Cangshanaltica siamensis, Damaška, Albert & Konstantinov, Alexander, 2016

Damaška, Albert & Konstantinov, Alexander, 2016, A new species of Cangshanaltica Konstantinov et al., a moss-inhabiting flea beetle from Thailand (Coleoptera: Chrysomelidae: Galerucinae: Alticini), Zootaxa 4107 (1), pp. 93-97 : 93-95

Cangshanaltica siamensis new species

(Figs 1, 2)

Description. Habitus. Body length 1.94–2.21 mm, width 1.45–1.62 mm. Body oval in dorsal view, convex in lateral view. Upper side dark brown, without metallic lustre. Abdomen and legs lighter, chestnut brown (Fig. 1).

Head. Head nearly hypognathous. Vertex shiny, lacking wrinkles, with small, sparse punctures and few thin, scattered setae. Antennal calli poorly developed, triangular, their borders barely traceable. Supracallinal, midfrontal and suprafrontal sulci shallow, barely visible. Supraorbital sulcus deep and straight. Interantennal space wide. Labrum black. Maxillary palpomeres chestnut brown with yellow apices. Antennae with 11 antennomeres, antennomeres 1–4 yellow, continually darkening, antennomeres 5–10 brown, antennomere 11 lighter, yellowish-brown. Antennomere 7 with distal protrusion anteriorly. Antennomere 2 oval, ca. 1.4× longer than wide. Antennomeres 3 and 4 very thin, much thinner than antennomeres 1 and 2 each.

Thorax. Pronotum convex, in the middle 1.79 times as wide as long, with small and shallow, sparse punctures. Lateral margin with setiferous pore situated nearly in middle. Elytra convex, humeral calli absent. Punctation of elytra fine, but coarser than that of pronotum, punctation confused. Metathoracic wings not developed. Anterior coxal cavity open posteriorly. Third tarsomere of all tarsi long, as long or slightly longer than first tarsomere. Inner side of metatibia with a row of teeth situated between distal 1/4 and tibial apex. Metafemur pilose. Metatibial apical spine long, reaching ca. 4/5 of first metatarsomere.

Abdomen with 5 ventrites. Longitudinal ridge on first abdominal ventrite developed only basally and short, almost invisible. Metacoxal cavities very deep, reaching nearly mid length of the first ventrite.

Genitalia. Spermathecal pump long, receptacle narrow, slender. Vaginal palpi slender. Aedeagus long, curved in lateral view, parallel-sided from base nearly to apex, then converging apically. Orificium basale very long, arrow-shaped (Fig. 2).

Sexual dimorphism. Males generally smaller than females—male 1.94 mm long and female 2.21 mm long. Females with smoother frons, antennal calli less distinct than in males.

Differential diagnosis. We place this species in Cangshanaltica based on the following characters: anterior coxal cavities open posteriorly; setiferous pore placed nearly in middle of lateral pronotal margin; antennomere 7 with a distal anterior protrusion (Fig. 1); male genitalia more or less flat in lateral view with indistinct broad depression ventrally, sides parallel at basal half, gradually narrowing without well-defined denticle at apex (Fig. 2). The new species may be distinguished from C. nigra Konstantinov et. al., 2013 based on the following characters: third tarsomeres or all tarsi long (Fig. 2), as long or slightly longer than first (in C. nigra , third tarsomere is significantly shorter than first, especially on metatarsi), longitudinal ridge on first abdominal ventrite very short, present only basally and hence nearly indistinct (in C. nigra , the ridge is long) (Fig. 2), metatibial apical spine long, reaching ca. 4/5 of first metatarsomere (in C. nigra , metatibial apical spine reaches at most 1/2 of first metatarsomere), upper side of body dark brown (in C. nigra , the upper side is black with metallic lustre). Cangshanaltica siamensis can be also distinguished by the some features of male genitalia: parallel sides of aedeagus extend further apically, apex only very slightly bent ventrally (in C. nigra the bend is more pronounced).

Etymology. The name siamensis is derived from the old name for Thailand—Siam.

Type locality and ecology. Specimens of C. siamensis were collected by beating moss from tree trunks in a cloud forest in the summit area of Doi Inthanon, ca. at 2 500 m a.s.l. (Fig. 3). Specimens were collected in semi-dry moss during the dry season.

Type material. Holotype male. Labels: (1) THAILAND—Chiang Mai prov., Mae Chaem distr., Doi Inthanon, 18°35'10.36"N, 98°28'57.18"E, cloud forest in dry season, dry moss on trees, 6. iv. 2015, Albert Damaška lgt.; (2) HOLOTYPE Cangshanaltica siamensis sp nov., Albert Damaška and Alexander Konstantinov des. 2016. Paratypes have same labels as holotype. Holotype NMPC, paratypes: 1 female NMPC, 3 (1 male, 2 female) USNM, 2 (1 male, 1 female) ADPC.