Mycetomoellerius janildae Santos & Chaul & Serrão 2025, sp.nov.
Creators: name: Santos, Carlos Daniel Assis Dos
name: Chaul, Júlio Cezar Mário
name: Serrão, José Eduardo
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Formicidae
Mycetomoellerius
Mycetomoellerius janildae

description: Mycetomoellerius janildae Santos, Chaul & Serrão sp.nov.
(Figs. 3–7)
Type material. Holotype: BRA: MG, Viçosa, -20.761430, -42.862560, 2019-07-25, Amaro, G. (1 worker, ANTWEB1047947) [CELC]. Paratypes: BRA: BA, Ilhéus, CEPEC - Herbário do Centro de Pesquisas do Cacau, -14.790194, -39.213208, 1986-10, Delabie, J. (1 worker, MZSPHYM0136551) [MZUSP]. BRA: MG, Viçosa, Fundos Entomologia, -20.758200, -42.867617, 2019-07-25, de Souza, D. & Chaul, J. (1 dealate queen, UFVLABECOL-005123, and five workers with the following codes: UFV-LABECOL-005124, ANTWEB1053547, ANTWEB1047925, ANTWEB1047924, and ANTWEB1053546) [CELC]. BRA: MG, Viçosa, -20.761430, - 42.862560, 2019-07-25, Amaro, G. (1 alate queen, ANTWEB1047948, and 1 alate male, ANTWEB1047950) [CELC]. BRA: MG, Viçosa, -20.761430, -42.862560, 2019-07-25, Amaro, G. (1 worker, UFV-LABECOL-011016) [CELC]. BRA: MG, Viçosa, -20.761430, -42.862560, 2019-08-25, Amaro, G. (1 worker, UFV-LABECOL-010956) [DZUP]. BRA: MG, Viçosa, Mata do Paraíso, -20.805528, -42.853417, 2016-07-12, Raimundo, A. P., Ferreira, L., Chaul, J. & Paolucci, L. (1 worker, ANTWEB1047927) [JTLC]. BRA: MG, Viçosa, Mata do Paraíso, -20.80395, -42.85510, 2021-04-17, Figueiredo, G. & Chaul J. (1 worker, ANTWEB1053564) [CASC]. BRA: MG, Viçosa, Mata São Geraldo SG, -20.816667, -42.916667, 2010-01, Audino, L. (Two workers with the following codes: ANTWEB1047928, and ANTWEB1047929) [ANTWEB 1047928 in CELC, and ANTWEB 1047929 in UFVB]. BRA: MG, Viçosa, Mata da Biologia, -20.757517, -42.865306, 2023-08-25, Figueiredo, G. & Santos, C. D. (Twelve workers in twelve pins with the following codes: ANTWEB1047926, ANTWEB1047946, ANTWEB1047554, ANTWEB1047555, ANTWEB1047556, ANTWEB1047557, ANTWEB1047558, ANTWEB1047559, ANTWEB1047560, ANTWEB1047561, ANTWEB1047562, and ANTWEB1047563) [all in CELC, except ANTWEB1047946 which is in DZUP, ANTWEB 1047554 in CPDC, ANTWEB 1047555 in PSWC, ANTWEB 1047560 in INPA, and ANTWEB 1047561 in MZUSP].
Non-type material examined. VEN: Falcón, Serranía de San Luis, 11.215858, -69.641154, 1993-08-18, Mayhé-Nunes, A. & Lattke, J. (Two workers, MZSPHYM0136549) [MZUSP]. VEN: Falcón, Serranía de San Luis, 11.215858, -69.641154, 1993-08-18, Mayhé-Nunes, A. & Lattke, J. (1 worker, MZSPHYM0136550) [MZUSP]. VEN: Falcón, Serranía de San Luis, 11.215858, -69.641154, 1993-08-18, Mayhé-Nunes, A. & Lattke, J. (Two workers, MZSPHYM0136552) [MZUSP].
Worker measurements (holotype): HL 0.81, HW 0.88, HW1 0.90, SL 0.70, PeL 0.13, An3L 0.06, MdL 0.58, MsL 1.21, PH 0.20, PL 0.34, PPH 0.27, PPL 0.25, HFL 1.13, G1L 0.95.
Measurements in mm (10 paratypes measured): HL 0.71–0.89, HW 0.75–0.90, HW1 0.83–0.93, SL 0.5–0.75, PeL 0.09–0.13, An3L 0.05–0.07, MdL 0.52–0.63, MsL 1.02–1.31, PH 0.17–0.22, PL 0.28–0.39, PPH 0.22–0.30, PPL 0.21–0.27, HFL 0.89–1.14, G1L 0.75–1.0.
Diagnosis. Body pilosity dense, with long and flexuous hairs. Lateral pronotal spines well-developed; median pronotal spines inconspicuous. Mesonotum without well-defined projections; mesopleural surface without tubercles. Frontal lobes subtriangular, with a weakly crenulate anterolateral margin; frontal carinae extending to the vertexal margin. Postocular protuberance inconspicuous; preocular carinae developed, without projections on the vertexal margin. Rounded vertexal corners, vertexal margin with shallowly median emargination. Mandibles basally with oblique striations. First gastral tergite with tubercles linked laterally and forming a pair of longitudinal marginations, and some small crenate margins in dorsal region. Worker mildly bicolored, dark brown cephalic capsule and gaster, slightly lighter brown to ferruginous appendages, mesosoma, and metasoma.
