Mixaderus voisini, Gompel, 2021

Gompel, Nicolas, 2021, New Mixaderus species from the Mascarene Islands (Coleoptera: Aderidae), Zootaxa 4969 (1), pp. 166-174 : 170-171

Mixaderus voisini n. sp.

( Figures 1f , 2f,n,u )

Etymology. The species is named after my colleague Jean-François Voisin.

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

Distribution. France: La Réunion.

Description. Body length. ♂: 1.43± 0.10 mm (n=8); ♀: 1.48± 0.08 mm (n=10). Body entirely black, shiny. Appendages yellowish with darker markings.

Head. Transverse, black, slightly wider than pronotum. Frons flat. Palpi yellowish. Punctuation indistinguishable, surface shiny. Pubescence scarce, double, pruinosity almost invisible, Tegument well apparent, not masked by the pubescence. Eyes separated from the posterior edge of the head by a narrow but distinct strip of tegument in side view ( Figure 2u ).

Antennae ( Figure 2n ). Thin, relatively long, 70% (♀) or 80% (♂) the length of the elytra, entirely orange, pubescent. Antennomeres 4‒8 regularly cylindrical, longer than wide, antennomeres 9‒10 transverse, conical, and antennomere 11 thickened, more than twice longer than penultimate.

Pronotum. Round, weakly convex on the disc, sub-quadrate to slightly transverse, marked by a pair of shallow dimples just anterior to the posterior border, difficult to see in most specimens. Sides straight, converging weakly toward the base. Surface shiny, densely punctuated, punctures large, shallow, separated by less than a puncture diameter. Pubescence short, with longer blond setae arising from the punctures, and scarce shorter hairs in between, not masking the tegument.

Elytra. Length: ♂: 1.0± 0.06 mm (n=8); ♀: 1.07± 0.05 mm (n=10). Long, sides convex forming a long oval, with humeral callus well marked. Surface shiny, densely punctuated on disc, punctures large, shallow, separated by a puncture diameter. Punctuation progressively scarcer and shallower on the declivity. Disc depressed or weakly convex. Pubescence short, blond, comprised of appressed setae borne from the punctuation and scarce, hardly visible interspersed short blond hairs, the latter almost completely absent in some specimens.

Legs. Simple (no apparent sexual characters), tarsae of all legs yellowish, foretibiae yellowish, tibiae of mid- and hindlegs yellowish, often brown in their proximal halves, all femora brown in their proximal halves.

Aedeagus ( Figure 2f ). Progressively and regularly tapered from base to apex, phallobase long, two fifths of the phallus’ length. Accessory lobes present, not reaching the apex of phallus. Anterior struts long, sometimes pulled out and extending from the phallobase.

Type material. France: La Réunion, Saint-Philippe, Réserve biologique, (10 m) [21°21’ S 55°46’ E] , 14. VI .2012 , J. Poussereau (2 ♂ and 1 ♀ paratypes, MHNRUN; 2 ♂ and 1 ♀ paratypes, NGPC); La Réunion, Saint-Philippe, Station 1 [21°22’ S 55°42’ E], beating, 14. VI .2012 , J. Poussereau (1 ♀ paratype, MHNRUN), 28. VI .2012 , J. Poussereau (1 ♀ paratype, NGPC); La Réunion, Saint-Philippe [21°22’ S 55°42’ E], beating Euonymus europaeus 14. VI .2012 , J. Poussereau (1 ♀ paratype, MHNRUN; 1 ♂ holotype, 1 ♂ and 1 ♀ paratypes, NGPC); Saint-Philippe, Station 2 [21°22’ S 55°42’ E], beating, 14.VIII.2012, J. Poussereau (1 ♂ and 1 ♀ paratypes, MHNRUN; 1 ♀ paratype, NGPC); La Réunion, Saint-Benoît, Grand étang (550 m) [21°05’ S 55°38’ E], beating Pandanus utilis , 19. V.2014, V. Legros leg. (2 ♀ paratypes, MHNRUN; 1 ♂ paratype, NGPC) .

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.