Chimalfus brunneus, Larsen & Solodovnikov & Reyes-Hernández, 2025

3.1.4. Chimalfus brunneus sp. nov

Figs. 1B View Fig , 2B View Fig and 4 View Fig and 6 View Fig .

Holotype: CHILE: Chiloe ´Pr.: Quemchi, 11 km W of ( 11 km E Hwy 5), 140m, 42 ◦ 10.40′S, 73 ◦ 35.73′W, 10–21.xii.2002, Valdivian rainforest remnant w/thick bamboo//understoty: FMHD #2002-067, carrion trap (octopus). Thayer, Newton, Clarke 1060 FIELD MUS. NAT. HIST.//[sex label]//| FMNH-INS 0000 024 194 [Deposited in FMNH]. GoogleMaps All other material examined are paratypes and they are listed in the Supplementary File 1.

3.1.5. Description

Measurements Ƌ [min–max(average); n = 5]: FBL = 3.11–3.41 (3.25); TL = 5.16–7.16 (6.14); HW = 0.70–0.74 (0.72); HL = 0.76–0.91 (0.85); HW/HL = 0.79–0.92 (0.84); PW = 1.06–1.20 (1.15); PL = 0.86–1.00 (0.95); PW/PL = 1.09–1.30 (1.21); EW = 0.70–0.74 (0.72); EL = 1.38–1.51(1.45); PW/HW = 1.09–1.30 (1.21).

Measurements ♀ [min–max(average); n = 5]: FBL = 2.95–3.35 3.21); TL = 5.59–6.51 (6.09); HW = 0.65–0.76 (0.72); HL = 0.75–0.89 (0.85); HW/HL = 0.80–0.91 (0.85); PW = 1.03–1.25 (1.17); PL = 0.84–1.01 (0.95); PW/PL = 1.17–1.27 (1.23); EW = 1.20–1.57 (1.37); EL = 1.30–1.49 (1.41); PW/HW = 1.49–1.75 (1.62).

Body coloration uniformly dark-brown, with light brown apical margins of apical abdominal segments, edge of pronotum, and around eyes. Legs from dark to light brown. Mouthparts brown. Antennae may vary from yellowish-brown (entirely or darkening from antennomere 4) to entirely dark brown.

Head longer than wide; dorsally and ventrally slightly glossy with numerous micropunctures, posterior angles with sparse, small setiferous punctures; with microsculpture of transverse to concentric waves; eyes small-sized (EYL/HL = x = 0.44); distance between eyes about 1.4 times the length of eyes in both sexes. Nuchal ridge not fused with infraorbital ridges.

Antennal proportions as follows: a1 at least 1.5 times longer than a2; a2 slightly shorter than a3 but slightly longer than a4; a4 to a6 subequal in length; a7 to a10 subequal in length; a11 around 1.5 times longer than a10, in both sexes. All antenomeres longer than wide.

Pronotum slightly wider than long, convex, evenly curved anteriad and posteriad; flexible postcoxal hypomeral extension rounded, as wide as long, uninterrupted by inferior line.

Elytra distinctly longer than pronotum. Mesosternum with fourteen macrosetae, may rarely have one more or less. Metathoracic wings well developed.

Protarsomeres 1–3 distinctly wider than long. Internal ridge of procoxa running along external ridge. Metatarsi with first tarsomere longer than last tarsomere; empodial setae slightly shorter than tarsal claws in all tarsi; metacoxae with four or more spines on posterior margin; metatrochanter sharply pointed at apex.

Abdomen with tergite II with setiferous punctures restricted to sides of apical margin; tergite VII with white fringe along posterior edge. Male sternite VIII exhibits broad and shallow U-shaped emargination.

Aedeagus ( Fig. 4B and C View Fig ), its total length ~ 0.95 mm. Median lobe rod-like. Paramere distinctly produced over apex of median lobe, with slight constriction at basal half and pronounced expansion at about three-quarters of total length, tapering to sharp rounded tip; in lateral view paramere appears straight.

Comparison. This species is differentiated from others by the following combination of characters: length of eyes less than half the length of head (EYL/HL = x = 0.44), frons microsculpture with transverse to concentric waves, metathoracic wings well developed, and tergite VII with white fringe along posterior edge.

The head chaetotaxy of this species is particularly distinct compared to other Chimalfus species and L. nana . While the pronotum is also statistically significantly different, its morphospace shows considerable overlap with C. discoideus ( Fig. 9 View Fig ; see section 3.2 for more details).

Distribution. C. brunneus is distributed primarily in southern Chile, ranging from the Nuble ˜Region to the Ays´en Region, with a predominant presence in the Valdivian temperate rainforest.

Etymology. The specific epithet brunneus is derived from the Latin word “brunneus ,” meaning brown, referring to the species’ distinctive brown coloration.