Lasioglossum (Sphecodogastra) texanum ( Cresson 1872 )

Gibbs, Jason, Packer, Laurence, Dumesh, Sheila & Danforth, Bryan N., 2013, Revision and reclassification of <i> Lasioglossum </ i> (<i> Evylaeus </ i>), <i> L. </ i> (<i> Hemihalictus </ i>) and <i> L. </ i> (<i> Sphecodogastra </ i>) in eastern North America (Hymenoptera: Apoidea: Halictidae), Zootaxa 3672 (1), pp. 1-116 : 74-77

Lasioglossum (Sphecodogastra) texanum ( Cresson 1872)

( Figs. 43H , 44H , 45H , 46H , 50 , 51 )

Sphecodes texanus Cresson 1872, p. 249 ♂

Lectotype. ♀ USA, Texas, Bosque Co. (G. W. Belfrage) [ ANSP 2134 ]. Designated by Cresson (1916). Examined by JG 2008.

( Labels read “Tex./ Lectotype 2134 [red label]/ Sphecodes Cress. , 2 specimens [handwritten on folded label]/ ANSP [yellow label]”) .

Evylaeus texanus (in Bohart & Youssef 1976: new combination)

Halictus texanus (in Cockerell 1898c: new combination)

Halictus (Parasphecodes) texanus (in Cockerell 1898a: subgeneric placement)

Halictus (Megalopta) texanus (in Stevens 1920: subgeneric placement)

Lasioglossum (Sphecodogastra) texana [sic] (in Linsley & MacSwain 1962: key)

Lasioglossum (Sphecodogastra) texanum (in Michener 1951: catalogue; Krombein 1967:catalogue)

Sphecodogastra texana (in Ashmead 1899: genus description; Mitchell 1960: redescription, key ♂; McGinley 2003: redescription, key ♂)

Diagnosis. Both sexes of L. texanum are easily recognised by the enormous ocelli, with diameters exceeding the ocellocular distance ( Figs. 43H , 44H ). Female L. texanum can also be recognised by the combination of compound eyes convergent below ( Fig. 43H ), metasoma orange-red ( Fig. 50 ), and tibial scopa a single row of rake-like hairs (as in Fig. 74B ). In the east, female L. texanum are most likely to be mistaken for L. swenki based on colour pattern, but the latter has normal ocelli and scopa (as in Fig. 74A ). West of the Mississippi River, L. texanum females are most similar to L. noctivaga , which have elongate mandibles and eyes divergent below.

Male L. texanum can only be distinguished from L. noctivaga by genitalia. The retrorse lobe is broad and twisted in L. texanum ( Fig. 46H ) and narrow and untwisted in L. noctivaga .

Description. See McGinley (2003: 47).

Taxonomic notes. Lasioglossum texanum is the type species of Sphecodogastra by original designation and monotypy ( Ashmead 1899).

Biology. Lasioglossum texanum is a nocturnal/crepuscular species, with distinct periodicity to its behaviour associated with lunar cycles ( Kerfoot 1967a). Foraging occurs during twilight but extends later into the night if the moon is visible before twilight ends. Cell provisioning is limited to periods when the moon is present at twilight ( Kerfoot 1967a, b). Nests are simple tunnels in sandy soil with cells constructed at the ends of distinct lateroids ( Hicks 1936; Kerfoot 1967b). Females do not prepare cell closures; instead filling the lateroids with loose soil ( Kerfoot 1967b). Lasioglossum texanum is a solitary nester ( Kerfoot 1967b); when two females were detected in a single nest (approximately one third of excavated nests in Kansas), one always appeared to be recently emerged. One nest of thirty-three excavated had two fertilized females and two newly emerged females ( Kerfoot 1967b). This species is oligolectic on Onagraceae , primarily Oenothera ( Kerfoot 1967b; McGinley 2003).

DNA barcodes. No specimens have been sequenced.

Range. Fig. 52 .

Specimens examined. 126 (110 females, 16 males). ANSP, CUIC, EMEC, LACM, MSUC, and UCRC. See McGinley 2003 for additional records.

