Austrothurgus cognatus (Smith) Gonzalez & Engel & Griswold, 2013

Gonzalez, Victor H., Engel, Michael S. & Griswold, Terry L., 2013, The lithurgine bees of Australia (Hymenoptera: Megachilidae), with a note on Megachile rotundipennis, Journal of Melittology 2013 (11), pp. 1-19 : 5

Austrothurgus cognatus (Smith) , new combination

( Figs. 6–10 )

Lithurgus cognatus Smith, 1868: 255 . Lectotype (new designation): NHML No. 17.a.2099; ♀, Champion Bay (Geraldton), Western Australia, Australia.

DIAGNOSIS: The female of this species is similar to that of A. rubricatus in the sternal scopa and fifth and sixth terga with distal margins entirely covered with yellowish to light reddish brown setae ( Fig. 6 ). It can be distinguished from that species by the following combination of characters: large bees (head width 4.8‒5.1 mm, body length 16‒17 mm); clypeus smooth, shiny, distinctly swollen laterally along epistomal sulcus ( Figs. 6–8 ); vertex with large impunctate areas ( Fig. 9 ); facial prominence with deep median emargination, appearing bilobed in dorsal view, projecting about 0.7 times width of compound eye in profile ( Figs. 6–8 ); and mesoscutum and mesoscutellum smooth and shiny, with distinct transverse, irregular rugulae. The male also resembles that of A. rubricatus in the distal terga with light reddish brown setae on their discs contrasting with the remaining terga covered by dark brown to black setae. However, in A. cognatus the metabasitarsal carina is long, about as long as the distance from its superior margin to the base of the metabasitarsus ( Fig. 10 ), whereas in A. rubricatus the metabasitarsal carina is much shorter than the distance between its superior margin and the base of the metabasitarsus ( Fig. 5 ).

COMMENTS: This species was described based on both sexes. The female is more distinctive than the male and herein is designated as lectotype to stabilize the name. The label data for this specimen are as follow: Type // BM. TYPE HYM. 17.a.2099// Lithurgus cognatus Smith [handwritten, blue label] // W. Australia // Lectotype, Lithurgus cognatus Smith des. V.H. Gonzalez, M.S. Engel & T. Griswold ♀.

Figures

Figures 6–10. Photomicrographs of lectotype female (6–9) and male (10) of Austrothurgus cognatus (Smith). 6. Lateral habitus. 7. Facial view. 8. Lateral view of head. 7. Detail of vertex. 10. Male metatarsus (apex missing), depicting modification of metabasitarsus.

Figures 1–5. Photomicrographs of lectotype female (1–4) and male (5) of Austrothurgus rubricatus (Smith). 1. Lateral habitus. 2. Dorsal habitus. 3. Lateral view of head. 4. Facial view. 5. Male metatarsus, depicting modification of metabasitarsus.