Micrallo macro St Laurent & Mielke 2019, sp. n.
Creators: name: St Laurent, Ryan A.
name: Mielke, Carlos G. C.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Mimallonidae
Micrallo
Micrallo macro

description: Micrallo macro sp. n.
Figs 10, 11, 14, 16, 18
Type material. Holotype ♂. BRAZIL: Minas Gerais: BRAZIL: Minas Gerais: São Roque de Minas, São José do Barreiro, 900 m, -20.310055°, -46.540407° 16-19.XI.2017, C. Mielke leg./ St Laurent dissection: 7-21-18:6/ HOLOTYPE ♂ Micrallo macro St Laurent and C. Mielke, 2019 [red label]/ (DZUP).
Paratype. (1 ♀) BRAZIL: Minas Gerais: Data exactly as for holotype, St Laurent dissection: 7-21-18:7 (MGCL). Paratype with the following yellow label: PARATYPE ♀ Micrallo macro St Laurent and C. Mielke, 2019.
Diagnosis. In comparing the two species of Micrallo, there are several key distinctions. In terms of size, M. macro sp. n. is significantly larger than M. minutus, with a forewing length of 11.5 mm in both the male and female of M. minutus, and 15 and 16 mm in the male and female of M. macro sp. n., respectively. Sexual dimorphism in shape and size is greatly reduced in both Micrallo species relative to other Mimallonidae, but the wing shape does differ between the two species. Micrallo macro sp. n. has sharper forewing apices in both sexes, and has greatly reduced forewing discal markings than M. minutus which has more elongated, narrower, and apically blunter wings. Male genitalia of M. macro sp. n. differ from those of M. minutus by the more pronounced spine at the mesal angle of the gnathos arms in M. macro sp. n. (Fig. 14a: IV); in M. minutus this spine is reduced. In M. macro sp. n. there is a single, elongated spine on the meso-ventral portion of the gnathos arms (Fig. 14a: V) whereas in M. minutus there are two distinct spines in this region of the arms. The apices of the gnathos arms in M. macro sp. n. are broader and somewhat rectangular, these structures are more rounded and clubbed in M. minutus. Female genitalia are also distinct when comparing the two species, in M. macro sp. n. the papillae anales are elongated and narrow, whereas they are short and stout in M. minutus. The dorsal tergite VIII is less posteriorly pointed mesally in M. macro sp. n. than in M. minutus, with laterally pointed folds along the VIII segment that are absent in M. minutus.
Description. Male. Head: Light brown, eyes very large, occupying more than two thirds area of head; frons colored as for remainder of head; antenna light brown in color, but lightly covered in silvery gray scales, antenna bipectinate to tip, though distal third of pectinations much reduced in size; scape, pedicel densely clothed in gray scales; labial palpus three segmented, covered in dark brown scales dorsally and laterally, ventrally lighter brown as for head. Thorax: Light gray, lightly speckled with darker petiolate scales. Legs: Femur light brown, tarsus slightly darker brown, tibial spurs thin, longer than one-third length of first tarsal segment, tibial spurs covered in scales basally, distally glabrous. Forewing dorsum: Forewing length: 15 mm, Wingspan: 31 mm, n = 1. Triangular, narrow, barely concave below apex, somewhat convex before tornus. Ground color light silvery beige, overall lightly speckled by very dark brown petiolate scales; antemedial, medial, and submarginal areas all roughly concolours; antemedial line faint, outwardly convex; postmedial line light brown, wavy, sharply angled inward at Rs3, followed by nearly perpendicular angle toward costa where postmedial line thickens slightly and inwardly lined with darker scales, outer edge of postmedial line lined with pale scales; discal spot hardly visible but present as faint gray mark spanning distal margin of cell. Forewing ventrum: Coloration warm brown antemedially and medially, submarginally gray, antemedial line absent, postmedial line slightly dentate, outwardly convex and curved toward costa. Discal spot absent. Hindwing dorsum: Coloration as for forewing dorsum, antemedial line absent, postmedial line fainter than on forewing dorsum. Hindwing ventrum: Follows same pattern as forewing ventrum; frenulum apparently absent or vestigial. Abdomen: Coloration as for thorax but tending more toward brown than gray, very dark brown petiolate scales mostly absent. Genitalia: (Fig. 14), n = 1. Complex; vinculum irregularly shaped and deeply concave, heavily modified, variously connected to basal component of valvae, mesal base of vinculum pinched inward (Fig. 14a: I), setae covered broadened regions of vinculum present on either side of inwardly pinched region (Fig. 14a: II); pair of heavily sclerotized, curved, tusk-like arms originating near base of valvae (Fig. 14b: III), arms extend outward, crossing over each other below uncus. Tegumen narrow, rectangular, robustly sclerotized overall, especially ventrally. Uncus basally rectangular, apically narrowed. Gnathos basally fused by narrow strip of sclerotization and heavy membrane; gnathos arms outwardly sclerotized, inwardly membranous basally with upward extension of membrane forming two sacs, one on either gnathos arm; gnathos arms angled about halfway along length, with