Mixaderus reunionensis, Gompel, 2021

Gompel, Nicolas, 2021, New Mixaderus species from the Mascarene Islands (Coleoptera: Aderidae), Zootaxa 4969 (1), pp. 166-174 : 167-168

Mixaderus reunionensis n. sp.

( Figures 1a , 2a,h,q )

Etymology. The species’ name refers to its geographical origin.

Type locality. France: La Réunion, Saint-Philippe [21°22’ S 55°42’ E] .

Distribution. France: La Réunion.

Description. ♀ unknown. Body length. ♂ holotype: 1.80 mm. Body entirely dark with pattern of white pubescence. Appendages black and orange.

Head. Transverse, dark, wider than pronotum. Frons flat. Palpi orange. Punctuation relatively sparse (compared to pronotum), punctures large and shallow. Pubescence double, dense, white, homogeneous, largely covering the tegument, converging toward the midline between the eyes. Eyes weakly convex, forming a continuous curve with the frons, not reaching the posterior edge of the head in side view, separated from the border by a thin strip of tegument (at least the width of two rows of ommatidia; Figure 2q ).

Antennae ( Figure 2h ). Thick, a third shorter than elytra, black, except the first two antennomeres, which are dark brown and the tip of the last antennomere, which is orange. Slightly and regularly thicker toward apex, antennomeres short, conical, last antennomere twice as long as penultimate, rounded.

Pronotum. Convex and transverse, marked by a strong impression with two pairs of dimples just anterior to the posterior border. Sides regularly curved. Surface, densely punctuated, the space between punctures reduced to ridges, punctures of intermediate size, deep. Pubescence dense, double, golden anteriorly and white in the posterior third, with a sharp, sinuate boundary between anterior and posterior.

Elytra. Length: ♂ holotype: 1.30 mm. Long, sides subparallel, humeral callus well marked. Punctuation strong and deep, but less dense than on the pronotum (space between punctures, however, smaller than the puncture diameters). Disc slightly convex, with a broad callus around the scutellum. Pubescence dense, wholly, golden, comprised of setae borne from the punctuation and interspersed pruinosity, with a distinct pattern of white pubescence on the elytra, formed of a large hook connecting the humeral callus to the middle of the external margin on each elytron. Scutellum covered with white pubescence.

Legs. Simple (no apparent sexual characters). Femora black with apex progressively lighter, orange. Tibiae dark in their central portion, base and apex paler. Tarsae yellow.

Aedeagus ( Figure 2a ). Large. Sides slightly divergent in from the base to the apical fourth in dorsal view. Apex sub-triangular, with slight sinuosities on the sides. Long, thick and blunt accessory lobes prominent on each side of the apicale.

Type material. France: La Réunion, Saint-Philippe, Basse Vallée , (30 m) [21°22’ S 55°42’ E], 7. VI .2012, J. Poussereau leg. (1 ♂ holotype, MHNRUN) .

Figures

FIGURE 1. Habitus of new species of Aderidae from the Mascarene Islands. a, Mixaderus reunionensis n. sp. (♂ holotype from La Réunion); b, Mixaderus tamisieri n. sp. (♂ paratype from La Réunion); c, Mixaderus mauritiensis n. sp. (♀ holotype from Mauritius); d, Mixaderus chassaini n. sp. (♂ holotype from La Réunion); e, Mixaderus lemagneni n. sp. (♂ paratype from La Réunion); f, Mixaderus voisini n. sp. (♀ paratype from La Réunion). Scale bars: 0.5 mm.

FIGURE 2. Anatomy of new species of Aderidae from the Mascarene Islands. a–g: aedeagus of a, Mixaderus reunionensis n. sp. (♂ holotype from La Réunion); b, Mixaderus chassaini n. sp. (♂ holotype from La Réunion); c, Mixaderus tamisieri n. sp. (♂ paratype from La Réunion); d, Mixaderus lemagneni n. sp. (♂ paratype from La Réunion); e, Mixaderus gomyi Gompel, 2012 (♂ holotype from La Réunion); f–g, Mixaderus voisini n. sp.: f, anterior struts retracted (♂ holotype from La Réunion); g, anterior struts extended from phallobase (♂ paratype from La Réunion). h–o: antennae of h, Mixaderus reunionensis n. sp. (♂ holotype from La Réunion); i, Mixaderus chassaini n. sp. (♂ holotype from La Réunion); j, Mixaderus tamisieri n. sp. (♂ paratype from La Réunion); k, Mixaderus lemagneni n. sp. (♂ paratype from La Réunion); l, Mixaderus gomyi Gompel, 2012 (♂ holotype from La Réunion); m, Mixaderus mauritiensis n. sp. (♀ holotype from Mauritius); n, Mixaderus voisini n. sp. (♀ paratype from La Réunion). o,p: male right prothoracic tarsae of o, Mixaderus gomyi Gompel, 2012 (♂ holotype from La Réun- ion); p, Mixaderus lemagneni n. sp. (♂ paratype from La Réunion). q–v: Mixaderus head schematics in side view. q, Mixaderus reunionensis n. sp.; r, Mixaderus chassaini n. sp.; s, Mixaderus tamisieri n. sp.; t, Mixaderus lemagneni n. sp.; u, Mixaderus voisini n. sp.; v, Mixaderus mauritiensis n. sp. Scale bars: 0.1 mm.