Augyles auromicans (Kiesenwetter), 2012

King, Jonas G. & Lago, Paul K., 2012, The variegated mud-loving beetles (Coleoptera: Heteroceridae) of Mississippi and Alabama, with discussion and keys to the species occurring in the southeastern United States, Insecta Mundi 2012 (275), pp. 1-53 : 29

17. Augyles auromicans (Kiesenwetter)

New Combination

( Fig. 30 , 51 , 70 )

Heterocerus auromicans Kiesenwetter 1851: 287 .

Centuriatus auromicans (Kiesenwetter) : Pacheco 1964: 30.

Description. Length 3.5 - 5.5 mm. Reddish-brown. Pronotal disk with a pale midline, about one-eighth the width of the pronotum ( Fig. 30 ). Elytra trifasciate; pale elytral markings orange and distinct. Postmetathoracic coxal lines and post-mesothoracic coxal lines prominent. Male genitalia ( Fig. 51 ) of the typical Augyles type; phallobase slightly expanded anteriorly; medial edges of caliper-like parameres separated by an ovoid space; a dark, membranous internal structure (presumably the aedeagus) is often curled within the anterior end. Hypermandibulate males unknown.

Diagnosis. The presence of post-metathoracic coxal lines and a median pale stripe on the pronotum make this species easy to distinguished from all other southeastern heterocerids.

Notes. Aggregations of A. auromicans form mud galleries that are smaller and more scattered than those made by H. pallidus ( Kaufmann 1987) . This apparently leads to less frequent mating encounters, and consequently, male priority (the last male to mate with a female fertilizes nearly all of the eggs). Spermatogenesis is constant in A. auromicans , in contrast to H. pallidus where spermatogenesis is affected by weather patterns. Augyles auromicans also flies less often as a response to agitation than H. pallidus , usually choosing to dig deeper into the substrate rather than taking flight ( Kaufmann 1987).

The species has not been found in Mississippi, and only one specimen is known from Alabama. This specimen was collected from a swampy area near Tuscaloosa (Tuscaloosa County, 5 mi. SW Tuscaloosa, 18 April 1981, S.C. Harris), which has since undergone development.

Distribution. Augyles auromicans occurs from southern British Columbia southeast to Colorado and east throughout the northern United States to the Atlantic Coast. Records from the northern U.S. and southern Canada are common; however, A. auromicans has rarely been collected in the southern states ( Fig. 70 ).

Specimens examined. 8 (See Appendix).

Figures

Figures 30-31. Habiti of two widespread species reported to occur in the southeastern USA. 30) Augyles auromicans. 31) Heterocerus fenestratus. Scale line = 1mm.

Figures 45-53. Male genitalia of southeastern species. The ventral view is shown unless otherwise stated. 45-50) Heterocerus species in the undulatus group. 45) H. undatus. 46) H. collaris. 47) H. texanus; left - ventral view, right - lateral view. 48) H. schwarzi; left - ventral view, right - lateral view. 49) H. tenuis. 50) H. selanderi. 51-53) Augyles and Tropicus species. Figures 52-53 are at roughly 2x relative scale of prior genitalia. 51) Augyles auromicans. 52) Tropicus nigrellus; left - dorsal view, center - ventral view, right - lateral view. 53) Tropicus pusillus; left - dorsal view, right - ventral view.

Figure 66-72. Distribution by county in the United States. 66) Heterocerus undatus. 67) Heterocerus texanus. 68) Heterocerus schwarzi. 69) Heterocerus tenuis. 70) Augyles auromicans. 71) Tropicus pusillus. 72) Tropicus nigrellus.