Macrotrichurus granzottorum Da-Silva, Caron & Moreno, sp. nov.

(Figs. 1–12)

Diagnosis. Macrotrichurus granzottorum sp. nov. can be recognized from other species in the genus by the following combination of characters: head with one pair of bristles medially at vertex; ligula almost indistinct; mandibles toothless; outer lateral margin of elytra with five long bristles; tergite VIII longer than wide, with two transversal rows each with four long bristles.

Description

Head. Transverse, posterior margin somewhat sinuate with posterior angles rounded; slightly convex in lateral view; vertex slightly elevated; surface with one pair of bristles medially, symmetrically distributed, and two bristles near each eye; ventrally with long bristles on each side of head and small pores sparsely distributed; hypostomal suture distinct. Fronto-clypeal suture marginate medially (Figs. 4A–B). Antenna with 10 antennomeres deeply inserted under anterior region of vertex; antennomere 2 longer than wide, somewhat cylindrical; 3 longer than wide, gradually narrowing basad, shorter than previous; 4, shortest, strongly transverse; 5 transverse; 6 subquadrate, slightly longer than 5; 7 transverse; 8 subquadrate; 9 longer than wide, slightly shorter than 10; 10 conical, the longest, bearing one pair of coeloconical sensilla (Figs. 4C–D, 5C). Labrum transverse, bristles p1-p2, m1-m2, d1- d2 present; medial lobes indistinct, a- and b-sensillum present; medial membranous lobes indistinct (Figs. 4G, 5A). Mandibles falciform, symmetrical, gradually narrowing towards apex; dorsal sensitive pores sparsely distributed; prostheca blade-like, occupying almost half of total mesal length (Figs. 4H, 5B). Maxilla with 4 articles, slender, covered with long and sparse bristles; article 1 small, almost indistinct; 2, longer than wide, slightly dilated at outer margin; 3, cylindrical, subequal in length to previous; 4, conical, shorter than previous, covered with elongated sensillum; cardo narrow, somewhat ovoid; stipes longer than wide, basistipe distinctly wider than ditistipe; lacinia narrow, narrower and slightly shorter than galea in length, with bristles distributed internally along the entire length; galea falciform, with comb of bristles at apex (Figs. 4I, 6A–B). Labium with 3 articles; 1 subquadrate; 2 cylindrical, the longest; 3, narrow, longer than wide; ligula indistinct and broadly rounded (Fig. 4F). Mentum fused to submentum; mentum somewhat hexagonal, lateral margins rounded and anterior margin slightly emarginate medially; short bristles sparsely distributed on surface; gular sutures parallel (Fig. 4E).

Thorax. Pronotum flattened and smooth, almost as wide as elytra; lateral margins declivous, hypomera not visible in lateral view; anterior margin broadly emarginate medially, anterior angles narrow and distinct; posterior margin almost straight with posterior angles distinct; surface covered with long bristles symmetrically distributed; longitudinal row of six bristles on each lateral margin; one transversal rows of four bristles on anterior margin and posterior margin; additional row of fringing bristles distributed across posterior border (Fig, 7A). Elytra with outer apical angle broadly rounded, outer margin arcuate; basal margin and apical margin declivous; covered with long bristles; five bristles on lateral outer margin and eight bristles sparsely distributed on surface. Inner anterior margin of elytra with scamose tooth (Figs. 6C–D, 7B). Hind wings present. Meso-metanotum membranous, shorter than meso-metaventrite; metanotum with one pair of bristles symmetrically distributed medially, alacrista smooth and parallel; postnotum covered with small and black bristles (Figs. 7C, 8A). Meso-metaventrite weakly sclerotized, subequal in length; mesoventrital process pointed and narrow, reaching near coxal cavities, uniformly covered with short bristles; metaventrite somewhat concave, glabrous in most, with four long bristles on posterior border; metendosternite U-shaped, furcal arms broader at tips, median process absent (Figs. 7D, 8B). Legs (Figs. 7E–G) densely covered with bristles; front coxa transverse, flattened (Fig. 7E); middle coxa somewhat oval (Fig. 7F); hind coxa triangular (Fig. 7G); front, middle, and hind trochanter increasing in length; tibia subequal in length to femur and one pair of tibial spurs on all legs; front and middle tibia with thicker spines in addition to tibial spurs; tarsal formula 4-4-5, 4 th and 5 th articles of hind tarsus separated by a clear line of division (Fig. 9C); first tarsomere of front, middle, and hind tarsi increasing in length (Fig. 9A–C); first tarsomere of hind tarsi almost as long as the remaining tarsomeres combined; pair of falciform claws on each last tarsomere (Figs. 9A–C).

