Merobruchus pickeli
Creators: name: Manfio, Daiara
name: Ribeiro-Costa, Cibele Stramare
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Chrysomelidae
Merobruchus
Merobruchus pickeli

description: Merobruchus pIckelI (Pic, 1927)
(Figures 22, 40, 45–46, 69, 93, 119, 143)
Pseudopachymerus pickeli Pic, 1927: 32 (original description, type locality: " Brazil ", type depository: MNHN), Bondar, 1936: 26 (distribution), Kingsolver & Silva, 1991: 414 (citation).
Caryedes pickeli: Blackwelder, 1946: 758 (distribution), Udayagiri & Wadhi, 1989: 76 (catalogue).
Gibbobruchus pickeli: Zacher, 1952: 467 (host plant; questionable if related to P. pickeli Pic, 1927).
Merobruchus pickeli: Kingsolver, 1988: 2, 4, 63 (new combination, distribution, taxonomy), Kingsolver & Silva, 1991: 414 (citation), Romero-Nápoles & Johnson, 2004: 386 (distribution questionable).
Pseudopachymerus pickeli subnotatus Pic, 1927: 32 (original description, type locality: " Brazil "). New synonym.
Caryedes pickeli var. subnotata Blackwelder, 1946: 758 (distribution).
Pseudopachymerus steinbachi Pic, 1934a: 116 (synonymized by Kingsolver, 1988: 2).
Caryedes steinbachi: Blackwelder, 1946: 758 (distribution), Udayagiri & Wadhi, 1989: 77 (distribution).
Material examined. Type material. Pseudopachymerus pickeli Pic, 1927 and Pseudopachymerus pickeli var. subnotatus Pic, 1927. Holotypes deposited in MNHN, females (Fig. 156): Labels: (1) “360” (2) “ Brésil /São Bento/ (Dª B. Pickel)” [Handwritten] (3) “sementes de/Pithecolobium/ saman Benth / v.aculifolia ” [Handwritten] (4) “ Pseudopachymerus /prob stenocephalus” [Handwritten] (5) “ Pickeli n sp/et v. subnotatus/mihi” [Handwritten] (6) “ HOLOTYPE ” [Red label printed in black] (7) “ Pseudopachymerus / pickeli Pic Type /Marked +/ P. pickeli v. subnotatus /Pic/unmarked/specimen Type /J. M. Kingsolver´72” [Handwritten] (8) “ Merobruchus / pickeli (Pic, 1927) / Ribeiro-Costa, C.S. det. 2007”. Additional material. BRAZIL. 1, Chapada, Chapada Forest, May, Acc.No.2966, homotype label (USNM). Mato Grosso: 7, Cuiabá, 1987, Nonato P. & Dorval A. col., semente de sete-casca (popular name of Samanea tubulosa) (DZUP); 3, Cuiabá, 987, Nonato P. & Dorval A. col., semente de chico-magro (DZUP).
Redescription, holotype. Body length: 3.88 mm; width: 2.53 mm.
Integument. Dorsum (Fig. 22): pronotum reddish brown and dark brown; elytron bicoloured, anterior half brown and posterior half dark brown. Antenna: pale brown (Fig. 36). Ventral region: reddish brown and dark brown except anterior and middle legs pale brown (Fig. 36). Pygidium (Fig. 69): reddish brown and dark brown.
Pubescence. Dorsum (Fig. 22): pronotum pale brown and yellowish gray, pubescence denser at lateral; scutellum white; elytron variegated, pale brown, white and coppery. Ventral region: mostly white; abdominal ventrites uniformly pubescent (Fig. 36). Pygidium (Fig. 69): white and yellowish gray, homogeneous and dense, except spots with slightly sparse pubescence.
