Tomarus Erichson, 1847

Ratcliffe, Brett C., Cave, Ronald D. & Mondaca, José, 2021, The Dynastine Scarab Beetles (Coleoptera: Scarabaeidae: Dynastinae) of Chile, The Coleopterists Bulletin 75 (2), pp. 279-309 : 291-292

Genus Tomarus Erichson, 1847

Tomarus Erichson 1847: 95 .

Ligyrus Burmeister 1847: 542 (in part).

Grylius Casey 1915: 189 (synonym).

Species of Tomarus are recognized by a subtrapezoidal to subtriangular, attenuate clypeus that is bidentate and relatively narrow at the apex; frontoclypeal region with two tubercles; mandibles visible from above and with two apical teeth; pronotum with an apical tubercle and with a weak, subapical fovea in the Chilean species; and inner claw of the male protarsus simple, not enlarged.

Tomarus is comprised of 18 species that occur from southern Florida in the USA to the West Indies and Central and South America (López-García 2019). Two species occur in Chile.

Life history information for most species is fragmentary.Adults are nocturnal and attracted to lights. In general, larvae are found in soil rich in organic matter where they often feed on the roots of living plants. Some species are known to cause economic damage to crops. They have been collected from sea level to 3,640 m elevation in habitats that include temperate and tropical forests, prairies, and deserts (López-García and Deloya 2019).

Considerable reliance must be placed on the form of the male parameres for identification. The parameres are particularly fragile (almost parchment-like), and they break or tear easily. Great care should be taken when extracting the parameres from the abdomen for study.