Lasioglossum pavonotum (Cockerell 1925)

Lasioglossum pavonotum (Cockerell)

Halictus pavonotus Cockerell, 1925:188 [female, male].

Lasioglossum pavonotum.—Michener, 1951:1107 [Nearctic catalog].—Moldenke and Neff, 1974:55 [locality and flower records].—Hurd, 1979:1957 [Nearctic catalog].

TYPE MATERIAL.—The female holotype of Halictus pavonotus is in the California Academy of Sciences, San Francisco. It is in excellent condition and is labeled

San Francisco Ca.[ifornia] III-[March] 30-1913/EC Van Dyke Collectir [sic]/Halictus pavonotus Ckll. [Cockerell] TYPE [handwritten by Cockerell]/California Academy of Sciences Type No. 1650.

DISTRIBUTION (Figure 583).—Lasioglossum pavonotum is known only from sandy habitats immediately along the Pacific coastline and sand-banks along the Sacramento River. It is presently known only from Pacific County, Washington, south to Orange County, California, including San Miguel Island.

DIAGNOSIS.—Both sexes of Lasioglossum pavonotum are the only metallic blue-green bees of this genus in the New World. All other Lasioglossum species in the New World are dark brown to black, never metallic.

DESCRIPTION.—FEMALE: (1) Length 7.3–9.1 mm (x = 8.2, n = 15); (2) wing length 1.9–2.8 mm (x = 2.2, n = 15); (3) abdominal width 2.2–3.0 mm (x = 2.7, n = 15).

Structure: (4) Head elongate (Figure 584; length/width ratio 0.84–0.96, x = 0.92, n = 15). (7) Supraclypeal area evenly rounded, (8) moderately protuberant. (9) Clypeus projecting approximately 0.93 of its length below lower margin of eyes; (11) surface without median longitudinal sulcation. (14) Distance between lateral ocelli subequal to distance between lateral ocellus and eye. (23) Flagellomere 1 slightly longer than 2 along dorsal surface. Labrum as in Figure 586; (27) distal keel narrow in frontal view, nearly parallel-sided; (28) distal lateral projections well developed, rounded; (29) fimbrial setae acutely pointed; unlike other species, basal elevation of labrum not developed.

(32) Pronotal lateral angle narrowly obtuse; (33) pronotal lateral ridge incomplete, broadly interrupted by oblique lateral sulcus; (34) lower portion of lateral ridge inconspicuous, broadly rounded. (35) Mesoscutal lip weakly bilobed, (36) moderately elevated from pronotum. (40) Dorsal surface of propodeum about 0.75 the length of scutellum and about 1.2 times the length of metanotum, (41) slightly depressed centrally, (42) posterior margin broadly rounded; (43) propodeal triangle weakly defined laterally, evident medially as a conspicuous, sharply edged V-shaped elevation with lateral rims, fading towards metanotum; (44) lateral carinae extending to or slightly beyond midpoint of posterior surface. (45) Tibial spur as in Figure 47.

(46) Lateral edge of metasomal tergum II broadly rounded with posterior half somewhat truncated.

Sculpture: (47) Face shiny, (48) densely punctate below ocelli, punctures contiguous, becoming only slightly larger and less dense near antennae. (51) Supraclypeal area extremely granulate; (52) punctures separated by their width laterally, becoming less dense centrally. (53) Clypeus granulate basally, apical half weakly granulate, somewhat polished; (54) punctures obscure, becoming very sparse apically. (56) Mesoscutum shiny; (57) punctation as in Figure 589, punctation uniform, contiguous, becoming granuloso-punctate anteriorly. (58) Scutellum nearly uniformly punctate, punctures less dense than those of mesoscutum, separated by their width or slightly less. (63) Dorsal surface of propodeum (Figure 588) striolate to ruguloso-striolate laterally, becoming rugulose medially, striae and rugulae reaching posterior margin only laterally; (64) surface alveolated. (65) Metasomal tergum 1 shiny, granulate; (66) punctation extremely fine, obscure, moderately sparse posteriorly, punctures 1–2 times their width apart, surface impunctate centrally and anteriorly (forming weakly developed acarinarium, see species discussion).

Coloration: (71) Wing membrane hyaline.

