ABSTRACT Despite its important effect on the maintenance of tritrophic interactions among plants, insect herbivores, and ants, there is still a paucity of natural history and basic biology information involving trophobiosis among Heteroptera stink bugs. Here, based on previous observations of a new trophobiotic interaction between Edessa rufomarginata (De Geer, 1773) and Camponotus rufipes (Fabricius, 1775) ants, we describe the chemical profile of the honeydew obtained by Gas Chromatography–Mass Spectrometry. There were mainly three different sugars (trehalose, glucose, and sorbose) within our samples. The extrafloral nectaries of Caryocar brasiliense Camb., the host plant of E. rufomarginata, attracts a wide assemblage of Cerrado ants with varying aggressiveness toward herbivores. Therefore, this facultative trophobiotic interaction may allow the survival of the stink bug while feeding on the risky, highly ant-visited plant. Given the rarity of trophobiotic interactions between Pentatomidae species and ants and considering a zoological perspective within this family, here we discuss the ecological and evolutionary routes that may allow the rise of these interactions.

Revisão do gênero Antiteuchus Dallas (Heteroptera, Pentatomidae, Discocephalinae). O gênero Antiteuchus Dallas, 1851 com 46 espécies descritas é revisado; as espécies são redescritas com base na morfologia externa da genitália do macho e em algumas características da morfologia geral do corpo. Neodine Kirkaldy, 1909 é considerado sinônimo junior de Antiteuchus. As espécies foram subdivididas em seis grupos aqui propostos: A. amplus, A. supinatus, A. peruensis, A. tesselatus, A. marmoratus e A. mixtus. Oito novas espécies são descritas: A. amapensis sp. nov., A. beckerae sp. nov., A. doesburgi sp. nov., A. exiguus sp. nov., A. ledeburi sp. nov., A. marini sp. nov., A. melanicus sp. nov. and A. similis sp. nov. Nove espécies e uma subespécie são sinonimizadas. Antiteuchus varians Ruckes, 1964 é considerada sinônimo júnior de A. pallescens Stål, 1868; A. englemani Rolston, 1993 de A. amplus (Walker, 1867); A. tripterus limbativentris Ruckes, 1964 e A. minor Engleman, 1983 de A. tripterus (Fabricius, 1787); A. fuscus (Ruckes, 1959), A. piceus (Palisot de Beauvois, 1805), A. subgibbus Engleman, 1983, A. subimpunctatus Ruckes, 1964, A. unicolor (Westwood, 1837) e A. variolosus (Westwood, 1837) de A. mixtus (Fabricius, 1787). Antiteuchus tatei (Ruckes, 1958) é considerada species inquirenda. Empicoris marmoreus Spinola, 1837 é colocada em incertae sedis e tratada como species inquirenda. O macho de A. pictus, até agora desconhecido, é descrito. Chaves de identificação para os machos das espécies de Antiteuchus e para os grupos de espécies são apresentadas.

Revision of the genus Antiteuchus Dallas (Heteroptera, Pentatomidae, Discocephalinae). The genus Antiteuchus Dallas, 1851 composed of 46 species is revised. The genus and the known species are redescribed based on the male external genital structure and some external characteristics of the body. The supraspecific structure is refused and Neodine Kirkaldy, 1909 is considered synonymous of Antiteuchus. The species are split among six new groups here proposed: A. amplus, A. supinatus, A. peruensis, A. tesselatus, A. marmoratus and A. mixtus. Eight new species are described: A. amapensis sp. nov., A. beckerae sp. nov., A. doesburgi sp. nov., A. exiguus sp. nov., A. ledeburi sp. nov., A. marini sp. nov., A. melanicus sp. nov. and A. similis sp. nov. Nine species and one subspecies are synonymized. Antiteuchus varians Ruckes, 1964 is considered a junior synonym of A. pallescens Stål, 1868; A. englemani Rolston, 1993 of A. amplus (Walker, 1867); A. tripterus limbativentris Ruckes, 1964 and A. minor Engleman, 1983 of A. tripterus (Fabricius, 1787); A. fuscus (Ruckes, 1959), A. piceus (Palisot de Beauvois, 1805), A. subgibbus Engleman, 1983, A. subimpunctatus Ruckes, 1964, A. unicolor (Westwood, 1837) and A. variolosus (Westwood, 1837) of A. mixtus (Fabricius, 1787). Antiteuchus tatei (Ruckes, 1958) is considered species inquirenda. Empicoris marmoreus Spinola, 1837 is considered incertae sedis and species inquirenda. The male of A. pictus, so far unknown, is described. Identification keys for the males of the species of Antiteuchus as well as for the species groups are presented.

Revision of the genus Mecocephala Dallas, 1851 (Heteroptera, Pentatomidae). The genus Mecocephala Dallas, 1851 is revised, and some taxonomic and geographical distribution data are evaluated. The following species are considered to belong to this genus: M. acuminata Dallas, 1851 = M. holmbergi Pirán, 1969 syn. nov., M. curculionoides Pirán, 1959, M. bonariensis sp. nov., M. magna sp. nov., M. maldonadensis sp. nov., and M. zikani sp. nov.; their distribution is restricted to southern Neotropical Region. Other species, formerly placed in Mecocephala, are considered, respectively: M. rubripes Berg, 1894 incertae sedis, M. darwini Kirkaldy, 1909 incertae sedis, M. atra Bergroth, 1914 incertae sedis, Paramecocephala uruguayensis (Pirán, 1970) comb. nov., Paramecocephala fusca (Haglund, 1868) comb. nov. A key to the species is presented.

Revision of the genus Paramecocephala Benvegnú, 1968 (Heteroptera, Pentatomidae). The Neotropical genus Paramecocephala Benvegnú, 1968 is revised based on morphological characters, particularly of the genitalia of both sexes. Formerly monobasic with P. foveata Benvegnú, 1968, type species, the genus received two species recently transferred from Mecocephala Dallas, 1851: M. fusca Haglund, 1868 and M. uruguayensis Pirán, 1970. Five new species are herein described: P. australis Frey-da-Silva & Grazia sp. nov., P. bachmanni Frey-da-Silva & Grazia sp. nov., P. bergrothi Frey-da-Silva & Grazia sp. nov., P. guianensis Frey-da-Silva & Grazia sp. nov. and P. subsolana Frey-da-Silva & Grazia sp. nov. Illustrations of the genitalia, a key to the species and a distribution map are provided.