 2 ♂♂ ; Alazán ; 21.0917° N , 97.7255° W ; 27 Feb. 1972 ; F.D. Parker and D. Miller leg.; BBSL 1101044 , 1101045 • 1 ♀ ; Balzapote , NE of Estación Los Tuxtlas ; [ 18.62° N , 95.07° W ]; 17 Sep. 1987 ; A . L. Norrbom leg.; USNM • 1 ♀ ; Boca del Río ; [ 19.11° N , 96.11° W ]; elev. 8 m ; 23 Jun. 1961 ; University of Kansas Mexico Expedition leg.; ex Acacia ; SEMC • 1 ♀ ; Huatusco ; 19.1734° N , 96.9724° W ; 11 Jan. 2007 ; Sam W. Droege leg.; PCYU USGS-DRO 074912 • 1 ♂ ; Veracruz ; [ 19° N , 96° W ]; 1959; N.L.H. Krauss leg.; USNM . – Yucatán • 1 ♀ ; 6 km E of Uxmal ; [ 20.36° N , 89.71° W ]; 6 Apr. 1997 ; R.W. Brooks leg.; ex Vitex gaumeri ; SEMC SM0105999 • 1 ♂ ; Xmatkuil , 15 km S of Mérida ; [ 20.86° N , 89.62° W ]; 13 Feb. 1987 ; Charles D. Michener leg.; SEMC • 1 ♀ ; Chichén-Itzá ; [ 20.68° N , 88.57° W ]; 11 Jan. 1976 ; L. Greenberg leg.; SEMC • 1 ♂ ; same collection data as for preceding; SEMC • 2 ♂♂ ; Chichén-Itzá ruins (near Piste ); [ 20.68° N , 88.57° W ]; 15 Feb. 1987 ; Charles D. Michener leg.; SEMC • 2 ♀♀ ; Kabah , 25 km SW of Ticul ; [ 20.25° N , 89.65° W ]; 14 Feb. 1987 ; Charles D. Michener leg.; SEMC • 4 ♂♂ ; same collection data as for preceding; SEMC • 2 ♂♂ ; San Simón Pueblo ; 20.2159° N , 89.8098° W ; 22 Jan. 1981 ; George E. Bohart leg.; BBSL 1101107 , 1101108 • 1 ♀ ; Timul ; 20.3156° N , 88.9322° W ; 9 Jun. 2011 ; José J.G. Quezada-Euán and Humberto Moo-Valle leg.; original label 300C2; ZMH 842012 • 1 ♀ ; same collection data as for preceding; original label 300d; ZMH 842013 . Other material examined MEXICO – Guerrero • 1 ♀ ; Acapulco ; [ 16.9° N , 99.9° W ]; Baker leg.; USNM . – Jalisco • 1 ♀ ; Careyes ; 19.4289° N , 105.0274° W ; 12 Feb.–19 Mar. 1997 ; F.D. Parker leg.; BBSL 1100768 . – Yucatán • 1 ♀ ; Nenela ; [ 20°20′10.90″ N , 89°1′19.20″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 344a; ZMH 842014 • 1 ♀ ; Yaxcopil ; [ 20°4′4.10″ N , 88°54′23.80″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 602C; ZMH 81028 • 1 ♂ ; Nenela ; [ 20°20′10.90″ N , 89°01′19.20″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 68a; ZMH 81027 • 1 ♀ ; Timul ; [ 20°18′56.1″ N , 88°55′55.9″ W ]; 9 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 300a; ZMH 839500 • 1 ♀ ; Nenela ; [ 20°15′10.0″ N , 89°05′24.5″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 65a1; ZMH 842000 • 1 ♀ ; Nenela ; [ 20°15′10.0″ N , 89°05′24.5″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 65a2; ZMH 842001 • 1 ♀ ; Nenela ; [ 20°15′10.0″ N , 89°05′24.5″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 68c; ZMH 842002 • 1 ♀ ; Alfonso Caso ; [ 20°05′02.5″ N , 89°09′39.3″ W ]; 25 Oct. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 77; ZMH 842003 • 1 ♀ ; Moctezuma ; [ 21°24′46.2″ N , 87°42′05.7″ W ]; 30 May 2011 ; Quezada-Euán and Moo-Valle leg.; original label 148; ZMH 842004 • 1 ♀ ; Moctezuma ; [ 21°24′46.2″ N , 87°42′05.7″ W ]; 30 May 2011 ; Quezada-Euán and Moo-Valle leg.; original label 153; ZMH 842005 • 1 ♀ ; San Pedro Bacab ; [ 21°18′04.9″ N , 087°38′24.8″ W ]; 31 May 2011 ; QuezadaEuán and Moo-Valle leg.; original label 169; ZMH 842006 • 1 ♀ ; San Pedro Bacab ; [ 21°18′04.9″ N , 087°38′24.8″ W ]; 31 May 2011 ; Quezada-Euán and Moo-Valle leg.; original label 173; ZMH 842007 • 1 ♀ ; Rancho Alegre ; [ 21°18′26.7″ N , 87°46′29.6″ W ]; 13 Aug. