Canthon Hoffmannsegg

Edmonds, W. D., 2018, The dung beetle fauna of the Big Bend region of Texas (Coleoptera: Scarabaeidae: Scarabaeinae), Insecta Mundi 642, pp. 1-30: 5

publication ID

http://doi.org/10.5281/zenodo.3708186

publication LSID

lsid:zoobank.org:pub:55CCB217-771C-499D-9110-36F143C375C5

DOI

http://doi.org/10.5281/zenodo.3716583

persistent identifier

http://treatment.plazi.org/id/03E087E4-FFF5-FF94-FF24-9DCBFA11F8A9

treatment provided by

Felipe

scientific name

Canthon Hoffmannsegg
status

 

Canthon Hoffmannsegg  

The genus Canthon   includes over 200 species restricted to the New World, most of which inhabit tropical South and Middle America. The United States is home to 18 species, of which 16 occur in Texas. Canthon   species are the “tumblebugs” universally familiar to naturalists, ranchers, farmers and others who have observed their remarkable habit or fashioning and rolling a ball of dung across the ground and ultimately burying it at some distance from the source. The Big Bend fauna includes four species, all widespread and closely associated with livestock and other grazing mammals, where they can be observed in large numbers jostling for position at a fresh dung pad ( Fig. 3 View Figures 1–6 ). All are dark colored, with evenly rounded bodies lacking any horns or other projections, and long, slender middle and hind legs. While they superficially closely resemble each other, the sexes can be distinguished by a combination of two external attributes: in the male, the protibial spur is bifurcate (usually asymmetrically so) and the last abdominal sternum is emarginate medially to receive the apex of the pygidium ( Fig. 27 View Figures 26–35 ); in the female, the protibial spur is acute (rounded in worn individuals) and the last abdominal sternum is not obviously emarginated medially ( Fig. 28 View Figures 26–35 ). The four Big Bend Canthon   species are easily separated by the following key.

1. Clypeus bidentate medially ( Fig. 26, 29 View Figures 26–35 ). Larger beetles, length 10–20 mm .................................................................. [Subgenus Canthon   s. str.] 2

— Clypeus quadridentate, middle two teeth larger than outer ones ( Fig. 33–34 View Figures 26–35 ). Small beetles, length ≤ 8 mm ............................................ [Subgenus Boreocanthon   ] 3

2. Black, only rarely with hint of blue reflections ( Fig. 29–30 View Figures 26–35 ). Propleuron divided by sharp, transverse carina extending from lateral margin to coxa ( Fig. 31 View Figures 26–35 , arrow).............................................................. Canthon (C.) blumei Halffter and Halffter  

— Near black but almost always with blue reflections under strong light ( Fig. 26 View Figures 26–35 ). Propleuron not divided by a carina, smooth and continuous ( Fig. 32 View Figures 26–35 )..... Canthon (C.) imitator Brown  

3. Pronotum punctate. Smaller, length 3–5 mm ............. Canthon (B.) mixtus Robinson   — Pronotum granulate. Larger, length 5–8 mm ........... Canthon (B.) praticola LeConte