A key to American genus Merobruchus Bridwell (Coleoptera: Chrysomelidae: Bruchinae) with descriptions of species and two new host plant records for the subfamily

Abstract

Merobruchus Bridwell is placed in the group Merobruchus of Acanthoscelidina (Bruchini) being distinguished from all bruchines mainly by the apical projections in the last abdominal ventrite of females and some males. All 25 species of Merobruchus are distributed in the New World, mainly in the Neotropical Region, feeding on seeds of Mimosoideae (Acacieae, Ingeae and Mimoseae). As well as some other bruchine genera, Merobruchus shows considerable morphological variation both in external and in internal (male genitalia) characters. Moreover, some species are very similar to each other in their colour and distribution pattern of pubescence on the dorsal surface, sometimes making species recognition difficult. Thus, the main objective of this paper is to provide a key including coloured illustrations for Merobruchus species to facilitate the process of identification and to avoid misunderstandings. Images of dorsal habitus, male and female pygidium and male genitalia are provided for all species. In addition, M. machadoi sp. nov. (Holotype male deposited in DZUP: Brazil, Rio Grande do Sul State) is described; M. bicoloripes (Pic) and M. pickeli (Pic) are redescribed; and a new synonymy is proposed: Pseudopachymerus pickeli Pic, 1927 = Pseudopachymerus pickeli var. subnotatus Pic, 1927 syn. nov. Two new host plants are recorded for Bruchinae: Parapiptadenia rigida (Benth.) Brenan (Mimosoideae) and Pterogyne nitens Tul. (Caesalpinioideae).

Antagonistic interaction networks in a native and an exotic legume species in Colombian tropical dry forest

“…Containers were inspected every 24 h for organisms emerging from the seeds; and once emerged, they were preserved in 97% alcohol. Insects were identified to the lowest possible taxonomic level using the keys and books of Borror & White (1970), Udayagiri and Wadhi (1982), Jhonson (1990), Fernández and Sharkey (2006), Manfio and Ribeiro-Costa (2016), and with the help of parasitoid wasp taxonomist Dr. Carlos Sarmiento from Universidad Nacional de Colombia and Curculionidae taxonomist Dr. Robert Anderson from Cannadian Museum of Nature.…”

First record of the seed beetle <i>Merobruchus paquetae</i> (Chrysomelidae, Bruchinae) in the exotic tree <i>Leucaena leucocephala</i>

“…We inspected the containers twice a day, every day, and we preserved the emergent insects from the seeds in alcohol for further identification. We identified specimens belonging to Merobruchus using the keys and descriptions found in Kingsolver (1980), Kingsolver (1988), Manfio and Ribeiro-Costa (2016). We dissected the male genitalia to confirm species identity.…”