Augochlorella aurata (Smith)

Portman, Zachary M., Arduser, Mike, Lane, Ian G. & Cariveau, Daniel P., 2022, A review of the Augochloropsis (Hymenoptera, Halictidae) and keys to the shiny green Halictinae of the midwestern United States, ZooKeys 1130, pp. 103-152 : 103

Augochlorella aurata (Smith)

Diagnosis.

Augochlorella aurata is very similar to Augochlorella persimilis . Female Augochlorella aurata can be recognized by having the striations of the propodeum continuing to the posterior margin (Fig. 13C-E ), which often, but not always, is bordered by a carina (e.g., Fig. 13C ). In contrast, females of Augochlorella persimilis always have a distinct smooth portion before the margin of the propodeum (Fig. 13F-H ). In addition, female Augochlorella aurata are generally larger, have the head slightly longer and the apex of the clypeus is black only on the apical fourth (Fig. 13A ). In contrast, Augochlorella persimilis females are generally quite small, have the head slightly broader, and the apex of the clypeus is black on the apical third (Fig. 13B ).

Female Augochlorella aurata are also often confused with Augochlora pura , but Augochlorella aurata have the paraocular lobes less protuberant (Fig. 3D, F ) than Augochlora pura , and Augochlorella aurata also lack a keel on S1.

Male Augochlorella aurata can be separated from Augochlorella persimilis by the hair on the apical two-thirds of the inner edge of the hind basitarsus, which is short in Augochlorella aurata , with the length of the hairs about equal to the width of the basitarsus (Fig. 13I ), whereas Augochlorella persimilis has the hairs distinctly longer than the width of the basitarsus (Fig. 13J ). In addition, the striae on the propodeal triangle of Augochlorella aurata reach the posterior margin (as in Fig. 13C-E ) whereas male Augochlorella persimilis generally have a smooth portion before the margin.

Male Augochlorella aurata are often confused with Augochlora pura males, but Augochlorella aurata have the margin of S4 concave rather than straight, and they lack distinct punctures on the rear of the propodeum (Fig. 2D ), compared to distinctly punctured in Augochlora pura (Fig. 3B ).

Comments.

Augochlorella aurata and Augochlorella persimilis are often confused in collections and some females can intergrade to the degree where they are impossible to differentiate. Males are also frequently confused because the hind basitarsus character is often misinterpreted since both species have the basal third of the basitarsus with distinctly shorter hairs, which can cause confusion in keys that focus on the length of the basal hairs rather than the apical hairs, such as Coelho (2004), or the keys on discoverlife.org that incorrectly state that Augochlorella aurata males have the "hair on rear basitarsus all about the same length".

Given the high level of variation in Augochlorella aurata , it seems likely that it is a species complex. Supporting this hypothesis are the various forms that Ordway (1966) recognized, one of which was elevated to species rank by Coelho (2004), as well as the high barcode diversity found in the species ( Sheffield et al. 2009).

Figures

Figure 2. Characters to separate Agapostemon from Augochlorini: Complete raised carina on the rear face of the propodeum in Agapostemon A female and B male. Incomplete carina in C Augochloropsis female and D Augochlorella male E Agapostemon male hind leg with first two tarsomeres fused (red arrow pointing to point of fusion).

Figure 3. Characters to separate Augochlora and Augochlorella A S 1 of Augochlora pura female with a median keel indicated by red arrow B Augochlora pura male rear propodeum showing distinct punctures C Augochlora pura female face with protruding paraocular lobe indicated by red arrow D Augochlorella aurata female face with undeveloped paraocular lobe indicated by red arrow E Augochlora pura male face with protruding paraocular lobe indicated by red arrow F Augochlorella aurata male with undeveloped paraocular lobe indicated by red arrow. Scale bars: 1 mm.

Figure 13. Augochlorella characters A Augochlorella aurata female face B Augochlorella persimilis female face C-E Augochlorella aurata female propodeal triangles demonstrating the range of variation C apical margin carinate D apical margin largely lacking a carina E apical margin completely lacking a carina and striae partially removed from margin F-H Augochlorella persimilis female propodeal triangles demonstrating the range of variation F propodeum with narrow smooth margin G propodeum with broad smooth margin H propodeum with narrow and irregular smooth margin I Augochlorella aurata male hind basitarsus J Augochlorella persimilis male hind basitarsus. Scale bars: 1 mm (A, B); 500 µm (C-H, I, J).