Hexacylloepus tibialis, Polizei & Barclay & Bispo, 2020

Polizei, Thiago T. S., Barclay, Maxwell V. L. & Bispo, Pitágoras C., 2020, Hexacylloepus Hinton, 1940 rises again; 18 new species of a neglected genus (Coleoptera: Byrrhoidea: Elmidae), Zootaxa 4819 (1), pp. 6-48 : 40-42

Hexacylloepus tibialis sp. nov.

( Fig. 16 A–C)

Type locality: Brazil, São Paulo State, Cunha .

Diagnosis: Antennae without setae. Frontoclypeal suture short and straight. Pronotum with sublateral carinae not reaching the anterior margin and with a long, narrow and shallow longitudinal impression on disc, reaching the anterior and posterior margins. Elytra without carinae. Hypomera with a dense belt of tomentum reaching only the lateral margin. Epipleura covered with tomentum. Tibiae very long, each with a row of spines and setae on distal half. Abdomen with the disc of the first and second ventrite without tomentum and with a depression on the disc of the first. Male genitalia with the phallobase twice as long as wide; parameres half as long as the penis, with apex slightly sharp and curved to internal margin; penis constricted at base, with the lateral margin sinuous, anterior half slightly narrowed.

Description: Male. Body elongated, subparallel. Black colour, with the antenna, mouthparts and legs reddishbrown. Total length: 3.27 mm. Greatest width: 1.68 mm.

Head: surface with micropunctures. Antenna inserted between the anterior margin of the eyes and the frontoclypeal suture, filiform, with 11 antennomeres without setae. Frontoclypeal suture short and straight. Clypeus 3x as wide as long; anterior margin concave and posterior sinuous; surface similar to that of head. Labrum twice as wide as long; antero-lateral angles rounded and alutaceous; surface with short and thin setae. Maxillary palpus 4- segmented; terminal palpomere truncated apically. Labial palpus 3-segmented. Mentum and submentum squared. Gula rectangular. Genae covered with tomentum.

Thorax: Pronotum as long as wide, arcuate anteriorly; sides arcuate, posterior margin smooth with two prescutellar foveae ( Fig. 16A ). Surface with micropunctures, disc raised. Sublateral carinae, sinuous, raised and reaching only 2/3 posterior of the pronotum ( Fig. 16A ). Longitudinal impression long, shallow and deep on disc, reaching the anterior and posterior margin.

Elytra twice as long as wide; anterior margin arcuate, lateral margin moderately arcuate; rounded apex ( Fig. 16A ). Humeri rounded and prominent. Surface with puncture rows and without carinae. Elytral suture moderately elevated. Epipleura covered with tomentum ( Fig. 16B ). Hind wings macropterous. Scutellum oval.

Prosternum as long as wide, surface with micropunctures, anterior margin straight and sides covered with tomentum. Prosternal process broad and long, and beyond the procoxae; lateral margin slightly elevated; rounded apex. Notosternal suture slightly sinuous. Hypomera wider posteriorly than anteriorly, surface with micropunctures and with a dense belt of tomentum reaching the anterior and lateral margins ( Fig. 16B ).

Mesoventrite with a groove to receive the prosternal process. Mesepimeron and mesepisternum covered with tomentum. Metaventrite broad with a longitudinal medial depression; surface with micropunctures and with sides covered with tomentum.

Legs (except tibiae and tarsi) covered with punctures and tomentum ( Fig. 16B ). Coxae strongly rounded; Trochanter elongated; femora long, 7x longer than wide, slightly constricted at apex, with half of the elytra length; tibiae very long and thin, 14x as long as wide, 2/3 of the elytra length, and with two rows, one of setae and other of spines in the distal half. Profemora each with a row of short golden setae on proximal half. Tarsi elongate, with setae; apical tarsomere with the length of the basal four combined. Claws long and thin.

Abdomen ( Fig. 16B ): five ventrites; slightly as wide as long. Anterior and posterior margins straight on the first and second ventrites and arcuate on the subsequent ventrites, lateral margins rounded. Surface densely covered with tomentum and long setae (excepted for disc of first and second ventrite). First ventrite with a slight depression on disc. Fifth ventrite with lateral margins slightly produced posterolaterad, apex tapered and with long golden setae on posterior half.

Male genitalia ( Fig. 16C ): (Total length: 1.31 mm. Greatest width: 0.41 mm), symmetrical. Phallobase twice as long as wide, approximately 1.5x longer than penis length. Parameres articulated with the phallobase, with half of the penis length; 4x wider on base as at the apex; apex slightly sharp and curved to internal margin. Penis constricted at base and with the lateral margin strongly sinuous; anterior half slightly sharp; fibula elongated with the approximately 2/3 of the penis length and of half of the penis’s width; corona present, arrangement of arrow-like sclerotizations.

Female: External morphology similar to male, except fifth abdominal ventrite with a groove at apex and without setae.

Material examined: 9 specimens.

Distribution: Brazil: São Paulo State.

Male holotype: ♂ | Holo- / type | BR-SP-Cunha / P.E.S.M núcleo Cunha / 25.VII.2012 / T.T.S.Polizei & / L.S.M.Costa leg. | MZSP 35766 (MZSP) .

Paratypes: 8 specimens (2 ♂ 6 ♀): Para- / type | BR-SP-Cunha / P.E.S.M núcleo Cunha / 25.VII.2012 / T.T.S.Polizei & / L.S.M.Costa leg. (1 ♂ 1 ♀ MZSP; 1 ♂ 2 ♀ NHMUK) . ♀ | Para- / type | BRASIL. São Paulo. Campos do / Jordão. Parque Estadual Campos / do Jordão. 07.VII.2013 1542m / 22°41’31,2”S 045°29’28,8”W / Thiago Polizei & Lucas Costa leg. (2 ♀ MZSP). (MZSP 31164-31165; 35765-35767) . ♀ | Para- / type | BR—SP—P. N. Bocaina / São José do Barreiro—Rio / Piricaba ( Est. Do Pico Tira / Chapéu )— 20-21.VIII.2015 / Ferreira-Jr, Dumas, Sampaio, / Guimarães, Vieira (DZ/UFRJ) .

Etymology: tibialis is a reference to the very long tibiae.

Comparative notes: Hexacylloepus tibialis sp. nov. can be easily differentiated from all other species of Hexacylloepus by the absence of carinae on elytra and tomentum on tibiae.

Figures

FIGURE 16. Hexacylloepus tibialis sp. nov.. Male. Holotype. (A–B) Habitus. (A) Dorsal view. (B) Ventral view. (C) Ventral view of male genitalia. Scale bars: (A–B) = 0.5mm. (C) = 0.1mm.