Body. Subquadrate body. Head: with occipital sulcus (Figs 2, 40); ocular index 3.06; ocular sinus 0.18 mm (Fig. 2); postocular lobe moderate (Fig. 36); frons slightly elevated, with conspicuous frontal carina, microsculptate, with regular borders, not enlarged at base (Figs 2, 40); frontoclypeal carina distinct. Antenna: serrate, antennomeres 4–10 with the same width (Fig. 36); antennomere 11 longer than wide. Pronotum: lateral margins straight in dorsal view (Fig. 22); basal lobe with straight margin; median gibbosity slightly elevated, anterior region divided by shallow longitudinal sulcus (Fig. 22); lateral gibbosities slightly elevated (Fig. 22); coarse punctation dense at disc, intermixed with fine punctation all over pronotum (Fig. 22); lateral carina absent. Scutellum: wider than long (Fig. 22), bidentate. Elytron: humeral gibbosity conspicuous (Figs 4, 22); basal gibbosity absent (Figs 45–46); striae regular in course, free apically and visibly impressed, except 4–6 formed only by isolate punctation (Fig. 45); striae 3–5 with basal denticle (Fig. 46). Mesoventrite: mesoventral process rounded apically; postmesocoxal sulcus rounded, following the curvature of the coxa (Fig. 47–48). Metaventrite: not protuberant in lateral view (Fig. 36); metanepisternum with sparse, coarse punctation; dorsal carina incomplete, not limiting posterior corner and margin. Hind leg: femur in lateral view projects beyond pygidium (Fig. 4); pecten with 4 teeth; internal margin without denticles at anterior region before pecten. Tibia, external face smooth, not microserrate; lateroventral carina complete; mucro longer than width of tibia apically; coronal tooth absent; curvature of tibia at external margin reaching half-length of tibia. Abdomen: last ventrite, median apical border with arcuate emargination, with short lateral projections (Fig. 55). Pygidium: entirely convex; median lateral tubercles slightly elevated; apical margin truncate.
Male genitalia. Median lobe (Fig. 119): length about 4 x maximum width of base of ventral valve. Ventral valve arcuate, wider than long and narrower than median lobe apically. Apical region with dense spines, short plates bi- or tridentate, sparse denticles. Median region with sparse denticles; Y-shaped sclerite with upper stem straight and lateral stems curved; four dentate sclerites with large base, two with about 2 x the size of the other. Basal region with spicules. Basal hood bilobate, wider than largest width at base of ventral valve. Tegmen (Fig. 143): lateral lobes moderately emarginate, emargination reaching slightly over half of its length; external margin straight and internal margin concave; apex truncate, oblique, convergent; with projections turned toward the ring.
Variability. Body length (n = 10): 3.37–4.15 mm; width: 2.3–2.72 mm.
Integument. Pygidium: reddish brown.
Pubescence. Dorsum: pronotum with sparse white pubescence; elytron sometimes with sparse yellowish gray pubescence. Pygidium: white.
Body. Head: ocular index 3.65–3.46; ocular sinus 0.11–0.16 mm. Hind leg: femur, pecten with 5 teeth.
Female. Abdomen: last ventrite, median apical border with arcuate emargination, with long lateral projections forming digitate process (Fig. 52). Pygidium: almost straight in female (Fig. 93).
Diagnosis. Merobruchus pickeli differs from M. bicoloripes by the antennae entirely pale brown (Fig. 36), pronotum with slightly elevated median gibbosity and with straight lateral margins (Fig. 22), elytron with a denticle at the base of the striae 3–5 (Fig. 46), the lateral lobes of the tegmen of male genitalia (Fig. 143) with an oblique and convergent apex and with projections toward the ring.
Distribution. Brazil (Mato Grosso).
Host plant. Fabaceae, Mimosoideae, Ingeae: Samanea tubulosa (Benth.) Barneby & J.W.Grimes (= Pithecellobium saman var. acutifolium Benth)
Remarks. We requested the type material of Pseudopachymerus pickeli from the MNHN and received two specimens glued on the same paper rectangle. In the original description of Pseudopachymerus pickeli, Pic also described Pseudopachymerus pickeli var. subnotatus. Next to one exemplar there is a marking red cross. This mark is also present in the upper half of a handwritten label by Kingsolver (“ Pseudopachymerus / pickeli Pic Type / marked +”; Fig. 156) showing that this is the exemplar named P. pickeli. The other exemplar, unmarked, is associated with the information in the lower half of the same label (“ P. pickeli v. subnotatus / Pic Type unmarked specimen/ J. Kingsolver 72”; Fig. 156). Both specimens differ slightly only by the pubescence colour, so the taxa are here synonymized. Romero-Nápoles & Johnson (2004) included Nicaragua as a distribution record for M. pickeli and cited Kingsolver (1988). However, Kingsolver (1988) did not deal about geographical distribution of M. pickeli, only mentioned that this species is South American. So, Nicaragua is a questionable record.
description: Published as part of Manfio, Daiara & Ribeiro-Costa, Cibele Stramare, 2016, A key to American genus Merobruchus Bridwell (Coleoptera: Chrysomelidae: Bruchinae) with descriptions of species and two new host plant records for the subfamily, pp. 284-319 in Zootaxa 4078 (1) on pages 291-292, DOI: 10.11646/zootaxa.4078.1.25, http://zenodo.org/record/263743