Worker description. Relatively small species for the genus standards; without strong polymorphism. Dense setae covering the body, larger setae on dorsum of head, small subdecumbent setae on antennomeres, mesosoma and metasoma flexuous, those on legs suberect. Integument dull; mildly bicolored: most of the body light brown to ferruginous, head and gaster dark brown. Head. Eye weakly convex, not fully surpassing head lateral margin. Mandibles shiny, except for oblique striation at base; masticatory margin with a total of nine teeth: a large apical tooth, an intermediate-sized subapical, followed by six, subequall and small teeth and a large basal tooth. Anterior clypeal margin with a median notch about as wide as the maximum scape width. Frontal lobes subtriangular, with mildly crenulate anterolateral margin; frontal carinae extending to the vertexal margin. Frons shallowly concave. Vertexal carinae parallel, poorly-defined. Preocular carinae reaching the vertexal margin, but not surpassing it as a projection in full-face view; postocular carinae inconspicuous, postocular protuberance tiny. Vertexal corners rounded, vertexal margin with shallowly median emargination. In profile view, posterior section of ventral margin of head with a feeble carinae, without protuberances. Antennal scape maximum width just posterior to midlength, with small piligerous tubercles, exceeding the vertexal margin by a little less than its maximum width when retracted;
totaling eleven antennomeres. Mesosoma. Pronotal medial pair of spines absent or reduced, when present without fused bases; pronotum with a pair of well-developed anterolateral spines, sometimes with truncate tips. Mesonotum without projections, except for a few piligerous minute tubercles; mesopleural surface without tubercles. Metanotal suture shallow and wide. Propodeum dorsum bordered laterally by piligerous tubercles; pair of propodeal spines posterolaterally directed, slightly longer than the distance between their internal bases; propodeal spiracle projected from surrounding surface, posteriorly directed. Metasoma. In dorsal view, petiolar node subquadrate; postpetiole wider than long. Anterior subpetiolar and subpostpetiolar processes small. Petiolar node, postpetiole tergite and first gastral tergite unevenly covered with pilligerous tubercles; on first gastral tergite the tubercles are linked laterally and form a pair of longitudinal marginations, forming carinae, and some small tubercles forming interconnected carinae in dorsal region.
Queen measurements (2 measured): HL 0.91–1.04, HW 0.92–1.17, HW1 0.93–1.17, MoW 0.05–0.07, MoL 0.04–0.04, LoL 0.05–0.05, LoD 0.27–0.29, SL 0.63–0.68, PeL 0.11–0.13, An3L 0.08–0.10, MdL 0.71–0.72, MsL 1.49–1.72, MssctmW 0.82–0.95, MssctmL 0.70–0.82, MssctlL 0.26–0.33,MssctmL + MssctlL 1.10–1.28, PH 0.28– 0.30, PL 0.41–0.53, PPH 0.37–0.44, PPL 0.28–0.28, HFL 1.32–1.38, G1L 1.42–1.62.
Queen description. Similar to worker, except for the caste differences such as presence of ocelli, mesosoma with a well-developed mesonotum, and wings. Ocelli similar-sized. Pronotum with a pair of robust blunt anterolateral projections. In dorsal view, mesoscutum and mesoscutelum with abundant piligerous tubercles. Scutoscutellar suture broad and shallow; mesoscutellum posterior margin with a pair of robust projections. Propodeal spines with robust bases. Wings. Slightly infuscated; covered with microtrichia; forewing with eight closed cells (basal, costal+subcostal, discal 2+3, marginal 1+2, subbasal, subdiscal, submarginal 1, and submarginal 3+4); pterostigma slightly pigmented.
Male measurements (1 measured): HL 0.61, HW 0.65, HW1 0.73, EL 0.28, EW 0.20, IOD 0.48, OOD 0.22, MoW 0.05, MoL 0.04, LoL 0.06, LoD 0.23, SL 0.68, PeL 0.11, An3L 0.08, MdL 0.40, MsL 1.43, MssctmW 0.72, MssctmL 0.73, MssctlL 0.25, MssctmL + MssctlL 1.04, PH 0.18, PL 0.36, PPH 0.24, PPL 0.19, HFL 1.60, G1L 0.8.
Male diagnosis. Frontal carinae extending beyond the posterior level of the eyes, reaching lateral ocelli. Preocular carinae well-developed, slightly converging apically and reaching the lateral ocelli. Lateral pronotal projections very short, with relatively wide bases. Propodeal projections short and blunt, twice as long as those of pronotum. Notauli narrow, strongly impressed anteriorly, and slightly posteriorly, forming a ‘Y’; mesoscutellum as wide as long, with a pair of tiny blunt projections on the posterior edge. Mandible triangular; reticulate-punctate at basal half, apical half smooth; masticatory margin with six teeth, basal and apical larger than the others, with the remaining teeth unequally spaced. Anterior clypeal margin mildly bilobed. Pilosity dense, with ferruginous to dark brown setae all over the body, most strongly curved, but sometimes suberect. Penisvalva ventral margin with about 20 sharp, minute denticles; apex of valviceps round. Body dark brown, except for legs, mandibles, antennae and posterior portion of gaster (from abdominal segment V backward) which are light brown.
