Mycocepurus smithii ( Forel, 1893 )

Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário & Serrão, José Eduardo, 2024, Male genitalia of the fungus-growing ants Mycocepurus goeldii (Forel, 1893) and Mycocepurus smithii (Forel, 1893) (Hymenoptera: Formicidae: Myrmicinae), Zootaxa 5471 (4), pp. 496-500 : 497-498

Mycocepurus smithii ( Forel, 1893)

Measurements. (5 measured) HW 0.77–0.82, HW2 0.53–0.57, HL 0.62–0.68, SL 0.47–0.53, MssctmL 0.58–0.68, MssctmW 0.57–0.62, Mssctm+MssctlL 0.86–0.95, WL 1.25–1.45, PetW 0.18–0.20, PpetW 0.36–0.40, GW 0.72–0.80, G1L 0.70–0.77. Pilosity and Sculpturing. Body opaque, with reticulate-punctate sculpture. Pilosity appressed. Head ( Figure 1.D ). Mandible with oblique striations on dorsal surface; masticatory margin with three teeth. Anterior margin of clypeus straight, without anteromedial notch; clypeus surface without evident median tubercles. Frontal lobes subquadrate. Frontal carina short, laterally directed. Eyes occupying at least half of the head in profile view; strongly bulging. Ocelli inserted into short, poorly developed projections. Scape reaching and exceeding the vertexal margin of the head by approximately ¼ of its length; flagellomere I 4x as long as pedicel. Occipital corners angled, forming inconspicuous teeth. Mesosoma ( Figure 1.E–F ). Pronotum with a pair of small tubercles. Notauli deep, sometimes poorly imprinted posteriorly. Scutoscutellar sulcus deep. Mesoscutelum posterior margin with a pair of two very short, blunt tubercles. Propodeum with a pair of blunt to sharp spines. Metasoma. Petiole with developed peduncle; petiolar node with the anterior portion rounded, and the posterior more straight, without projections. Postpetiole trapezoidal, wider posteriorly, in dorsal view. First tergum of gaster longer than wide. Wings ( Figure 2.B ). Heavily infuscated, covered with microtrichia. Forewing with four closed cells (basal, costal, submarginal, and marginal 1+2); semi-complete cubitus+anal vein, almost forming the subbasal cell; pterostigma inconspicuous. Hindwing without closed cell, with one single complete vein (subcostal) and two incomplete visible veins (anal and media+cubitus); 7 hamuli. Genitalia. Parameres tapering towards the apex, with blunt tips, and strongly curved internally ( Figure 2.E–F ). Digitus of volsella short, hook-shaped, internally slightly curved; cuspis not evident ( Figure 2.K ). Penisvalve with a serrated ventral margin that has nine denticles ( Figure 2.H , black triangle), its apex with a acute lobe ( Figure 2.H , red triangle), separated from the serrated margin by a deep notch; dorsomedial extension of the valviceps with a slightly conical tip ( Figure 2.H , gray triangle).

Comments. Mycocepurus smithii is easily separated from M. goeldii by different states of the following characters: body size, number of projections on the pronotum, impression of the notauli, projections of the posterior margin of the mesoscutelum, infuscation of the wings, pterostigma pigmentation, shape of the parameres, shape of the volsella digitus, number of denticles on the ventral margin of the penisvalva, and shape of the apex of the valviceps after the notch. Mycocepurus smithii , also presented variation in the number of denticles on the ventral margin of the penisvalve: although nine denticles are more commonly found, seven denticles were found in one specimen (ANTWEB1047342). The male described by Kempf (1963) as M. smithii and that was later considered as M. obsoletus ( Rabeling et al. 2009) , lacks a well-defined lobe in the apex of the valviceps ( Figure 2.I ). Furthermore, the male M. obsoletus has five denticles on the ventral margin of the penisvalve. Noteworthy that although the presence of denticles in the penisvalve seems to be common in the genus, in the parasitic species M. castrator they are absent ( Rabeling & Bacci, 2010).

Material examined. BRA: BA, Ilhéus, -14.796994, -39.043649, 10–III–1997, 5162, Ramos, L. S. (Three specimens with the following codes: ANTWEB1047310, ANTWEB1047311 and ANTWEB1047343). BRA: PA, Belém, -1.450043, -48.433290, X–2012, Barros, L. A. (Five specimens with the following codes: ANTWEB1047341, ANTWEB1047333, ANTWEB1047336, ANTWEB1047340 and ANTWEB1047342).

Figures

FIGURE 1. The male of Mycocepurus goeldii (ANTWEB1047309) and Mycocepurus smithii (ANTWEB1047342). A–C, M. goeldii male in: full face-view, profile view focus on the mesosoma, dorsal view focus on the mesonotum, respectively. D–F, M. smithii male in: full face-view, profile view focus on the mesosoma, dorsal view focus on the mesonotum, respectively. Abbreviations: Ce, compound eye; Clp, clypeus; FrC, frontal carina; FrL, frontal lobe; Lmspl, lower mesopleuron; Lmtpl, lower metapleuron; Lo, lateral ocellus; Md, mandible; Mo, median ocellus; Msnt, mesonotum; Mssctld, mesoscutellar disc; Mssctm, mesoscutum; Not, notauli; Pe, Petiole; Pl, parapsidal line; Ppd, propodeum; Prnt, pronotum; Scp, antennal scape; Sss, scutoscutellar sulcus; Umspl, upper mesopleuron; Umtpl, upper metapleuron.

FIGURE 2. Genitalia and forewings of Mycocepurus Forel, 1893 males. A, forewing of M. goeldii (ANTWEB1047309); B, forewing of M. smithii (ANTWEB10473442); C, M. goeldii genital capsule in ventral view (ANTWEB1047309); D, M. goeldii genital capsule in lateral view (ANTWEB1047309); E, M. smithii genital capsule in ventral view (ANTWEB1047343); F, M. smithii genital capsule in lateral view (ANTWEB1047343); G, penisvalve of M. goeldii (ANTWEB1047309); H, penisvalve of M. smithii (ANTWEB1047333); I, illustration of the penisvalve of M. obsoletus (based on the original drawing by Kempf, 1963); J, M. goeldii volsella (ANTWEB1047309); K, M. smithii volsella (ANTWEB1047333). Scale bar absent in I, as it was not available from the original drawing. In the penisvalves, black arrows indicate the ventral denticles of the valviceps; red arrows indicate the apex of valviceps; and white arrows indicate a dorsomedial extension of the valviceps. Abbreviations: Bs, basimere; Bsl, basal cell; C+s, costal+subcostal cell; Cu, cupula; Ds, digitus; M1+2, marginal 1+2 cell; Pt, pterostigma; S-m, submarginal cell; Te, telomere; Vc, valviceps; wings veins: cu-a, cubitus-anal.