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1 September 2014 A New Species of Gibbobruchus from Brazil, with New Host Plant and Distribution Records for the Genus (Coleoptera: Chrysomelidae: Bruchinae)
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Abstract

Gibbobruchus bergamini Manfio & Ribeiro-Costa sp. nov. (Coleoptera, Chrysomelidae, Bruchinae) is described from Brazil (state of Goiás) and it is here included in an updated key to the Gibbobruchus Pic species. The dorsal aspect, male and female pygidium and male genitalia are illustrated. This new species develops in seeds of 6 Bauhinia L. (Fabales: Fabaceae: Caesalpinioideae) species. New host plant records for other 4 species of Gibbobruchus are presented. Considering the host plants of G. bergamini sp. nov., a total of eleven new hosts are added to the genus; with exception of Phanera Lour. (Fabales:Fabaceae)- which we recorded the first time for Gibbobruchus, all Gibbobruchus spp. were collected in Bauhinia seeds. Geographic distribution data and further comments on host plant associations are also included.

Gibbobruchus Pic is placed in the subtribe Acanthoscelidina of Bruchini that comprises about half of all bruchines and has no precise limits (Silva & Ribeiro-Costa 2008). Recently, a cladistic study of Gibbobruchus was developed (Manfio et al. 2013) to improve the understanding of this subtribe and specially to the group Merobruchus where Gibbobruchus is included with more 6 genera (Silva & Ribeiro-Costa 2008). Manfio et al. (2013) synonymized 2 species names described other 2 new species, resulting in 13 valid species The phylogenetic analysis recovered Gibbobruchus as a monophyletic group supported by 7 synapomorphies and composed of 5 monophyletic species groups. It occurs in the Nearctic and Neotropical regions, from the USA (Washington State) to Argentina (Buenos Aires Province), but more than a half of the species are exclusive to South America. Species with known host associations feed within seeds of Bauhinia L. (Fabales: Fabaceae: Caesalpinioideae: Cercideae), although there is a shift to the closely related genus Cercis L. (Fabales: Fabaceae: Caesalpinioideae: Cercideae) in the Nearctic region.

In our quest to elucidate the South American fauna of the Bruchinae, we collected specimens in savannah areas from Central Brazil, State of Goiás. The results presented in this paper include the recognition of an additional Gibbobruchus species from savannah, which brings the total to 14 species of Gibbobruchus, new host plant records for 4 described species placed in 2 different species groups and new geographic distribution records. Here we also record for the first time Phanera Lour. (Fabaceae: Caesalpinioideae: Cercideae) as a host of Gibbobruchus and provide an updated key to this genus.

Material and Methods

Previously collected data were obtained from Manfio et al. (2013) and new specimens were obtained from mature pods of many Bauhinia species collected in several localities in the State of Goiás, Brazil, between 2009 and 2012. The fruits were stored in plastic bottles at room temperature for at least 2 months. The bottles were observed weekly and adults that emerged from seeds/pods were collected and stored in 70% alcohol. All specimens were sent to the Laboratório de Sistemática e Bioecologia de Coleoptera of the Universidade Federal do Paraná for identification by the first and second author.

The methods used for morphological study of the new species are those of Manfio et al. (2013), including the terminology for the male genitalia that was the same as that of Kingsolver (1970), except the subretangular, shallow structures on the median region of the median lobe here illustrated. For the type label data, quotation marks (“ ”) separate different labels and slashes (/) separates different lines in the same label. Text within square brackets [ ] is explanatory and was not included in the original labels.

The type specimens are deposited in the following collections: CEAM-Centro de Entomologica y Acarologia, Montecillo, Mexico (J. R. Nápoles); DZUP-Coleção de Entomologia Pe. J. S. Moure, Curitiba, Paraná, Brazil (C. S. Ribeiro-Costa); FSCA-Florida State Collection of Arthropods, Gainesville, Florida, United States of America (M. C. Thomas); MNRJ-Museu Nacional/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil (M. A. Monné); MZSPMuseu de Zoologia, Universidade de São Paulo, São Paulo, Brazil (S. Casari); TAMU-Texas A & M University, College Station, Texas, United States of America (E. Riley); USNM-National Museum of Natural History, Washington, D. C., United States of America (A. Konstantinov). All specimens of the sections “New host plants” and “New distribution records” for Gibbobruchus” are deposited in DZUP. The new host plants, Bauhinia mollis (Bong.) D. Dietr., B. curvula Benth., B. brevipes Vogel, B. vespertilio S. Moore, B. pentandra Bong. (Steud.), B. rufa (Bong.) Steud, B. ungulate L., Phanera sp., were identified by the third author with the use of specific keys (Vaz 2003; Vaz et al. 2010) and are deposited in the Herbarium of the Universidade Federal de Goiás.

All botanical names of the plants were checked using the International Legume Database & Information Service (ILDIS) (  http://www.ildis.org/LegumeWeb).

The host plants records recognized for the first time for the genus Gibbobruchus and the geographic distributional (to the state level) recognized for the first time for the species are marked with an asterisk (*).

Colored versions of the Figs. 18 can be seen online in Florida Entomologist 97(3) (September 2014) at  http://purl.fcla.edu/fcla/entomologist/browse.

Gibbobruchus bergamini Manfio & Ribeiro-Costa sp. nov.
(Figs. 18)

  • Diagnosis

    This species is probably closer to species of the group scurra as G. cavillator (Fåhraeus, 1839), G. bolivianus (Manfio & Ribeiro-Costa 2013) and G. scurra (Boheman, 1833), which is supported by the following synapomorphies (Manfio et al. 2013): alutaceous female pygidial speculum (Fig. 5) and lateral apical margin of the pronotum concave (Figs. 1 and 2). Gibbobruchus bergamini Manfio & Ribeiro-Costa sp. nov. has external morphology very similar to G. cavillator and G. bolivianus, sharing mainly the vestiture on dorsum, the female pygidium and the ventral region (Manfio et al. 2013). Only the male can be distinguished based on characters of internal sac of male genitalia, such as the apical region with dense small and thin spines near the valves forming lateral and median lines and median region with subretangular, shallow structures and sparse thick spines and denticles (Fig. 7). For details about the morphology of G. cavillator and G. bolivianus see Manfio et al. (2013).

  • Description

    Body length: 2.1–3.3 mm; body width: 1.4–2.5 mm.

    Integument. Color usually different between sexes: male light brown to brown with variegated pattern (Fig. 1) and female dark brown to black (Fig. 2). Antenna light brown to dark brown, darkened antennomeres varying in position (Figs. 1–3). Pygidium of female black, sometimes rufous, except on speculum (Fig. 5) and of male brown to dark brown (Fig. 6). Ventral region dark brown to black, rarely rufous (Fig. 3). Anterior and middle femur and tibiae bicolor; dorsal half of hind femur sometimes lighter than the ventral half (Fig. 3).

    Pubescence. Dorsum variegated; male usually white, light brown, brown and dark brown, with denser setae than female (Fig. 1); female in general white, brown and dark brown setae (Fig. 2). Pronotum at basal region and median gibbosity usually with dense white or light brown pubescence; median gibbosity with 2 subparallel, narrow, brown or dark brown strips anterior and posterior to median transverse sulcus (Figs. 1, 2). Scutellum light brown to brown, sometimes white (Figs. 1 and 2). Elytron with median, slightly curved, dark brown to black ma