Pygidiapion De Sousa & Mermudes, a new genus of Apioninae (Brentidae Apioninae: Apionini) associated with Fabaceae from Brazil, with the description of a new species and transfer of Apion zikani Heller, 1922 Author Sousa, Wesley Oliveira De Universidade Federal de Rondonópolis, Instituto de Ciências Exatas e Naturais, Rodovia Rondonópolis-Guiratinga MT 270, Km 6, Author Mermudes, José Ricardo M. Laboratório de Entomologia, Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, A 1 - 107, text Zootaxa 2021 2021-03-23 4948 4 575 585 journal article 7456 10.11646/zootaxa.4948.4.6 c3f61d23-b35a-450c-a0c3-18c1112b9520 1175-5326 4629475 89A6F02B-DD3E-4625-8BE7-600A7841D248 Pygidiapion De Sousa & Mermudes gen. n. http://zoobank.org/ urn:lsid:zoobank.org:act: B7683E35-B4CC-44C9-A131-CCC4658FF354 ( Figs. 1–17 ) Type species: Pygidiapion zeppelinii De Sousa & Mermudes sp. n. , here designated. Etymology . The genus name refers to the remarkable male pygidium of the type species, gender masculine. Diagnosis . This new genus is distinguished from the other American genera by the following combination of male characters: rostrum ( Figs. 1, 3, 5 ) convex dorsally at prorostral level in side view, ventral surface with two elongate longitudinal and coarsely punctate sulci ( Figs. 5, 6 ); pronotum campaniform in dorsal view, slightly constricted before apex, slightly bisinuate with rounded median projection toward scutellum, without basal flange ( Figs. 1–4 ); scutellum glabrous and depressed in middle; hind wings with small radial window; hypomeral lobes divided by median suture and distinctly exposed sternellum; meso- and metatibiae mucronate; pygidium ( Figs. 10, 11 ) of the incomplete apionine type ; basal piece fused with tegminal plate ( Fig. 14 ). Description. Size: 1.70–2.20 mm . Vestiture ( Figs. 1, 2 ) in general conspicuous, with sparse and homogeneous off-white scales; meta- and mesorostrum with scales reduced, absent on prorostrum; scales of head, thorax and coxae similar in size; with centripetal vestiture on pronotum, except in posterior region where scales are perpendicular to posterior margin; denser on sides of pro-, meso- and metasternum; elytral interstriae with two or three irregular rows of scales; legs with very sparse scales; uniform on abdominal ventrites; pygidium with centripetal vestiture ( Fig. 10 ). Rostrum ( Figs. 1–7 ) cylindrical, longer than pronotum along midline; in lateral view curved, more convex at prorostral level ( Figs. 1–5 ); surface polished and finely punctate. Males with ventral surface of rostrum with longitudinal sulci punctate, squamous ( Figs. 5, 6 ). Head ( Figs. 1–4 ) with frons slightly sloped; medially glabrous with marginal scales smaller than scales around eyes; subocular keel developed, not extending to posterior margin of eyes; area between subocular keels microreticulate, impunctate. Eyes round, convex ( Figs. 1–5, 7 ). Antennae ( Fig. 5 ) inserted at basal 0.24-0.28 of rostrum length in both sexes; scape 0.65-0.90 times mesorostral width, 4.33-5.80 times as long as wide, as long as club; pedicel longer than wide, as long as desmomeres 1+2; desmomeres 2–5 times as long as wide, desmomere 6 nearly as long as wide, subconical; club oblong and compact, 2 times as long as wide, as long as last five desmomeres; sutures marked. Thorax ( Figs. 1–4 ). Pronotum campaniform in dorsal view, transverse, slightly constricted before apex, about 0.65-0.70 times as long as wide, base 1.40-1.60 times apical width, slightly bisinuate with rounded median projection toward scutellum, without basal flange; outline in lateral view slightly convex medially; pronotal disc with sub-basal fovea slightly depressed; punctures covered by scales. Procoxae contiguous, hypomeral lobes divided by median suture with sternellum distinctly exposed. Mesocoxa separated, mesosternal apophysis 1/3 as wide as mesocoxae, truncate at apex. Metacoxa transverse, metasternum narrowed, declivous anteriorly to metacoxa. Mesofemora slightly more robust than pro- and metafemora. Meso- and metatibiae mucronate. All tarsomeres 1 longer than wide, tarsomeres 2 wider than long, tarsomeres 3 bilobed; onychium 2.5 to 3.0 times longer than wide, surpassing lobes of tarsomere 3 by ca. 1/5 length of onychium. Tarsal claws toothed at base. Elytral length 1.40-1.80 times distance between humeri, convex (lateral view, Figs. 1–4 ); humeri salient, formed by glabrous basal intumescences of interstriae 6; longitudinal striae present, strongly punctate apically, at apex joining 1+9, 2, 3+4, 5+6, 7+8; interstriae 7 and 9 each with one specialized seta in apical half. Apical margin of epipleura conspicuously extended. Macropterous, hind wings with small radial window ( Fig. 9 ). Abdomen. Ventrite 1 the most elongated, impressed at disk; ventrite 2 longer than ventrites 3+4; ventrites 3 and 4 narrow; pygidium of incomplete apionine type ( Figs. 10, 11 ). Male terminalia and genitalia. Ninth sternite (spiculum gastrale) Y-shaped ( Fig. 12 ). Penis ( Fig. 13 ) impressed and curved; pedon with apical plate straight in lateral view, rounded apically in dorsal view; tectum slender and with clear margins. Tegmen ( Fig. 14 ) with tegminal plate fused to basal piece; suprafenestral plate with macrochaetae posterior to each fenestra; fenestrae and linea arquata visible. Female genitalia. Spiculum ventrale elongate and straight, apical plate membranous and setiferous ( Fig. 15 ). Ovipositor ( Fig. 16 ), coxite long with microchaetae; styli subcylindrical and with macrochaetae. Spermatheca Cshaped ( Fig. 17 ), lacking nodulus or ramus; cornu and corpus evident. Sexual dimorphism. Female differing from male in having longer and wider body; rostrum narrower and more slender ( Figs. 2, 4 ); and ventral surface at mesorostral level without ventral sulci ( Figs. 7, 8 ). Included species. Two nominal species from Brazil , one transferred from the Palearctic and Nearctic genus Apion Herbst, 1797 : Apion zikani K.M. Heller, 1922 , associated with Dalbergia foliolosa Benth. ( Fabaceae , Papilionoideae ); and one new species, Pygidiapion zeppelinii De Sousa & Mermudes sp . n . , associated with Pterocarpus violaceus ( Fabaceae , Papilionoideae ).