Hydraena quatriloba, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 35-38

Hydraena quatriloba , new species

Figs. 24 (habitus), 28 (aedeagus), 239 (map)

Type Material. Holotype (male): Toliara, Andohahela NP, Tsimelahy , pools in creek, 24° 57' S, 46° 37' E, 15–16 xi 2007, J. Stastny ( NMW) . Paratypes (15): Same data as holotype (11); Toliara, Manakaravavy, Manakaravavy R. dried out river with waterpools on sandy bottom with algal mats, N:-24° 31.222, E:44° 37.388, elev. 219 m, 24° 31' S, 44° 37' E, 18 v 2006, Bergsten et al. (P49) (1 NHRS) ; Menarandra, Menarandra R., 40km from Ampanihy , pools beside a river close to village, algae in pools and sandy bottom with some wood, 18.v.2006, P50, N:-24° 43.104, E:45° 2.859, elev. 227 m, 24° 43' S, 45° 3' E, 18 v 2006, Bergsten et al. (P50) (1 NHRS) ; Tsimelahy (Tulear), Analamatsaky , ditches near the village (dead branches of small stream), elev. 100 m, 24° 56' S, 46° 38' E, 6 ix 2001, Gerecke & Goldschmidt (MD 62) (2 NMW) .

Differential Diagnosis. Very similar in size and habitus to H. bisinuloba ; reliable determinations will require dissection of males. The distal process is shaped differently in the two species, among other differences in the aedeagi ( Figs. 26, 28).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.69/0.72; head width 0.44; pronotum 0.41/0.54, PA 0.47, PB 0.51; elytra 1.01/0.72.

Dorsum with head and pronotal disc dark brown to piceous; pronotum with margins light brown to brown; elytra brown; legs light brown to testaceous; maxillary palpi light brown to testaceous, distal 1/3 of last palpomere slightly darker, except tip testaceous.

Head with clypeus moderately finely and moderately densely punctate, interstices shining on median area, lateral areas microreticulate, dull; frons coarsely densely punctate, interstices ca 0.5–1xpd. Pronotum coarsely densely and deeply punctate, interstices narrow walls or less than 1xpd, except slightly larger, ca. 1xpd, on center of disc, shining. Mentum moderately finely punctate, interstices shining; postmentum weakly rugose, dull. Genae raised, shining, posterior margin abrupt, posterior ridge absent.

Pronotum sinuate laterally; anterior margin straight behind eyes, emarginate behind frons; PF1 absent; PF2 very shallow; PF3 and PF4 deep, confluent.

Elytra weakly arcuate laterally; posterior declivity steep, summit slightly past midlength; lateral explanate margins moderately wide; each elytron with very low, indistinct tumidity on posterior declivity; serial punctures round, separated by ca. 0.5–1xpd, slightly smaller than largest pronotal punctures. Intervals very weakly if at all raised, shining, ca. 0.5–1xpd. Apices in dorsal aspect conjointly truncate, in posterior aspect margins forming deep angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s [anteriorly]) ca. 1/0.2/2.5/1. P1 laminate; median carina weakly sinuate in profile. P2 l/w ca. 2/1, sides parallel, apex blunt. Plaques very narrow lines, not carinate, straight or very weakly arcuate, converging anteriorly, widely separated posteriorly, ca. 2x as wide as anteriorly, located at sides of deep median depression. Metaventrite anteromedian carina very small, short and low, almost absent; short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at arcuate posterior margin ca. 2x P2. Protibia very weakly arcuate, distal 0.5 slightly thickened. Mesotibia and metatibia straight, slender. Metafemur rather slender, slightly arcuate on lateral margin, slightly sinuate on medial margin. Abdominal apex with deep apicomedian notch.

Etymology. Named in reference to the four lobes of the aedeagus.

Figures

FIGURE 24. Hydraena quatriloba, holotype, habitus dorsal, lateral, and ventral.