Brachystomella porcus Denis, 1933

Queiroz, Gabriel C. & Mendonca, Maria Cleide de, 2013, New species of Brachystomellidae and characterization of Micronella porcus (Denis, 1933) from Brazil, ZooKeys 316, pp. 81-98 : 89-90

Brachystomella porcus Denis, 1933 Figs 29-41

Examined material.

One female on slide, Label: Nº 2037 CM/MNRJ (C), Alto Caparaó, MG, Brasil, Queiroz, G.C. leg, 12.iv.2011, 20°26'7"S, 41°47'54"W; 1 female on slide and 2 specimens in ethanol, Nº 2041 CM/MNRJ (D), Alto Caparaó, MG, Brasil, Queiroz, G.C. leg, 13.iv.2011, 20°26'7"S, 41°47'54"W; 1 female and 1 juvenile on slides, Label: Nº 2353 CM/MNRJ (C and E), Alto Caparaó, MG, Brasil, Queiroz, G.C. leg, 11.iv.2012, 20°26'7"S, 41°47'54"W; 1 young female and 1 juvenile on slides, Label: Nº 2354 CM/MNRJ (A and B), Alto Caparaó, MG, Brasil, Queiroz, G.C. leg, 11.iv.2012, 20°26'7"S, 41°47'54"W. Deposited at MNRJ, Rio de Janeiro, Brazil. Two specimens deposited at MNHN, Paris, France: 1 female on slide MNHN-EA011501; 1 female on slide, Label: MNHN-EA011500, Alto Caparaó, MG, Brasil, Queiroz, G.C. leg, 13.iv.2011, 20°26'7"S, 41°47'54"W.

Locality.

Brasil, Minas Gerais: Alto Caparaó municipality, Parque Nacional do Caparaó (ICMBio), 20°26'7"S, 41°47'54"W, leaf litter and soil of "campos de altitude", 2,700 m a.s.l.

Characterization of Brazilian specimens.

Habitus typical of the genus. Body length range of specimens: 0.45-0.95 mm. Color in ethanol: white, no pigmentation.

Ratio head diagonal: antenna = 1:0.57. Ant I with 7 chaetae. Ant II with 12 chaetae. Ant III and IV fused dorsally, ventral separation marked. Sensory organ of Ant III with two club-shaped sensilla; two longer and subcylindrical guard sensilla, the dorsal is stouter than ventral guard sensilla; ventral microsensillum present (Figs 29-31). Ant IV with simple apical bulb and six slender sensilla; dorsolateral microsensillum present; subapical organite round; with about 30 ventral chaetae (Fig. 30).

Without eyes. PAO bearing 7-8 vesicles disposed as a rosette. Maxilla quadrangular with 6-7 teeth (Fig. 32). Labral formula: 2/2334. Labium typical of Brachystomella , with one papillated chaeta (L) and four proximal chaetae (Fig. 33).

Head chaetotaxy as in Fig. 34. Chaetae a0 present, but some specimens with asymmetries; Oc chaetae 3+3. Dorsal chaetotaxy composed of smooth ordinary chaetae (15-20 µm) and longer sensilla (20-25 µm) that becomes longer towards distal segments of the body. Ratio ordinary chaetae: sensilla = 1:1.3. Th I with 2+2 chaetae; sensillar formula by half tergum: 022/211110 (Fig. 35).

Chaetotaxy of legs I–III as follows: Scx I– 1, 2, 2; Scx II– 0, 2, 2; Cx– 3, 6, 7; Tr– 5, 5, 4; Fe– 12, 11, 10; Tita– 19, 19, 18. Tenent hair on tibiotarsi acuminated; unguis without tooth (Fig. 36). Ventral tube with 3+3 chaetae. Without tenaculum. Furca completely absent, but with a well-defined furcal area with six chaetae (Figs 37-38). Abd VI with 4+4 chaetae on dorsal side and one unpaired chaetae; with 3+3 chaetae on the ventral side (Fig. 39). Each anal valve with 12-13 chaetae and 2 hr chaetae; (Fig. 40). Female genital plate as in Fig. 41.

Remarks.

The examined specimens from Minas Gerais State, Brazil, fit the description of the Neotropical species Micronella porcus . The six sensilla on Ant IV, the club-shaped sensilla on Ant III organ, the 6-8 vesicles on PAO and the toothless unguis are the main characters that define the species. The description above adds important characters such as head and dorsal body chaetotaxy and also the number of chaetae on furcal area to the original description.