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 213; ZMH 842008 • 1 ♀ ; same collection data as for preceding; original label 216; ZMH 842009 • 1 ♀ ; Tah Dziú ; [ 20°10′06.9″ N , 88°55′36.2″ W ]; 6 Jun. 2011 ; Quezada-Euán and MooValle leg.; original label 240a; ZMH 842010 • 1 ♀ ; Timul ; [ 20°18′56.1″ N , 88°55′55.9″ W ]; 9 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 299e; ZMH 842011 • 1 ♀ ; Tixcuytun ; [ 20°12′21.80″ N , 89°09′17.50″ W ]; 7 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 432.1; ZMH 842015 • 1 ♀ ; Tixcuytun ; [ 20°12′21.80″ N , 89°09′17.50″ W ]; 7 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 433a; ZMH 842016 • 1 ♀ ; Tixcuytun ; [ 20°12′21.80″ N , 89°09′17.50″ W ]; 7 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 433b; ZMH 842017 • 1 ♀ ; Tixcuytun ; [ 20°12′21.80″ N , 89°09′17.50″ W ]; 7 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 435; ZMH 842018 • 1 ♀ ; Tah Dziú ; [ 20°10′06.9″ N , 88°55′36.2″ W ]; 6 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 473; ZMH 842019 • 1 ♀ ; Tixcuytun ; [ 20°12′21.80″ N , 89°09′17.50″ W ]; 7 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 488a2; ZMH 842020 • 1 ♀ ; Muna ; [ 20°28′15.7″ N , 89°46′53.5″ W ]; 22 Jul. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 569d; ZMH 842021 • 1 ♀ ; Santa María ; [ 20°23′32.5″ N , 88°55′14.6″ W ]; 26 Jul. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 587f; ZMH 842022 • 1 ♀ ; same collection data as for preceding; original label 590a; ZMH 842023 • 1 ♀ ; Yaxcopil ; [ 20°4′4.10″ N , 88°54′23.80″ W ]; 1 Aug. 2011 ; Quezada-Euán and MooValle leg.; original label 603a; ZMH 842024 • 1 ♀ ; Timul ; [ 20°18′56.1″ N , 88°55′55.9″ W ]; 9 Jun. 2011 ; Quezada-Euán and Moo-Valle leg.; original label 300d; ZMH 842013 . Floral records ASTERACEAE Giseke : Bidens L.: B. bipontina Sherff • B. pilosa L. • Helenium L.• Porophyllum Guett. • FABACEAE Juss. : Acacia Mill. • LAMIACEAE Martinov : Vitex L.: V. gaumeri Greenm. • ONAGRACEAE Juss. : Oenothera L. • SOLANACEAE Adans. : Capsicum L.: C. chinense Jacq. • VERBENACEAE J. St. -Hil.: Lippia L. • ZYGOPHYLLACEAE R. Br. : Kallstroemia Scop. : K. hirsutissima Vail. DNA barcodes Thirty sequences available, two haplotypes (BOLD process IDs: LDSPS002-15 to LDSPS008-15, LDSPS010-15 to LDSPS028-15 (haplotype 1); DLII504-07, DLIII127-18, DLIII137-19, DLIII138-19 (haplotype 2). The holotype GenBank accession number: KU574888. BOLD process ID: LDSPS009-15. Haplotype 1 is morphologically and genetically similar to haplotype 2 with a large number of sequences available (consistent with the relative abundance of specimens of L. yucatanense sp. nov. ). The sequences are highly variable (maximum intraspecific p-distance between haplotypes 3.53%; within haplotype 1 intraspecific p-distance 0.54%; minimum interspecific p-distance (to L. paxtoni sp. nov. ) 2.89%). Two reasons that may influence the high intraspecific variation are the existence of cryptic species throughout the distribution of these taxa and problems in the quality of the sequence data for the Yucatán specimens. Description Female ( holotype ) MEASUREMENTS. Length 3.88 mm ; head length 1.08 mm ; head width 1.14 mm ; forewing length 3.1 mm ; 14 female paratypes measured: length 3.88–4.91 mm ; head length 1.08–1.18 mm ; head width 1.14– 1.24 mm ; fore wing length 2.85–4.96 mm . COLOUR. Head and mesosoma dark metallic green with copper-red reflections on mesoscutum; clypeus basally metallic green and apically black; scape and pedicel dark brown; F1–F10 dark brown dorsally, light brown ventrally; tegula dark reddish brown; wing membrane subhyaline, venation and pterostigma reddish brown; legs black with tarsal segments light brown; metasoma black with apical