Male description. Overall reticulate-punctate sculpturing. Pilosity dense, with ferruginous to dark brown setae all over the body, most strongly curved, but sometimes suberect. Head. Mandible triangular; reticulate-punctate at basal half, apical half smooth; masticatory margin with six teeth, basal and apical larger than the others, with the remaining teeth unequally spaced; basal margin fit tightly again anterior clypeal margin when mandible is closed; outer margin slightly sinuous. Anterior clypeal margin mildly bilobed. Frontal lobes subcircular and poorly developed, only partially covering the scape bulbus; frontal carinae extending beyond the posterior level of the eyes, touching lateral ocelli. Frons rugulose. Preocular carinae well-developed, curving slightly at apex touching the lateral ocelli. Antennal scape in rest position exceeding the posterior margin of the head by the length of antennomeres I and II combined, remaining twelve antennomeres slightly longer than wide, the last three being more robust than the others. Bulging eyes. Mesosoma. Lateral pronotal projections small, with a relatively wide base. Wide sulci between upper mesopleura and lower mesopleura, and between upper mesopleura and upper metapleura. Propodeal projections short and blunt, twice as long as those of pronotum. Notauli narrow, strongly impressed anteriorly, and slightly posteriorly, forming a ‘Y’. Mesoscutum wider posteriorly than anteriorly, scutuscutellar sulcus broad and shallow. Mesoscutellum as wide as long, with a pair of tiny blunt projections on the posterior edge. Metasoma. Petiole, in dorsal view, subquadrate, with a pair of pointed projections posterolaterally. Postpetiole with a posteromedial shallow concavity. First tergum of the gaster longer than wide. Wings. Infuscated; covered with microtrichia; forewing with eight closed cells (basal, costal+subcostal, discal 2+3, marginal 1+2, subbasal, subdiscal, submarginal 1, and submarginal 3+4), with the medial (M) and cubital (Cu) veins less proeminent at apex; pterostigma slightly pigmented. Genitalia. Sternite IX distal margin round. Telomeres strongly curved internally, narrowing apically, with round apexes. Volsella digitus spatular (wider apically), mildly curved internally; cuspis forming a rounded lobe. Ventral margin of penisvalva with about 20 minute denticles; valviceps apex round.
Geographic distribution. Brazil (Bahia, Minas Gerais, Rio de Janeiro, and São Paulo), Panama, and Venezuela.
Comments. Mycetomoellerius janildae is similar to M. relictus, and some records of the latter could be of M. janildae. Mycetomoellerius relictus worker differs by the following characters: median pronotal spines present and not basally fused, vertexal margins angled, mesonotal projections blunt if present, abundant setae but that are shorter than those of M. janildae. Males of M. janildae and M. relictus are relatively similar, sharing the small lateral pronotal projections, narrow notauli, mesoscutellum with a pair of tiny blunt projections on the posterior edge, and propodeal spines short and blunt (Fig. 9). However, upon examining the genitalia differences can be observed, for example, the penisvalva of M. relictus has larger teeth on its ventral margin (Fig. 9, H), but smaller numbers than that of M. janildae (Fig. 9, G). Furthermore, a slight difference was observed in the shape of the apex of the penisvalva between the species, being more rounded in the case of M. janildae than in M. relictus. Despite these differences, both penisvalva follow a simple morphological pattern within Formicidae (Snodgrass, 1941), without major variations such as those observed in males of Apterostigma and Mycocepurus, which present notches and projections in certain regions of the penisvalva, in addition to a significant variation in the shape of its apex (Santos et al., 2024). Related to the volsella of males, a pattern common to species of the genus was observed, with the digitus internally curved and spatulate, with a slight difference in the cuspis lobe position.
Etymology. Named in honor of Janilda Aparecida Assis dos Santos, the mother of the first author. The name is formed by the addition of the singular Latin genitive case suffix -ae to the first name of a female person; the orthography of an eponym is unchangeable and is not dependent on the generic name in which the epithet is applied.
Biology. The entrance to the underground nest is approximately 4 mm in diameter at the base and is situated at the bottom of a small mound of moist soil, measuring approximately 1.5 cm in height. A chamber was found at a depth of 15–20 cm, containing 12 workers and a small fungal garden, but no queens. Despite further excavation, no additional chambers were located, though deeper chambers may exist. Workers have been observed to transport frass and fragments of flowers, which are likely to be used to cultivate their symbiotic fungus. The fungus displayed a spongy texture and a yellowish hue.
description: Published as part of Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário & Serrão, José Eduardo, 2025, Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus, pp. 93-118 in Zootaxa 5569 (1) on pages 99-105, DOI: 10.11646/zootaxa.5569.1.3, http://zenodo.org/record/14703972