A phylogenetic review of the genus Heraeus (Rhyparochromidae, Myodochini)

DELLAPÉ, P.M.; MELO, M.C.

Buenos Aires

Otro; VII Reunión Argentina de Cladística y Biogeografía; 2007

Instituto Darwinion

The Rhyparochromidae contains two subfamilies, the Plinthisinae with only one tribe: Plinthisini; and the Rhyparochrominae including 14 tribes (Henry 1997). All of these, except Cleradini (some of whose members are blood-feeding), are phytophagous; mostly feeding on Poaceae seeds. The Myodochini are abundant in all major zoogeographical regions, sometimes reaching high latitudes in temperate areas, some species appear to be extremely vagile, and there has been colonization of many oceanic islands (Schuh & Slater 1995). The Neotropical fauna of Myodochini is particularly diverse, Slater (1986) mentioned that the Neotropical fauna of Rhyparochromidae is the most disharmonic of any of the major fauna regions, consisting almost entirely of Myodochini, Lethaeini, Ozophorini, Antillocorini, and a few Udeocorini and Plinthisini. He noted that the absence of many Old World tribes appears to have permitted the radiation and diversification of the Myodochini. This tribe, with 68 genera and more than 300 species, is the most diverse group of rhyparochromids in the Neotropics with 24 genera and more than 70 species described. Stål (1862) in his Hemiptera mexicana erected the genus Heraeus to include Lygaeus (Plociomerus) triguttatus Guerin-Meneville and mentioned its affinity with the genus Myodocha Latreille. Harrington (1980), in her review of the Myodochini of the world, and Slater & Baranowski (1990) in Lygaeidae of Florida give a diagnosis of the genus, and mentioned the distinctive pronotal collar extending forward beneath the head ventrally, a synapomorphy of this genus. In the cladistic analysis presented by Harrington (1980) Heraeus is closely related to Myodocha, Orthaea Dallas and Catenes Distant by the distinctly elongate head. Up to now the genus Heraeus includes 13 species found in the Western Hemisphere and the West Indies; three of them (H. cinnamomeus Barber, H. coquilletti Barber, H. plebejus Stål) from the Nearctic region, eight (H. cincticornis Stål, H. caliginosus Slater & Baranowski, H. concolor Slater & Baranowski, H. elegans Walker, H. guttatus (Dallas), H. illitus Distant, H. pacificus Barber, H. pulchellus Barber) from the Neotropical region, and two (H. eximius Distant, H. triguttatus (Guerin)) are mainly tropical elements distributed in both regions. The material examined belongs to the collections of California Academy of Sciences, San Francisco, USA (CAS), Museo Argentino de Ciencias Naturales, Argentina (MACN), Museo de Ciencias Naturales de La Plata, Buenos Aires, Argentina (MLP), and Ohio State University, Columbus, USA (OSU). Additional material was collected by the authors in Iberá Reserve, Colonia C. Pellegrini (28º32’S, 57º11’W) and in Santa María Reserve, Ituzaingó, (27º35’S, 56º42’W) Corrientes, Argentina. The maps were done using the program DIVA-GIS (Hijmans et al. 2005) including specimens and literature data; some localities were geo-referenced using this program. To carry out the phylogenetic analysis a data matrix of 22 taxa and 25 morphological characters was analyzed; after Harrington’s (1980) cladistic analysis of the Myodochini of the world, the type species of the genera Catenes, Orthaea, and Myodocha were selected as outgroups. Characters and character states were based on direct observation of the studied material, and in some cases on the original descriptions. The analysis was performed using the program TNT (Goloboff et al. 2003), where a heuristic search for the most parsimonious trees was applied. In this contribution we describe seven new species, one from the Nearctic and six from the Neotropical region and Heraeus cincticornis Stål is consider a junior synonym of H. elegans. In addition, the morphological analysis conducted in this study plus the support of results from the cladistic analysis showed that external morphological characters and male genitalia justify the creation of a new genus for H. eximius Distant.and another to include H. elegans Walker. Therefore, Genus. A and Genus. B are proposed and the new combinations are established.