Polybia dimorpha Richards 1978
Creators: name: Amorim, Danielle C. De A.
name: Dos Santos Junior, José N. A.
name: Carvalho- Filho, Fernando Da S.
name: Silveira, Orlando T.
name: Carpenter, James M.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Eumenidae
Polybia
Polybia dimorpha

description: Polybia dimorpha Richards, 1978
(Figs 2, 10, 18, 26, 46, 47)
Polybia dimorpha Richards, 1978: 37, 40, 57. Holotype ♀, Surinam: Zanderij savannah, 3–6.viii.64, D. C. Geijskes (RMNH); examined by photographs. Carpenter 1999: 13; Rasmussen & Asenjo 2009: 48; Silva & Silveira 2009: 320.
Diagnosis. FEMALE. Fore wing with ca. 7 mm; occipital-genal margin absent dorsally from side to side, very weak laterally; gena very narrow, protuberant on the dorsolateral region; interocellar space very high; pronotal carina at sides quite distinctly marked; prominence in front of fovea strongly raised and elongated reaching the level of dorsal pronotal carina (Fig. 26); first metasomal segment with moderately wide apex, bell-shaped; body usually totally black, some specimens may have scutellum, metanotum and propodeum yellow. MALE. Unknown.
Redescription. FEMALE. Occipital-genal margin absent dorsally from side to side, very weak laterally; gena narrow and protuberant on the dorsolateral region; FHH/INTOW—0.94; malar space short; clypeus much wider than high, transverse (HCLP/WCLP—0.82) and with apex rounded; clypeus vestiture with erect yellowish bristles spaced along the apical margin of the clypeus; mandibles with similar bristles; eyes practically bare; interocellar space very high; pronotal carina quite distinctly marked at sides; prominence in front of fovea strongly raised and elongated reaching the level of dorsal pronotal carina (Fig. 26); body with few erect bristles; LMS/WMS—0.9; scrobal furrow well marked above and obliterated below; body often black, but some specimens may have yellow scutellum, metanotum and propodeum; first metasomal segment with apex wide, mostly bell–shaped, convex in lateral view; sides of tergum 1 gradually diverging; sides of the propodeum and first metasomal sternum with some erect bristles; no yellow band on the distal margin of tergum 1, and of the other metasomal terga and sterna. Proportional ratios: LSI / HMP—0.95; LSI / WT1_AP—2.0; WT1_AP / BA—2.37.
MALE. Unknown.
Nest. According to Richards (1978), some specimens came from a nest collected by M. Cooper, 1m high in a bush in a recently felled forest. The nest was 15 cm long, with an oval and elongated shape, and entrance at the center. It had some incorporated leaves at the top.
Material examined. BRAZIL: Acre, Parque Nacional do Divisor, 8°33'30”S, 72°53'30”W, 2♀ 18.iii.1997 (E. F. Morato); Amapá, Amapari–Tucano –2, 7♀ 06–07.xi.1993, 2♀ 7–9.xi.1993, 6♀ 08–10.xi.1993, 1♀ 9– 11.xi.1993, 5♀ 10–14.xi.1993 Armadilha suspensa (F. F. Ramos, W. França) (MPEG), 1♀ 06–07.xi.1993 (INPA), Serra do Navio, 2♀ 15–17.v.1989, Malaise (N. Bittencourt) (MPEG), Mun. Serra do Navio (Assentamento), 1♀ 12.x.1999 (J. Madson), Min. P. B. do Amapari, 00º51’38”S, 51º52’56”W, 1♀ 27–31.viii.2003 (J. M., J. C., E. O.) (IEPA); Amazonas, Alvarães, 2♀ 26–31.i.1994, (I. S. Gorayeb, O. T. Silveira) (MPEG), Carreiro Castanho, BR 319 km –181, 4º12’48”S, 60º49’04”W, 1♀ 15–28.viii.2016 (J. A. Rafael, F. F. Xavier), Est. BR 174 KM 115, 2♀ 16.xi.1977 (Altamiro and team), Manaus, 1 km W Taruma Falls, 1♀ 02.iii.1981 (C. young), Hwy ZF 2, Km 19.5, 02°30'S, 60°15'W, 1♀ 18.viii.1979 (Addis, Erwin, Montgomery et al.), Reserva Ducke, 1♀ 13.ix.1977, Malaise, 1♀ 27.ix.1977, Malaise, Tefé, Terra Firme, 3º25’19”S, 64º37’05”W, 1♀ 01–21.viii.2017 (J. A. Rafael, D. M. M. Mendes, J. A. Oliveira), ZF2, 2º35’21”S, 60º06’55”W, 01–15.XI.2016 (J. A. Rafael, F. F. Xavier), ZF–03 KM 23, 2º26’02”S, 59º51’15”W, 1♀ 05.i.1986, 1♀ 28.i.1986, 1♀ 6.v.1986 (Klein, Bert and team) (INPA); Maranhão, Barreirinhas Povoado das Tabocas, 03°01’S, 43°07’W, 1♀ 15.iv.2004, 1♀ 15.x.2004 (C. D. Nazaré) (MPEG); Mato Grosso, Aripuanã, Resv. Humbolt, 1♀ iii.1977 (W. L. Overal and team) (MPEG); Pará, Juruti, Pacoval, 2°34'14.2”S, 56°9'13.5”W, 1♀ 30.xi.2008, Malaise (J. Dias, S. S. Silva) (MPEG).
Distribution. Peru; Ecuador; Colombia; Suriname; Brazil: Acre *, Amazonas, Amapá *, Maranhão *, Pará*, Mato Grosso *.
Remarks. This species was described by Richards (1978) based on the female holotype from Suriname and 22 female paratypes from Suriname, Colombia, Ecuador, Peru and Brazil (AM). Such a wide distribution mostly includes Amazonian-Guyanan areas, but the Colombian record is from Barbacoas, west of the Andes and close to the Pacific coast. Richards (1978: 57) treated P. dimorpha as the first species in the subgenus Myrapetra, in a rather isolated situation, without pointing to characters to justify this except for size, “… larger and stouter than most species of the subgenus Myrapetra ”. Polybia dimorpha is indeed a little larger than most species in the occidentalis group, with a unique shape of the gena dorsally and a high pronotal prominence that is not found in other species. However, it is quite similar in characters such distribution of body bristles, and the rather elongate metasomal petiole.
description: Published as part of Amorim, Danielle C. De A., Dos Santos Junior, José N. A., Carvalho- Filho, Fernando Da S., Silveira, Orlando T. & Carpenter, James M., 2024, Taxonomic study of wasp species in the Polybia (Myrapetra) occidentalis group morphologically related to P. scrobalis and P. flavifrons, with description of a new species (Hymenoptera, Vespidae, Polistinae), pp. 537-562 in Zootaxa 5477 (5) on pages 543-545, DOI: 10.11646/zootaxa.5477.5.2, http://zenodo.org/record/12733301