Coronabrotica Moura

Moura, Luciano De A., 2010, Coronabrotica, a new genus and species of Luperini, and a key to genera of Section Phyllecthrites (Coleoptera, Chrysomelidae, Galerucinae), Zootaxa 2675, pp. 26-32 : 27-30

Coronabrotica Moura , new genus

Type species: Coronabrotica amazonensis Moura sp. nov.

Diagnosis. Coronabrotica gen. nov. is the only genus of the Section Phyllecthrites that has anterior coxal cavities closed and, in males, a rounded pore on the basal half of the pronotum that is surrounded by a crown of long erect setae.

Description. Male. Body elongate oblong oval, slightly convex ( Fig. 1 ). Head with evident antennal tubercles separated by shallow suture. Eyes oval, globose. Long supraorbital bristle located close to internal ocular margin. Clypeus slightly elevated, elevation extends between antennae; space width between antennae subequal to diameter of antenna insertion.

Labrum transverse, with six long setae. Maxilla with 4-segmented palpus: palpomere I shortest and III longest, subcylindrical; sparse setae distributed throughout four palpomeres. Labial palpus with three palpomeres, palpomere II longest.

Antennae ( Fig. 4 ) with 11 segments, long, extending beyond middle of elytra ( Fig. 1 ). Scape cylindrical, slightly dilated at extremity, roughly 3.5 times length of pedicel and subequal to length of antennomere IV. Antennomere III subcylindrical, slightly shorter than IV; antennomeres IV to VII subequal, slightly dilated at apex. Antennomeres VIII to XI cylindrical, subequal in length, last with pointed apex ( Fig. 4 ).

Pronotum with deep circular depression in disc and rounded pore surrounded by crown of erect setae located on basal half close to posterior edge of disc depression ( Figs. 2, 3 ). Lateral margins well-marked, subparallel, slightly converging to anterior part of pronotum.

Prosternum with prosternal process laminar between subcontiguous coxae. Anterior coxal cavities closed. Mesosternal process subtriangular, separating middle coxae.

Elytra oblong oval, distinctively wider in apical third; apical edge subtruncate. Epipleura wider in posthumeral region, apically narrowed. Scutellum subtriangular.

Anterior legs with dilated tibiae, without apical spine; first tarsomere with ventral adhesive patch. Middle legs with notch on internal edge of tibiae, close to apex ( Fig. 5 ); apical spine present. Posterior legs with fusiform femora, thin tibiae and first tarsomere subequal in length to sum of following tarsomeres. Tarsal claws appendiculate, with subtriangular internal teeth.

Abdomen with sterna I to V subequal in length.

Aedeagus ( Figs. 7, 8 ) (= median lobe, Wilcox 1965) with median lobe (= penis, Crowson 1981) sclerotized; sides subparallel when observed ventrally ( Fig. 7 ) and slightly curved in lateral view – more accentuated curvature close to apical extremity ( Fig. 8 ); apex acuminate ( Fig. 7 ). Ostium (= apical orifice, Powell 1941; Wilcox 1965; median orifice, Sharp & Muir 1912; Shute 1983) with shapeless opening, weakly delimited. Tegmen (= spiculum, Verma 1969; basal apodeme, Munroe & Smith 1980) hastiform with basal portion inserted in basal orifice and, little below middle, bifurcated into two branches that diverge and partially involve median lobe. Two sclerites inside internal sac. Spiculum gastrale (= second spiculum, Verma 1996) constituted by two long and thin stems, forming inverted V with vertex not fused ( Figs. 7, 8 ).

Females. Shallow semicircular depression in pronotal disc. Basal half of pronotum smooth, without rounded pore surrounded by crown of erect long setae. Thin anterior tibiae, with apical spine; first tarsomere normal without ventral adhesive patch. Tibiae of middle legs without notch close to apex ( Fig. 6 ); apical spine present.

Etymology. The generic name is a composition of the word Corona , which means crown in Latin, used as a reference to the crown of setae surrounding the pore of the basal region of the pronotum in males, and of the suffix brotica, widely used in several genera of Galerucinae .

Taxonomic discussion. Coronabrotica gen. nov. has the main diagnostic characteristic of genera of Section Phyllecthrites: intermediate tibiae of males with an anteapical notch on the internal edge. Although different authors report this modification as a characteristic that defines taxa of this section (e.g. Riley et al. 2002; Gillespie et al. 2008), with the exception of Cornubrotica dilaticornis (Baly, 1879) , which also has this notch in the intermediate tibiae but is placed in the Section Diabroticites. Cornubrotica dilaticornis , as all representatives of its section, has tarsal claws bifid.

Another characteristic used to define representatives of the Section Phyllechtrites is the appendiculate tarsal claws ( Gillespie et al. 2008), which is also present in the new genus. Exceptions are found in two genera of this section: Deinocladus and Parabrotica that have bifid tarsal claws.

Although the majority of the males in the genera of the section possess some type of modification or deformation in the antennae, this characteristic is not observed in three genera: Coronabrotica , Phyllecthris and Parabrotica . The antennae of these beetles are filiform.

Similar to the pore with a crown of erect setae present in Coronabrotica , another genus of Phyllechtrites possess a modification in the pronotum of males: Oroetes has a peculiar median knob in the anterior half. In addition to these modifications, the disc of the pronotum in both genera is deeply depressed.

The exceptions observed in the sections (e.g., bifid tarsal claws and closed anterior coxal cavities in Phyllechtrites; notched tibiae in Diabroticites) may not be the only ones and call for more detailed studies, preferably cladistic, to verify if these sections constitute monophyletic groups. Gillespie et al. (2008) have reported the inconsistency in the Diabroticina sections, considering them as informal and reasonably distinct.

Regarding the male genitalia, the median lobe follows the same pattern as the one verified by Cabrera & Cabrera-Walsh (2004) in Platybrotica misionensis Cabrera & Cabrera-Walsh, 2004 and by Moura (2009) in Isotes eruptiva (Bechyné, 1956) and Paranapiacaba teinturieri (Allard, 1894) (Diabroticina) concerning the presence of a convex structure protecting the basal orifice and an acuminate apex. The hastiform tegmen also agrees with the pattern found in all Galerucinae ; that is, bifurcate, forming two divergent branches to the sides.

Figures

FIGURES 1 – 3. Coronabrotica amazonensis Moura sp. nov. 1, Habitus, male. Length = 8.3 mm. 2, head and pronotum, dorso-lateral view (white arrow, position of the pore on pronotum). 3, detail of pore with crown of setae on pronotum.

FIGURES 4 — 9. Coronabrotica amazonensis Moura sp. nov. 4, Antennae; middle legs: 5, male, 6, female; aedeagus: 7, ventral view; 8, lateral view; 9, sclerite of internal sac. Bars = 1 mm.