Aulacochthebius perlaevis Perkins 2017, new species
Creators: name: Perkins, Philip D.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Hydraenidae
Aulacochthebius
Aulacochthebius perlaevis

description: Aulacochthebius perlaevis, new species
Figs. 211 (habitus), 213 (aedeagus), 305 (map)
Type Material. Holotype (male): Mahajanga, Boeny: Mahavavy Kinkony RS. S 16.15890 E 0 45.93967, 11 m. a.o., 3 xii 2009, J. Bergsten, N. Jönsson, T.Ranarilalatiana, HJ. Randriamihaja (MAD09-21) (NHRS). Paratypes (334): Same data as holotype (26 NHRS); Antsiranana, Ankarana, 1er canyon, river, elev. 50 m, 12° 57' S, 49° 8' E, 1 xi–30 xii 2004, M. Balke (MD 020) (7 ZSMC), one female (" MNCN AI-548 DNA specimen"); Antsaba, waterhole in streambed, elev. 50 m, 14° 0' S, 48° 50' E, 1 xi–30 xii 2004, M. Balke & M. Monaghan (MD 011) (1 ZSMC); Sava: 13 km SW of Vohemar along RN5A, Fananbe River, Mananbery village, dried out sandy river, 13.4451S 49.9408S, elev. 20 m, 5 xi 2014, R. Bukontaite & J. H. Randriamihaja (MAD14-44) (1 NHRS); Mahajanga, Boeny: Ankarafantsika NP. S 16.31215 E 0 46.81523, 76 m. a.o. 29 XI 2009 Field # MAD09-02, 16° 18' S, 46° 48' E, J. Bergsten, N. Jönsson, T.Ranarilalatiana, HJ. Randriamihaja (MAD09-02) (2 NHRS); Boeny: Mahavavy Kinkony RS. S 16.14653 E 0 45.94926, elev. 9 m, 16° 9' S, 45° 57' E, 4 xii 2009, J. Bergsten, N. Jönsson, T. Ranarilalatiana, HJ. Randriamihaja (MAD09-24) (1 NHRS); Boeny: Mahavavy Kinkony RS. S 16.15502 E 0 45.91878, elev. 10 m, 16° 9' S, 45° 55' E, 3 xii 2009, J. Bergsten, N. Jönsson, T. Ranarilalatiana, HJ. Randriamihaja (MAD09-18) (17 NHRS); Toamasina, Andasibe, fish ponds at park entrance, elev. 910 m, 18° 46' S, 48° 24' E, 1 xi–30 xii 2004, M. Balke (MD 036) (1 ZSMC); Toliara, Andranomena, at black light, dry forest near open marsh, 19° 53' S, 45° 4' E, 30 iii 1990, W. E. Steiner, C. Kremen, V. Razafimahatratra (273 USNM); Menabe: Kirindy RS. S 20.07655 E 0 44.67532, elev. 57 m, 20° 5' S, 44° 41' E, 12 xii 2009, J. Bergsten, N. Jönsson, T. Ranarilalatiana, HJ. Randriamihaja (MAD09-47) (1 NHRS); Morondava, Kirindy Forest, small pond in dry river bed, N:-20.07250, E: 44.67150, elev. 19 m, 20° 4' S, 44° 40' E, 4 xi 2006, Isambert et al. (P56 Bio 2) (1 NHRS); Zombitse, PN Zombitse section Isoky, Andranomena R. near Ranomena, pools of muddy & veg.-rich waters in river basin, N:-22° 38.407, E:44° 51.866, elev. 578 m, 22° 38' S, 44° 52' E, 15 v 2006, Bergsten et al. (P42G) (3 NHRS).
Differential Diagnosis. Differentiated from A. plicicollis by the smaller size (ca. 1.20 mm vs. 1.34 mm), the shallower pronotal impressions, with the midlongitudinal impression almost obsolete, and the shorter and sparser dorsal pubescence. The aedeagi of the two species differ in shapes of the distal part of the main piece, in both ventral and lateral views (Figs. 212, 213).
Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.20/0.56; head width 0.33; pronotum 0.29/0.52; elytra 0.60/0.56. Dorsum black except hyaline borders of prothorax transparent.
Eyes with moderately coarse, convex facets. Frons with deep impressions, borders of impressions rounded, smooth; clypeus with very few, very shallow punctures, almost impunctate; labrum anterior margin arcuate in both sexes.
Pronotal relief very smooth, with very sparse and very short indistinct setae; anterior and posterior transverse impressions very shallow, anterior contiguous with shallow transverse impression immediately behind anterior margin of lateral lobe; median longitudinal impression very shallow, barely perceptible, extended from anterior impression to ca. midlength of disc. Pronotum lateral hyaline borders very wide, extended from posterior to anterior angles, outer margin strongly arcuate; sides behind lateral lobes with conspicuous setae immediately above hyaline border; sides of lateral lobes without any or only few inconspicuous setae; anterior hyaline border moderately wide.
Elytra very smooth, ten seriate-punctate, punctures very small and very shallow, each with indistinct seta, very short, only slightly longer than width of puncture; lateral margin with setae in anterior 1/2.
Males slightly smaller than females: males ca. 1.10–1.20 mm; females ca. 1.16–1.28 mm.
Etymology. Named in reference to the very smooth dorsum.
Distribution. Rather widely distributed in Madagascar (Fig. 305).
Remarks. In some specimens the aedeagus, when extracted by removing the abdominal terga, has the flagellum tightly looped in a "bundle." The flagellum of A. perlaevis is ribbon-like, and when uncoiled is totally flexible. The proximal end of the flagellum, which is inside the main-piece, appears to be "closed" and not connected with a duct. The gonopore might be at the distal end of the main-piece, not at the distal end of the flagellum. The flagellum, being ribbon-like, may serve as an adhesion device during copulation, not as a spermatophore transfer tube. The very small size of the aedeagus hinders a complete interpretation.
description: Published as part of Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), pp. 1-264 in Zootaxa 4342 (1) on pages 220-221, DOI: 10.11646/zootaxa.4342.1.1, http://zenodo.org/record/1041066