USA. COLORADO: Boulder Co.: Boulder, 5500’; White Rocks ; El Paso Co.: Foster Ranch; Huerfano Co.: 2 mi W Walsenberg; Kiowa Co.: Eads; Lake Co.; E of Lake George; Lake George; ILLINOIS: Mason Co.: Mason S.F; KANSAS: Marshall Co.: Blue Rapids; Pottawatomie Co.: Little Gobi Des.; Reno Co.: Hutchinson; Summer Co.: Wellington; NEBRASKA: Cherry Co.: Mt. Gordon Creek; Cuming Co.: West Point; Dawes Co.: Chadron; Eddy Co.: Artesia; Keith Co.: Cedar Point Biol. Sta., 5 mi N Ogallala; Lancaster Co.: Lincoln; Lincoln Co.: Hondo; Scotts Bluff Co.: Mitchell; NEW MEXICO: Dona Ana Co.: Mesilla, Las Cruces; Eddy Co.: Malaga, 7 mi. W; Union Co.: Clayton Lake, 12 mi. NW of Clayton; OKLAHOMA: Caddo Co. : Hinton; Okmulgee Co.: Okmulgee; Payne Co.: Stillwater; SOUTH DAKOTA: Fall River Co.: Angostura Dam; TEXAS: Brazos Co.: Bryan; Brewster Co.: Alpine; Dimmit Co.: Tex. Exp. Sta.; Galveston Co.: Dickinson; Gonzales Co.: Luling; Palmetto S.P.; Howard Co.: Big Spring, 1 mi. NW; Jeff Davis Co.; Fort Davis; Kerr Co.: Kerrville; Lamar Co.: Paris; San Patricio Co.: Port Aransas; Randall Co.: Palo Duro S.P., nr. Canyon; Val Verde Co.: Del Rio; WYOMING: Converse Co.: Box Elder Creek.

Figures

FIGURE 43. Faces of female Lasioglossum subgenera Evylaeus (A) and Sphecodogastra (B-I) in frontal view. (A) L. cinctipes. (B) L. boreale. (C) L. comagenense. (D) L. lusorium. (E) L. oenotherae. (F) L. quebecense. (G) L. seillean. (H) L. texanum (I) L. truncatum. Scale bar = 1 mm.

FIGURE 44. Faces of male Lasioglossum subgenus Evylaeus (A) and Sphecodogastra (B-I) in frontal view. (A) L. cinctipes. (B) L. boreale. (C) L. comagenense. (D) L. lusorium. (E) L. oenotherae. (F) L. quebecense. (G) L. seillean. (H) L. texanum (I) L. truncatum. Scale bar = 1 mm.

FIGURE 45. Genital capsules of male Lasioglossum subgenera Evylaeus (A) and Sphecodogastra (B-I) in dorsal view. (A) L. cinctipes. (B) L. boreale. (C) L. comagenense. (D) L. lusorium. (E) L. oenotherae. (F) L. quebecense. (G) L. seillean. (H) L. texanum (I) L. truncatum. Scale bar = 1 mm.

FIGURE 46. Genital capsules of male Lasioglossum subgenus Evylaeus (A) and Sphecodogastra (B-I) in ventral view. (A) L. cinctipes. (B) L. boreale. (C) L. comagenense. (D) L. lusorium. (E) L. oenotherae. (F) L. quebecense. (G) L. seillean. (H) L. texanum (I) L. truncatum. Scale bar = 1 mm.

FIGURE 50. Lateral habitus of female Lasioglossum (Sphecodogastra) texanum (Cresson). Scale bar = 1 mm.

FIGURE 51. Lateral habitus of male Lasioglossum (Sphecodogastra) texanum (Cresson). Scale bar = 1 mm.

FIGURE 52. Distribution map of Lasioglossum (Sphecodogastra) texanum (Cresson). Heat map indicates predicted suitable range based on maximum entropy niche-modelling. Black circles indicate actual geo-referenced specimen records.

FIGURE 74. Scopa of hind leg. (A) L. boreale—unmodified scopa. (B) L. oenotherae—modified scopa for Onagraceae pollen collection.