small tooth protruding outward at angle (Fig. 14a: IV), much larger tooth present more basally on internal margin of gnathos arm (Fig. 14a: V), apex of gnathos arm broadened, somewhat flattened. Valvae highly modified, membranous proximal to vinculum, narrowed distally, terminating in club-shaped lobe (Fig. 14a: VI) extending nearly to apex of uncus; base of valvae with elongate, thick, deciduous setae contained in membranous fold laterally encasing valva-vinculum complex (Fig. 14a: VII), most setae lost upon dissection. Base of vinculum associated with specialized sclerotized arms connected along membranous component of sternite VIII (Fig. 14a: VIII). Juxta partially fused to phallus, connecting base of phallus to vinculum by way of small knob. Phallus basally simple, widening distally, becoming spade-like and open dorsally from which simple vesica extends, phallus appearing “open” when viewed dorsally or ventrally; coecum phallus short, angled downward; dorsum of basal half of phallus with membranous sac running lengthwise along dorso-lateral margins (Fig. 14c: IX). Female. Head: As for male but antenna smaller overall, with shorter pectinations. Thorax: As for male. Legs: As for male, but tibial spurs thicker, more entirely covered in light brown scales. Forewing dorsum: Forewing length: 16 mm, Wingspan: 32.5 mm, n = 1. As for male but broader overall, coloration richer brown, more finely speckled with very dark brown petiolate scales, antemedial line almost nonexistent, discal spot more well-defined but still faint, present as gray oval. Forewing ventrum: As for male, but coloration richer, darker brown antemedially and medially, submarginally darker gray. Hindwing dorsum: Coloration as for forewing dorsum, antemedial line absent, postmedial line fainter than on forewing dorsum. Hindwing ventrum: As for male, but coloration richer, darker brown antemedially and medially, submarginally darker gray. Frenulum apparently absent or vestigial. Abdomen: Coloration as for thorax but deeper brown, more heavily speckled with black petiolate scales. Genitalia: (Fig. 16), n = 1. Dorsal sclerotization of tergite VIII complex, ridged, especially dorsolaterally, mesally irregularly modified. Sternite VIII as narrow sclerotized strip spanning base of ostium bursae, extending laterally to curved triangular lateral plates. Papillae anales elongated, narrow; mesally unfused collar of sclerotized plates present at base of papillae anales, plates covered by minute setae. Apophyses anteriores thin, distal third abruptly angled; apophyses posteriores robust, inwardly curved basally, distally parallel, longer than entire genitalia complex. Ductus bursae narrow, tubular. Corpus bursae bag-like, ovoid. Pair of broad lateral pouches occupying most of area of genitalia (especially when viewed dorsally), pouches connected to apophyses posteriores along their length. Right pouch (when viewed ventrally) containing few male-derived setae upon dissection, most setae lost during dissection.
Distribution. (Fig. 18) This species is so far known only from the type locality in Minas Gerais, in the Cerrado biome.
Remarks. Micrallo was described as a monotypic genus, with the type species M. minutus described from a single pair of specimens collected at one locality on the same day. Micrallo macro sp. n. is similarly described from a single pair collected on the same occasion. Now, some years after the original description of M. minutus, we can report an additional three males and one female in the collection of VOB. These four specimens are all from the same locality and date as the holotype and single paratype cited in the original description. Micrallo minutus was collected from a region where the Cerrado and Caatinga meet, so it is uncertain as to which biome this species is endemic, if it is to either one. However, with the discovery of M. macro sp. n., it is possible to hypothesize that Micrallo is a genus endemic to seasonally dry regions of central Brazil.
St Laurent and Kawahara (2019) provided apomorphies for all Mimallonidae genera. Although at the time Micrallo was only known to contain a single species, all apomorphies presented for this genus are supported by the inclusion of the newly described M. macro sp. n.. It is worth reiterating that both species of Micrallo display unique setae-pouches in both sexes. The males of Micrallo contain much more setae than the females, arranged in a somewhat ordered manner within these lateral genitalia pouches, whereas females apparently receive some of these setae in their respective pouches upon copulation. These setae in females are seemingly haphazardly stuffed into the pouches since they are readily lost upon dissection.
Etymology. This new species is named for its size, which is relatively large in comparison to its tiny congener, M. minutus.
description: Published as part of St Laurent, Ryan A. & Mielke, Carlos G. C., 2019, New species of Procinnus Herbin and Micrallo St Laurent and C. Mielke (Lepidoptera, Mimallonidae, Druenticinae) from the Brazilian Cerrado, pp. 111-124 in Zootaxa 4571 (1) on pages 117-122, DOI: 10.11646/zootaxa.4571.1.7, http://zenodo.org/record/2606050