Abstract The enigmatic genus Stenocrates Burmeister has 52 species that are widely distributed from Mexico to Argentina, but mainly in South America. In the present study, the larva of the third instar and pupa of Stenocrates agricola Dechambre & Hardy, 2004 are described and illustrated based on specimens from Argentina, this being the first description of immatures for the genus. The adult is also redescribed, significantly expanding the number of characters and providing information on the natural history of this species. In addition, 28 species of Cyclocephalini and 20 species of Pentodontini are morphologically compared, emphasizing the most useful larval characters used among these beetles. Stenocrates agricola shows frequent and common characters of Pentodontini species but scarce (and even absent) characters typical of Cyclocephalini species, including some considered diagnostic for this tribe. Accordingly we consider that the tribal position of Stenocrates remains controversial and more study is needed to clarify the tribal status of Stenocrates. We believe that larval morphology provides important information in systematics studies that can clarify tribal relationships within the Dynastinae.

Resumo Trichillum hirsutum Boucomont (Coleoptera: Scarabaeidae: Scarabaeinae) é redescrito porque a descrição original estava errada. Apresentam-se novos registros de distribuição no Brasil para Trichillum hirsutum Boucomont, ipselissus alvarengai Pereira and Martinez (novos registros do estado), Trichillum boucomonti Saylor, e Cryptocanthon peckorum Howden (novos registros do país).

Abstract Trichillum hirsutum Boucomont (Coleoptera: Scarabeidae: Scarabaeinae) is redescribed because of errors in the original description. New distribution records are presented for Trichillum hirsutum Boucomont, Ipselissus alvarengai Pereira and Martinez (new state records); and Trichillum boucomonti Saylor and Cryptccanthon peckorum Howden (new country records for Brazil).

Abstract Six new species of Stenocrates (Scarabaeidae: Dynastinae) are described from the Amazon Basin of Brazil: S. rionegroensis, S. varzeaensis, S. inpai, S. amazonicus, S. ariasi, and S. laceyi. The females of S. haackae Ratcliffe and S. popei Endrödi are reportd for the first time and briefly characterized. Stenocrates popei is listed from Brazil and constitutes a new country record.

Resumo É descrita uma nova espécie de Troginae — Trox juglans (Coleoptera: Scarabaeidae) da Bacia Amazônia brasileira. Foram encontradas novas localidades de distribuição para as espécies Trox fulglnosus Robinson, T. loxus Vaurie. T. punctatus Germar, T. tomentosus Robinson, e T. variolatus Melsheimer.

Abstract Trox juglans is described as new from the Amazon Basin in Brazil, and new distribution records are given for Trox fulginosus Robinson, T. loxus Vaurie, T. punctatus Germar, T. tomentosus Robinson, and T. variolatus Melsheimer.

Resumo Quatro novas espécies de Cyclocephalini (Coleoptera: Scarabaeidae) são descritas. Estas são: Aspidolea lindae, da Colômbia; Mimeoma englemani, do Panamá; Stenocrates rabbanii, do Brasil; e Stenocrates haacki, também do Brasil.

Abstract Four new species of Cyclocephalini are described. These are Aspidolea lindae from Colombia, Mimeoma englemani from Panamá, Stenocrates rabbanii from Brazil, and Stenocrates haacki, also from Brazil.