Abdomen. Fusiform, slightly physogastric ventrally. Tergites and sternites separated by two pairs of narrow and transverse paratergites on abdominal segments III–VI. Tergites III–VI with transverse row of six bristles on posterior border. Tergite I membranous, almost indistinct; II–VI transverse. Sternite III with anterior margin broadly sinuate on middle third (Fig. 2B, 3C). Sternites III–V with posterior margin conspicuously emarginate on middle third (Fig. 2A, B, 3C). Tergite VII subquadrate, densely covered with short bristles on surface, with transverse row of six bristles symmetrically distributed on posterior margin, posterior margin broadly emarginate medially, with fringe of fine bristles; anterior margin sinuate, with narrow and prominent outer angles, with one single and transverse glandular area medially, lateral margins parallel (Figs. 10A, 11A–D). Tergite VIII longer than wide, anterior angles forming one pair of narrow and prominent struts; anterior and posterior line of bristles each with four bristles in both sexes (Figs. 10C, G). Sternite VIII wider than long in males, with latero-posterior margins broadly rounded, anterior margin straight, anterior line of bristles with six long bristles, posterior line with four bristles (Fig. 10D); females with sternite longer than wide, with lateral margins parallel, and posterior margin rounded, anterior angles forming a pair of short struts (Fig. 10J); each lateral margin with one bristles; anterior and posterior line of sternite each with four long bristles; fine fringe of short bristles on middle third of posterior border of sternites on both sexes. Tergite IX broad and somewhat triangular, slightly narrowing toward apex, males with narrow and long struts anteriorly; with five long bristles sparsely distributed (Fig. 10B). Sternite IX of males elongate, weakly sclerotized, with three sensillum-like bristles on posterior margin (Fig. 10B); sternite IX of females divided into two hemiesternites, narrow and attached to each sternite IX (Fig. 10I). Tergite X narrow, fusiform, densely covered with long bristles on both sexes, slightly emarginate medially (Figs. 10B, H). Aedeagus. Median lobe simple, with bulbus broadly rounded, tubulus elongate with narrow tip, internal sac without modifications (Fig. 10E). Parameres, each with paramerite broad, apical lobe somewhat triangular, with two long bristles; medial phragma triangular, with fine bristles, similar to punctures; condylite narrow; velar sac indistinct (Fig. 10F). Spermatheca with stem cylindrical, and capsule rounded and sclerotized (Fig. 10K).

Material examined. HOLOTYPE. ♂ (CESP, in alcohol 98%), labels: “ Fazenda Três Palmeiras / Amambaí, MS, BR / 21. IX. 2024 / col. C. Moreno; R. F. Silva ” // “HOLOTYPE”. PARATYPES. 13: 1♂ (CESP), same data as holotype. Four paratypes to be sent to MZSP (2 ♂ and 2 ♀) (MZSP 21471), four to FMNH (4 ♂) and four to MPEG (4 ♂). Additional material. 3 ♂ and 2 ♀, same data as holotype, dissected on slides.

Remarks. The new species is most similar to M. brasiliensis in general appearance but can be distinguished from it and also from M. notabilis by the absence of the stout ligula, as well as by one pair of bristles at the vertex of head surface (M. notabilis and M. brasiliensis has two pairs of bristles), and by the tergite VIII being longer than wide, with two rows of four bristles on the surface (in M. brasiliensis and M. notabilis this tergite is subquadrate, with a single row of six bristles).

Etymology. A commemorative name, that granzotto- is a family name, and -orum treated the name as noun in the genitive case, plural. The specific epithet granzottorum honors the Granzotto family, in recognition of their exceptional hospitality at Fazenda Três Palmeiras, in the type locality of the new species, and their invaluable assistance during fieldwork.

Distribution. The species is only known from its type-locality: Amambaí, Mato Grosso do Sul, Brazil (approximately 23°14’S, 54°48’W) (Fig. 12).

Host termites. This species was found in epigeal (above-ground) nests of Patawatermes turricula (Silvestri). This is the second record of a termitophilous rove beetle occurring with this termite genus.

Behavioral notes. We placed specimens of Macrotrichurus granzottorum sp. nov. in a Petri dish under two different conditions: with and without their termite hosts. In the absence of termites, M. granzottorum sp. nov. individuals walked with their abdomens fully extended and deflected downward. When in the presence of termites, the beetles frequently raised their abdomens over their backs when encountering a termite. This behavior became more pronounced when we touched the beetles with entomological forcep, prompting the same reaction. This type of response is common among some termitophilous beetles and suggests a defensive function. It is likely that the beetles not only try to shield themselves but also expose the tip of the glandular opening on the seventh tergite, possibly to appease their hosts (Kistner & Jacobson 1976; Kistner 2001; Kistner 2004).