Microbrachida Bierig 1939
Creators: name: Caron, Edilson
name: Souza, Maria Geralda De
name: Pamblona, Ana Maria Santa Rosa
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Microbrachida

description: Microbrachida Bierig, 1939
(Figs 1–22)
Type species. Microbrachida gilvicornis Bierig, 1939 (designated by monotypy).
Diagnosis. Microbrachida differs from Brachida and Probrachida by having body sublimuloid in dorsal view (Figs 1, 6); head strongly deflected (Figs 2, 7); labium without medial seta (Fig. 10).
Description (based mainly on M. perniciosae). Adult. Male. Maximum body length 1.5 mm, maximum elytral width 0.5 mm; Body sublimuloid, apex of elytra widest and abdomen tapering toward the apex (Figs 1, 6). Body sublimuloid, with somewhat pubescence, surface sculpture reticulates throughout. Head transverse, slightly wider than long; strongly deflected (Figs 2, 7); base hidden in dorsal aspect by anterior margin of pronotum; medial and lateral macrosetae absent; eyes very large, globose, prominent, coarsely faceted, extended most length of lateral margin of head; temple obsolete; infraorbital carina well developed and complete; neck carina well developed. Antenna short, reaching base of pronotum (Fig. 1); scape, pedicel and antennomeres 3 and 4 subglabrous and coarse pubescence internally directed (Fig. 18); fine pubescence increasing gradually on antennomeres 5 to 11, each with coarse pubescence on apical region; scape, pedicel and antennomere 3 each two times longer than wide; scape and pedicel with the same width and wider than antennomere 3; antennomere 4 shortest, transverse, slightly wider than the precedent; antennomeres 5 to 10 transverse, increasing in width toward the apex; antennomeres 11 longer than wide and slightly wider than antennomere 10. Labrum transverse, broadly emarginated on apical margin (Fig. 8); pair of membranous lobe well developed; α-sensillum (a-sensillum of Sawada 1972) well developed, filiform; β-sensillum (b-sensillum of Sawada 1972) very short; ε-sensillum setose and shorter than labral setae; A.L. 1 (d1 of Sawada 1972) distant from margin of labrum and A.L. 2 (d2 of Sawada 1972) at margin of labrum; each lateral margin with three spine-like sensilla, distant from lateral margin; internal setose area absent. Mandibles asymmetrical, not bifid at apex; right with moderalely internal tooh; prostheca with finely ciliate; molar region with rows of small denticles. Maxilla with apex of lacinia obliquely truncate, with patch of numerous closely spaced teeth (spore brush of Ashe 1984) (Fig. 9); setae on inner surface of lacinia in single irregular row; galea with apical setae in numerous close rows, setae filiform; palpomere 1 shortest, 2 and 3 about the same length, 4 about two-thirds length of precedent. Labium with mentum somewhat trapezoidal, twice wider than the maximum length (Fig. 107 ligula entire, broadly rounded; medial seta absent; labial palpi two-articled (1 and 2 fused), 3 about one-third length of precedent. Gular plate broad, with subparallel sides along all length. Pronotum transverse, about two times wider than long (Figs 1, 6); convex; anterior angles and sides depressed; hypomera not visible in lateral view; posterior margin slightly bisinuate, not emarginated medially; prosternum transverse, with marked transverse carina. Elytra slightly longer than pronotum (Figs 1, 6); around 1.5 times wider than long (Fig. 19); apico-lateral angles markedly sinuate. Wings well-developed. Mesoventrite process extended slightly posterior of middle mesocoxal cavities (Fig. 20); meso- and metaventrites processes fused, suture and isthmus absent, processes distinguished by differences in surface sculpture. Metepisternum with two setae in a single row on posterior one-third, bordered anteriorly and ventrally by carina. Tarsal formula 4-4-5; metatarsomere 1 about as long as 2. Abdomen with sides slightly convergent from base to apex (Figs 1, 6); segments III to VI with two pairs of paratergites, identical in length; segment VII with pair of very small paratergites; terga III to VI with pronounced transverse concavity; tergum VII with modified anterior margin for openings to abdominal glands, medial one-third broadly protruded; tergum IX divided into two lateral lobes, symmetrical ventral struts (Fig. 12); tergum X with setal patch square, apical half with four macrosetae on each side near the posterior margin and microsetae somewhat flattened (Fig. 12, detail). Aedeagus typical of subtribe, cylindrical sclerotized flagellum (Figs 13, 22); apical lobe of each paramere elongate, setae unequal and not all near apex.
Female. Similar to male, tergum IX without ventral struts; hemisternite IX visible fused on tergum IX; spermatheca typical of subtribe, latero-apical plate present, neck elongate distal to latero-apical plate (Fig. 17).
Remarks. Microbrachida shares with other three genera, Brachida, Probrachida and Encephalus, a broadly rounded ligula. Then, the differences from the two earlier genera are noted in the diagnosis. While Microbrachida can be distinguished from Encephalus by markedly sinuate apicolateral angles of elytra (Figs 1, 6); meso- and metaventrites processes fused and transversal suture absent (Fig. 20).
Bierig (1939) also described two monotypical genera from Panama: Brachycantharus Bierig, 1939 and Neobrachychara Bierig, 1939. In the same way as Kim & Ahn (2015), we point out here the differences among these genera and Microbrachida. Then, Microbrachida differs from Brachycantharus and Neobrachychara in having body sublimuloid and head strongly deflected (body subparallel-sided and head not deflected in Brachycantharus and Neobrachychara (Figs 1 and 3 in Bierig 1939).
description: Published as part of Caron, Edilson, Souza, Maria Geralda De & Pamblona, Ana Maria Santa Rosa, 2024, Rediscovery of Microbrachida Bierig, 1939, description of a new species from the Brazilian Amazon and its potential for biological control (Coleoptera, Staphylinidae), pp. 541-550 in Zootaxa 5537 (4) on pages 543-545, DOI: 10.11646/zootaxa.5537.4.6, http://zenodo.org/record/14240312