Vestiture: (74) Pubescence of head white. (75) Pubescence of thorax white; (76) mesoscutal hairs moderately dense, conspicuously plumose. (77) Hind tibial hair color very weakly differentiated, hairs mostly white, dorsal hairs light brown. (78) Anterior hairs of metasomal tergum I and (79) basal hair bands of terga II—IV white. (80) Acarinarium not obviously developed (mites attach to impunctate median area of tergum I, base of tergum I with scattered elongate hairs as in non-mite-carrying species, Figure 591); metasoma highly unique in having lateral patches of adpressed, short, white hairs at anterior edges of tergum I (similar to basal hair band of L. sisymbrii but interrupted), apical edges of metasomal terga with short white hair fringe; basal hair bands of terga II–IV weakly defined, that of tergum IV nearly covering entire surface.

MALE: Similar to female except as follows: (1) length 6.7–8.4 mm (x = 7.4, n = 15); (2) wing length 1.7–2.2 mm (x = 1.9, n = 15). (3) abdominal width 1.6–2.1 mm (x = 1.9, n = 15). (4) Head as in Figure 585 (length/width ratio 0.86–0.95, x = 0.91, n = 15). (5) Gena subequal to eye in width, (6) rounded, not produced posteriorly. (10) Clypeal surface with conspicuous median depression on ventral half. Labrum as in Figure 587; (24) distal process very weakly developed, rounded; (25) basal area rounded medially, not depressed; (26) basal lateral depressions absent. (30) Mandible very short, not quite reaching opposing clypeal angle. (53) Clypeus polished; (54) punctation nearly uniform throughout, punctures slightly less dense apically and on apical median depression. (68) Clypeal maculation absent. (69) Flagellum slightly paler on venter than on dark dorsum. (72) Tarsi dark, concolorous with tibiae.

Vestiture: Sternal vestiture as in Figure 590; (82) hairs on sternum IV adpressed, elongate, curling inward towards midline; (83) hairs on sternum V similar to those on sternum V but with median rosette of short hairs.

Terminalia: Sterna VII–VIII as in Figure 596; (85) sternum VIII without median process. Genitalia as in Figures 592–595; (86) gonobase moderately short; (87) gonostylus enormous, subequal in size to retrorse membranous lobe; (89) retrorse membranous lobe moderately slender, conspicuously hairy; (90) volsella with broadly rounded lateral lobe.

FLIGHT RECORDS (Figure 597).—Lasioglossum pavonotum females have been collected from February to early November, with records from California peaking in April, whereas those from Oregon and Washington peak in early June. Male records peak in August but range from early March through October.

FLOWER RECORDS.—Females (65): Compositae 49%; Polygonaceae 18%; Leguminose 15%; Papaveraceae 9%. Males (21): Compositae 67%; Aizoaceae 14%; Hydrophyllaceae 14%. Total: 86 in six families, 13 genera as follows:

Achillea 2; *Agoseris 5(3); Baccharis 1;, Eriogonum 12; *Escholtzia 6(2), 1; Grindelia 4, 13; *Hypochoeris 4(3); Layia 4; *Lupinus 9(1); Malacothrix 13; Meliotus 1; Mesembryanthemum 1, 3; Phacelia 4, 3.

MITE ASSOCIATES.—The acarinarium of female L. pavonotum is very weakly developed, represented only by a glabrous median area of the anterior surface of metasomal tergum I (Figure 591). Only 10.4% of the females and 5.3% males examined in this study carried mites.

SPECIMENS EXAMINED.—845 (619 226).

UNITED STATES. CALIFORNIA: Contra Costa Co.: including Antioch; Del Norte Co.: Cresent City; Humboldt Co.; Los Angeles Co.; Marin Co.; Mendocino Co.; Monterey Co.; Orange Co.: Newport Beach; San Francisco Co.; San Luis Obispo Co.; San Mateo Co.; Santa Clara Co.: Saratoga; Santa Cruz Co.: Ano Nuevo State Beach, Davenport; Santa Barbara Co.: including San Miguel Island and Santa Rosa Island; Sonoma Co.: Bodega Bay, Dillon Beach. Stillwater Cove; Ventura Co.: Oxnard, Point Mugu Naval Air Station, Ventura. OREGON:coos Co.: Bandon; Curry Co.: Gold Beach; Lane Co.: Florence, Westlake; Lincoln Co.: Newport, Pacific City, Waldport, Yachats: Tillamook Co.: Newport, Pacific City, Waldport, Yachats; Tillamook Co.: Sand Lake, Tierra del Mar, 3 mi N.WASHINGTON:Gray's Harbor Co.: Copalis; Pacific Co.: Nahcotta, ocean Park.

Lasioglossum pavonotum is a species of sweat bee in the family Halictidae.