rims of terga and sterna dark brown. PUBESCENCE. Light yellow. Head and mesosoma with abundant setae (1–2 OD), very short and sparse on vertex and mesoscutum (i ≤ 1 OD), most setae on mesoscutum separated by half their length or more in lateral view and subappressed setae little more than stubble, appearing shaved; lower paraocular area with sparse subappressed tomentum and gena with sparse erect setae; propodeum with plumose setae on lateral and posterior surfaces, more scattered on the latter (2–2.5 OD); T1 with dense complete setose fan; T2–T3 with small and short basolateral patches of appressed tomentum covering less than half length of segment and usually apical rims glabrous and impunctate; discs of T2–T6 with sparse, short, simple setae; apical impressed areas glabrous except T3–T4 with sparse apicolateral setae. SURFACE SCULPTURE. Clypeus and supraclypeal area shiny and moderately densely punctate (i = 1–2 pd); lower paraocular area shiny and densely punctate (i ≤ 1d); antennocular area imbricate and densely punctate (i ≤ 1pd); upper paraocular area, frons, and ocellocular area shiny and densely punctate (i <1d); gena and postgena lineate; tegula larteral margin with deep, distinct, and dense punctures (i <1d) slightly larger than mesoscutum punctures, sparse medially (i = 1–3 pd); mesoscutum tessellate and finely and densely punctate laterad of parapsidal lines (i ≤ 1pd), becoming sparse and obscure anteromedially (i = 1–3 pd); mesoscutellum tessellate and coarsely, irregularly, sparsely punctate (i = 1–5 pd); axilla similar to mesoscutellum; metanotum finely rugulose-punctate; mesepisternum strongly imbricate to finely rugulose and densely punctate (i ≤ 1 pd), punctures shallow and indistinct on ventral half and dorsal margin; metepisternum finely rugulose; metapostnotum dull, finely reticulate with fine subparallel rugae reaching posterior margin; propodeum dorsolateral slope strigate; discs of metasomal terga shiny to finely coriarious with minute, shallow, sparse punctures (i = 1–4 pd); apical impressed areas impunctate; T2 and usually T3 apical rims impunctate; metasomal terga polished from T4–T6 with irregularly distributed punctures. STRUCTURE. Head wide (length/width ratio = 0.95–0.98; holotype = 0.95); eyes weakly convergent below (UOD/LOD ratio = 1.25–1.35; holotype = 1.35); apicolateral margins of clypeus strongly convergent; antennal sockets close (IAD/AOD = 0.57–0.7); frontal line ending 2.5 OD below median ocellus; gena narrower than eye; inner metatibial spur pectinate with four teeth; tegula relatively large, reaching posterior margin of mesoscutum in dorsal view, with inner posterior margin straight, more bean-shaped; scutellum length 0.23; metapostnotum length 0.2, metapostnotum moderately elongate (MMR ratio = 1.15), posterior margin sharply angled onto posterior surface; propodeum with oblique carina, lateral carina nearly reaching margin of dorsal surface. Male MEASUREMENTS. Length 3.60–3.80 mm ; head length 1.05– 1.18 mm ; head width 1.11–1.48 mm ; fore wing length 2.57–3.03 mm . COLOUR. Head and mesosoma dark metallic blue-green with copper-red reflections on mesoscutum; antenna dorsal side dark brown and ventral side light brown; tegula dark brown; wing membrane light brownish, venation and pterostigma brown; legs dark brown; metasoma black with apical rims of terga and sterna dark brown. PUBESCENCE. Light brown.Head with abundant setae (0.5–1OD),more abundant, forming dense tomentum in paraocular and supraclypeal areas; gena with sparse