Mixaderus lemagneni, Gompel, 2021

Gompel, Nicolas, 2021, New Mixaderus species from the Mascarene Islands (Coleoptera: Aderidae), Zootaxa 4969 (1), pp. 166-174 : 168-169

Mixaderus lemagneni n. sp.

( Figures 1e , 2d,k,p,t )

Etymology. This taxon is named after my colleague Emmanuel Lemagnen in appreciation of his active support of my work on Aderidae from the Mascarene islands.

Type locality. France: La Réunion, Sainte-Marie, La Ressource, (310 m) [20°56’ S 55°31’ E] .

Distribution. France: La Réunion.

Description. Body length. ♂: 1.63± 0.11 mm (n=5); ♀: 1.77± 0.17 mm (n=3). Body bicolour, head black, pronotum dark brown, elytra brown with broad white markings. Appendages yellow and brown.

Head. Transverse, black, slightly wider than pronotum. Frons weakly convex. Palpi yellow. Punctuation dense and fine. Pubescence double, dense, wholly, white, homogeneous, largely covering the tegument. Eyes nearly reaching the posterior edge of the head in side view, or separated from it by a strip of tegument narrower than the width of a row of ommatidia ( Figure 2t ).

Antennae ( Figure 2k ). Uniformly yellow, or at most orange in distal half, contrasting with M. gomyi Gompel, 2012 , in which only the first 3‒4 antennomeres are pale and the rest of the antenna is dark brown. Thin, almost as long as elytra in males, about a third shorter than elytra in females, pubescent. Antennomeres 3‒5 regularly cylindrical, 8‒10 conical with apex broader, and antennomere 11 than twice longer than penultimate, asymmetrical and rounded.

Pronotum. Convex, rounded, marked by a pair of dimples just anterior to the posterior border. Sides straight. Surface densely punctuated, the space between punctures equivalent to the puncture diameters, punctures of intermediate size, deep. Pubescence dense, double, golden anteriorly and white in the posterior third, including in the dimples, with a sharp, sinuate boundary between anterior and posterior.

Elytra. Length: ♂: 1.15± 0.08 mm (n=5); ♀: 1.24± 0.11 mm (n=3). Sides subparallel, rounded posteriorly, with humeral callus well marked. Punctuation stronger and deeper and as dense as on the pronotum, space between punctures equal to the puncture diameters on disc. Disc depressed. Pubescence short, golden, comprised of longer setae borne from the punctuation and interspersed pruinosity, with a distinct pattern of white pubescence on each elytron, formed of three elements: a weak and small humeral spot, a broad anterior transversal band at the level of the disc, hardly reaching the elytral suture and broadening on the elytral disc, and a second posterior transversal band on the declivity, curved and not reaching the elytral suture.

Legs. Simple, tibiae and tarsae of fore- and midlegs yellow, femora darker in the proximal half; hindlegs with femora brown, except their apex, which is yellow, hindtibiae brown in their proximal half and yellow in their distal half, tarsae yellow.

Sexual dimorphism. First article of the male foretarsae very broad and longer than the next two articles together. This character is also more pronounced than in the closely related species M. gomyi Gompel, 2012 ( Figure 2o,p ). Antennae a third longer in males than in females.

Aedeagus ( Figure 2d ). Oblong, apicale tapered in apical fifth in dorsal view, ending in a small semi-circular knob (inset on Figure 2d ; compare to the simple tip of M. gomyi ’ phallus: inset on Figure 2e ). Phallobase short, a fifth of total phallus length (a third of phallus length in M. gomyi , Figure 2d,e : double arrows). Accessory lobes of the apicale present, not extending beyond the phallus tip.

Type material. France: La Réunion, Côte Sud-Est , 29.X.1937, J. Vinson leg. (1 ♂ paratype, BMNH) ; La Réunion, Saint-Denis, La Grande Chaloupe , N18 [20°53’ S 55°22’ E], 2.III.2006, J. Poussereau leg. (1 ♀ paratype, NGPC) ; La Réunion, Saint-Denis, La Grande Chaloupe , N18 [20°53’ S 55°22’ E], 19.II.2009, S. Gasnier leg. (1 ♀ paratype, NGPC) ; La Réunion, Saint-Denis, La Grande Chaloupe , [20°53’ S 55°22’ E], 28.I.2009, J. Poussereau leg. (1 ♀ paratype, MHNRUN) ; La Réunion, Sainte-Marie, La Ressource , (310 m) [20°56’ S 55°31’ E], 2.III.2015, E. Lemagnen leg. (1 ♂ and 1 ♀ paratypes, ELPC; 1 ♂ holotype, NGPC) ; La Réunion, Sainte-Marie, La Ressource , (310 m) [20°56’ S 55°31’ E], light trap, 26.I.2018, E. Lemagnen leg. (1 ♂ paratype, ELPC) .

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.