Lasioglossum stictaspis (Sandhouse, 1923)

Gardner, Joel & Gibbs, Jason, 2023, Revision of the Nearctic species of the Lasioglossum (Dialictus) gemmatum species complex (Hymenoptera: Halictidae), European Journal of Taxonomy 858 (1), pp. 1-222 : 11

Lasioglossum stictaspis species complex

Species included

Lasioglossum angelicum sp. nov., L. cupreicollis (Friese, 1917) , L. diabolicum sp. nov., L. paululum ( Sandhouse, 1924) , and L. stictaspis ( Sandhouse, 1923) .

Diagnosis

The L. stictaspis species complex is a subset of the L. gemmatum complex defined by a cluster of highly similar DNA barcodes (BOLD BINs: ABX4912, AEC8768) containing numerous ʻmixtureʼ associations (as in Ratnasingham & Hebert 2013). No single combination of morphological characters reliably distinguishes the group, but most members have the tegula relatively large compared to most other species of L. gemmatum complex (maximum length half or more ITS and reaching or exceeding posterior margin of mesoscutum in dorsal view) and densely punctate (IS <1 PD) (except L. diabolicum sp. nov.), face short (length/width ratio usually <0.83 in females and <0.86 in males), gena narrower than eye in lateral view, mesoscutum with abundant plumose pubescence about 1 OD long, T2–T4 with abundant tomentum and dense simple setae, and males with dense tomentum covering the face up to level of eye emargination.

Lasioglossum cupreicollis is included in this group with some trepidation, as the holotype was not available for examination and no known DNA barcodes are available. However, images of the holotype of Halictus goethalsi Cockerell, 1928 (considered a junior synonym of L. cupreicollis by Michener 1954) were seen, and it closely resembles some members of the L. stictaspis complex. One male specimen from Colombia also has a DNA barcode available and clearly belongs to this group, indicating that its distribution extends into South America.

Lasioglossum pseudotegulare is morphologically similar to the L. stictaspis complex except for its longer face (length/width ratio usually ≥ 0.83 in females and ≥ 0.86 in males), but its DNA barcodes are unique and highly divergent, and it is therefore excluded.