setae; mesoscutum with sparse plumose setae 0.5–1 OD long (most setae separated by half their length or more in lateral view, especially in posterior half); propodeum with plumose setae on lateral and posterior surfaces, sparser on the latter (0.5–1 OD); discs of metasomal terga with sparse short setae; apical impressed areas impunctate; T2–T3 basolateral margins with a few sparse tomentose setae. SURFACE SCULPTURE. Clypeus, supraclypeal area, paraocular area, and ocellocular area shiny and densely punctate (i <1 pd); frons dull with crowded punctures (i = 0 pd); gena and postgena lineolate; tegula lateral margin with deep, distinct, and dense punctures (i <1d) slightly larger than mesoscutal punctures, moderately dense medially (i = 1–2 pd); mesoscutum shiny to weakly tessellate and densely punctate (i ≤ 1 pd), becoming more strongly tessellate and slightly sparser anteromedially (i = 1–2 pd); mesoscutellum shiny to weakly tessellate and densely punctate (i ≤ 1pd); metanotum rugulose; mesepisternum shiny and densely punctate (i <1 pd); metepisternum rugulose; propodeum with dorsolateral slope strigate, metapostnotum somewhat shiny, finely and weakly reticulate with strong subparallel rugae; metasomal terga shiny with minute, shallow, sparse punctures (i = 1–4 pd). STRUCTURE. Head wide (length/width ratio = 0.94–0.98). Eyes weakly convergent below (UOD/LOD ratio = 1.65–1.69); antennal sockets slightly separated (IAD/AOD <1.07); frontal line ending 2.5 OD below median ocellus; tegula relatively large, reaching posterior margin of mesoscutum in dorsal view, with inner posterior margin straight or concave; scutellum length 0.22; metapostnotum length 0.19, metapostnotum elongate (MMR ratio = 1.16), posterior margin sharply angled onto posterior surface; genitalia with penis valve short, delicate and thin; retrorse lobe of genital capsule of median size and width, gonostylus small, fine and rounded, with a few short, simple setae near apex; S7–S8 median processes narrow. Fig. 7. Lasioglossum ( Dialictus ) yucatanense Landaverde-González sp. nov. , holotype, ♀ (435.2 UNAM). A . Lateral habitus. B . Dorsal habitus. C . Face. Distribution Widely dispersed throughout the eastern lowlands of Mexico from Tamaulipas to Yucatán and Chiapas and in northwestern Guatemala . Two outliers from Jalisco and Guerrero are morphologically Fig. 8. Lasioglossum ( Dialictus ) yucatanense Landaverde-González sp. nov. , ♂ (BBSL 1101051). A . Lateral habitus. B . Dorsal habitus. C . Face. indistinguishable from the eastern specimens; it is unclear whether these represent long-range dispersal events, a natural range extension, or a cryptic species. Remarks Very common. Specimens of both DNA barcode haplotypes are morphologically indistinguishable, but geographically separate. All haplotype 1 sequences are from Yucatán while haplotype 2 is from Puebla , Veracruz , and Chiapas . It is possible that these represent cryptic species; however, the geographic separation disappears when considering all available specimens (with barcodes or not). Yet, the variation between haplotypes could be reinforced, mainly when considering genetic variation, following the findings from other species of bees and insects in the region ( Landaverde-González et al . 2020 ; Urueña et al . 2022 ). Thus, in order to be conservative, it is inadvisable to consider a two-species hypothesis at this time. This species is a member of the L. gemmatum species complex and corresponds to mOTU 1 in Landaverde-González et al . (2017a) .