Alasia Furth and Zhaurova

Furth, David G. & Zhaurova, Kira M., 2010, Two new flea beetle genera: Alasia alpina gen. et sp. nov. from a Costa Rican cloud forest and Pseudostenophyma gen. nov. from Brazil (Coleoptera: Chrysomelidae: Alticinae), Zootaxa 2679, pp. 32-50 : 33-34

Alasia Furth and Zhaurova , new genus

Type species: Alasia alpina Furth & Zhaurova , new species

Description. Body shape elongate narrow. