Maculonomia (Maculonomia) ferruginea Engel, Tran, & Nguyen 2025, n. sp.
Creators: name: Tran, Ngat Thi
name: Phuong, Lien Thi
name: Anh, Phuong Nguyen
name: Nguyen, Anh Duc
name: Engel, Michael S.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Halictidae
Maculonomia
Maculonomia ferruginea

description: Maculonomia (Maculonomia) ferruginea Engel, Tran, & Nguyen, n. sp.
(Figs 11; 12)
urn:lsid:zoobank.org:act: AF92FDF2-A54B-4005-9048-9D295E31DD10
TYPE MATERIAL. — Holotype. Vietnam • ♀; Lao Cai, Bat Xat, Y Ty, way to the red waterfall; 21°23’03.4”N, 105°42’42.6”E; alt. 1586 m; 9.V.2019; Nguyen L.T.P., Nguyen C.Q. leg.; IEBR.
Paratypes. Vietnam • 1♀; same data as holotype; AMNH • 1♀; Lao Cai, Sa Pa, Sa Pa town, Cat Cat village; 22°19’41”N, 103°49’54”E; alt. 1264 m; 27.X.2020; Tran N.T. leg. • 1 ♀; Lao Cai, Sa Pa, Sa Pa town, Cat Cat village; 12.IX.2023; Mai T.V. leg.; IEBR.
ETYMOLOGY. — The specific epithet is the Latin adjective ferruginea, which refers to the metasomal terga with conspicuously ferruginous setae.
DIAGNOSIS. — The female of this new species is similar to the female of M. xiongjiuensis Niu & Zhu, 2017 as they have a similar body form, with black integument and lacking enameled bands on the metasomal terga apically, the mesoscutum and mesoscutellum with black setae, and the forewing with an obvious dark infumation at the apical corner. Unlike M. xiongjiuensis, metasomal T1 has faint, sparse punctures (metasomal T1 with relatively coarser, denser punctures in M. xiongjiuensis); antennal F4-F12 reddish brown (antennal F4-F12 black in M. xiongjiuensis); discs of metasomal T1-T 5 in lateral view with obvious ferruginous setae (discs of metasomal T1-T2 disc with yellowish-brown setae, T3-T5 with black setae in M. xiongjiuensis).
DESCRIPTION
Female
Measurements. Total body length 12-12.5 mm (n=4; holotype = 12.5 mm), forewing length 11- 11.5 mm (n =4; holotype = 11.5 mm).
Structure. Head broader than long, about 1.3× as broad as long (Fig. 12A); compound eyes about 1.4× genal width; mandible with short preapical tooth; supraclypeal area medially convex; clypeus convex laterally, approximately 1.5× as broad as long and apical margin straight (Fig. 12A). Mesosoma about 1.2× as long as broad; mesoscutellum round apically (Fig. 12B). Forewing with first and third submarginal cells broader than second submarginal cell, 1m-cu entering anterior apex of second marginal cell.Metabasitibial plate triangular, glabrous (Fig. 11A).
Sculpturing. Clypeus with shiny, coarse, wrinkled, dense (not contiguous) punctures; supraclypeal area with dense, contiguous punctures except punctures sparser medioapically; scape with small, sparse punctures; paraocular area with dense, coarse, wrinkled punctures of unequal sizes (Fig. 12A); frons with dense (not contiguous), round punctures; vertex with dense, wrinkled punctures except outer margin of median ocellus with shiny, impunctate, smooth area. Mesoscutum with dense, small, round punctures of unequal sizes; mesoscutellum as on mesoscutum except punctures laterally and slightly so paramedially (Fig. 12B). Anterior-facing surface of metasomal T1 with small, faint, relatively dense punctures except sparser medio-apically; disc of T1 with small, faint, sparse punctures; apical marginal zone impunctate, faintly imbricate to smooth, with a few sparse punctures scattered at base a slightly more in horizontal rows laterally (Fig. 12D). Metasomal T2-T4 with faint, relatively sparse punctures except basally with small, round, denser punctures; marginal zones of metasomal T2-T4 with small, round punctures on basal two-thirds, remainder smooth and impunctate (Fig. 12D).
Color. Body black except mandible ferruginous medially (Fig. 12A). F4-F12 reddish brown ventrally (Fig. 12A). Forewing yellow to yellowish brown, often a bit lighter apically beyond the veins, obviously dark infumate at apical corner (Fig. 11). Metasomal S2-S5 ferruginous apically.
Pubescence. Face with short, sparse, blackish setae. Setae of gena softer and denser than those on face. Pronotum basally and outer margin of pronotal lobe with dense, yellowish setae. Mesosoma dorsally and laterally with dense, blackish setae, mesoscutellum covered with dense, blackish setae; mesosoma ventrally with ferruginous setae. Propodeum laterally with tuft of long, ferruginous setae. Metafemur with ferruginous scopa. Outer surface of metatibia with dense, ferruginous, plumose setae. Outer surface of metabasitarsus with bristle-like, ferruginous setae. Inner surfaces of metatibia and metabasitarsus with short, bristle-like, bright-ferruginous setae. Anterior-facing surface of metasomal T1 and discs of T1-T 5 in lateral view with obvious ferruginous setae. Metasomal S2-S5 with bright ferruginous setae apically.
Male
Unknown.
REMARKS
At first glance the new species can easily be confused if placed among specimens of M. terminata and indeed we encountered them while entering data for M. terminata. However, the species, although seemingly cryptic, has sufficient differentiating factors to validate it as a new species.
description: Published as part of Tran, Ngat Thi, Phuong, Lien Thi, Anh, Phuong Nguyen, Nguyen, Anh Duc & Engel, Michael S., 2025, New species and records of the nomiine bee genus Maculonomia Wu, 1982 from Vietnam (Hymenoptera, Halictidae), pp. 51-73 in Zoosystema 47 (4) on pages 65-67, DOI: 10.5252/zoosystema2025v47a4, http://zenodo.org/record/14831210