Ennearthron melancholicum Rosa-Oliveira and Lopes-Andrade, 2025

Rosa-Oliveira, Ayessa & Lopes-Andrade, Cristiano, 2025, Ennearthron Mellié (Coleoptera: Ciidae): composition of the species from the Atlantic Forest and new geographic records America, Journal of Natural History 59 (33 - 36), pp. 2203-2216 : 2206-2207

Ennearthron melancholicum Rosa-Oliveira and Lopes-Andrade sp. n.

( Figure 1 (A–J))

HISTORY

Etymology

The species name is from the Greek word ‘ melancholia ’, which means depression, deep sadness a reference to the abdominal sex patch of males, which resembles a sad face.

Diagnosis

This species differs from all others of the genus by the possession of a wide, shallow and broadly notch, rather than a straight one, separating the anterocephalic projections of males. It differs from E and E. cornutum in possessing an arch-shaped sexual mark on the first abdominal ventrite of addition, the morphology of the male genitalia is quite different from that of the other species: the

VIII with emarginate apex and rounded edges with long bristles. Tegmen widens gradually from apex, becoming more sclerotised from the middle to the apex; anterior margin rounded; median occupying about two-thirds of its length, dividing the apex into two lobes, each containing basiconic at the top and a strong membranous emargination. Penis with acute and membranous apex, bifurcated a slit in the centre occupying about four-fifths of its length, trapezoidal base, apical portion narrower E. victori .

Holotype. ( Figure 1 (A–D)). Adult male, fully pigmented, in good condition, but right antenna seven antennomeres. Measurements in mm: TL 1.56, PL 0.58, PW 0.62, EL 0.98, EW 0.68, GD 0.50.

PW 0.94, EL/EW 1.44, EL/ PL 1.69, GD/EW 0.74, TL/EW 2.29. Body elongate, convex, dorsum and venter antennae, palpi and tarsi brown yellow; dorsal vestiture of conspicuous suberect yellow bristles; vestiture of slender decumbent yellow setae. Head anterior edge visible from above; anterocephalic projected forward and upward, forming two lateral subtriangular plates, separated by a wide, rounded, shallow notch; borders of notch angulate, slightly projected, giving the appearance tubercles in the anterocephalic edges (better seen in dorsal view, Figure 1 (A)). Antennae with antennomeres, as follows (in mm, left antenna measured): 0.05, 0.04, 0.03, 0.02, 0.02, 0.01, 0.04, 0.04

( FL 0.08, CL 0.15, CL/FL 1.88). Eyes semioval, finely faceted, with about 70 ommatidia; GW 0.13 mm 0.61× as wide as head. Pronotum with single, dense, coarse punctation; interspaces microreticulate vestiture single, each puncture bearing one suberect bristle 0.02–0.03 mm long; anterior edge projected forward forming two subtriangular plates slightly curved upwards; lateral carinae slightly late, barely visible when seen from above. Scutellar shield subpentagonal, with few punctures and

BW 0.09; SL 0.05. Elytra with single punctation; punctures coarse, subseriate; interspaces smooth;

single, each puncture bearing one thick suberect bristle 0.03–0.04 mm long. Metathoracic wings oped, apparently functional. Hypomera with shallow punctation; interspaces microreticulate.

biconcave; surface microreticulate. Prosternal process broad, about as long as prosternal disc, enlarged, broadly rounded at apex. Protibiae about 3.8× as long as maximum width (at apex); outer angle strongly projected into a tooth. Meso- and metatibiae about 4.5× and 5.6× as long as respectively; outer apical angle broadly rounded. Metaventrite subglabrous, with shallow interspaces microreticulate; discrimen about one-third the length of metaventrite at midline.

ventrites microreticulate, with shallow punctures; length of ventrites (in mm, from base to apex longitudinal midline) as follows: 0.21, 0.08, 0.07, 0.05, 0.07; first abdominal ventrite with an arch-shaped patch anteriorly convex ( Figure 1 (E)), with a transverse diameter of 0.11 mm. Male abdominal terminalia a paratype; Figures 1 (F–I)): sternite VIII ( Figure 1 (F)) posterior edge membranous at middle, with rounded, a bit sclerotised, bearing a few thick long setae, anterior edge membranous; basal piece in any of the dissected specimens; tegmen ( Figure 1 (H)) 3× as long as wide, about as long as penis, gradually from base to apex, more sclerotised from middle to apex, anterior edge rounded, emargination about two-thirds of its length, dividing apex into two lobes, each containing basiconic at the tip; penis ( Figure 1 (I)) 4.4× as long as wide, bifurcated apically, with sclerotised median containing basiconic sensilla; base trapezoidal-shaped.

Figures

Figure 1. Ennearthron melancholicum sp. n., male holotype (A–D), male (E–I) and female (J–L) paratypes. Holotype