Ancognatha LeConte, 1866

Sub family: Dynastinae / Tribe: Cyclocephalini / Genus: Ancognatha

Medium sized cylindrical beetles, body length 15-20mm. Body colouration shiny black to reddish brown. Commonly bicoloured, and tending towards yellow ventrally including coxae and femurs. Clypeus more strongly punctate than frons and with apex parabolic, never truncate or emarginate. Frontoclypeal suture incomplete medially. Labrum located under the clypeus, with a median rounded projection. Mentum with a deeply emarginate apex, resulting in two finger like projections. Antennae 10 segmented, with a 3 segmented club. Mandibles visible dorsally. Prosternal process present. Pronotum simply convex, without any uneveness, micropunctate, and with an apical membraneous margin. Elytra also micropunctate and without striae. Propygidium lacking stridulatory bands. Metatibia with 2 spurs, located close together. Hind tarsal claws bifid.

There are around 22 described species of Ancognatha.  A key to seventeen species is provided in Endrödi (1985).

As a member of the tribe Cyclocephalini it shares the following features:

Horns, fovea, carinae or tubercles absent. Stridulatory area on the propygidium absent. Simple mandibles that lack teeth, metatibial apex truncate and lacking teeth. Many females have an expanded elytral epipleuron near the sides of the abdomen. Males of some species with enlarged protarsal claws.

The distinct parabolic shape of the clypeus, and the deeply emarginate mentum quickly separate this species from others, particularly Cyclocephala, within the key.

A small number of Ancognatha species can have a more variable clypeal apex shape, possibly confusing it with Cyclocephala, but the mentum shape remains different. The labrum is also viewable and more prominent in Ancognatha than it is in Cyclocephala. The frontoclypeal suture is incomplete medially, whereas it is complete in most species of Cyclocephala.   

Biological information is lacking for most species. They are recorded as pests to root systems in grasslands, potatoes and vegetables. Adults are nocturnal and can be attracted to lights. Most South American species of Ancognatha are found in highland areas, where the larvae of some are fried for human consumption.

Adults of other species of Ancognatha are a common intercept of South American cut flowers into the United States.

Ancognatha is an entriely American genus with the bulk of the species present in Central and South America. One species, Ancognatha manca, is present in the USA. It is absent from Australia.

Endrödi, S. 1985. The Dynstinae of the World. W. Junk. London. 800pp.

Paucar-Cabrera, A.,  Ratcliffe, B.C. 2018. The Ancognatha Erichson (Coleoptera: Scarabaeidae: Dynastinae: Cyclocephalini) of Ecuador, with Description of a New Species. The Coleopterists Bulletin, 72(4): 665-687

Moore, M.R., Cave, R.D., Branham, M.A. 2018. Synopsis of the Cyclocephaline scarab beetles (Coleoptera, Scarabaeidae, Dynastinae). Zookeys 745: 1-99

Ratcliffe B.C. Cave R.D. 2015. Dynastinae Scarab Beetles of the West Indies. Bulletin of the University of Nebraska, Vol. 28. 346pp.

Vallejo, F., Morón, M. 2008. Description of the Immature Stages and Redescription of the Adults of Ancognatha scarabaeoides Erichson (Coleoptera: Scarabaeidae: Dynastinae), a Member of the Soil White Grub Assemblage in Colombia. The Coleopterists Bulletin, 62(1), 154-164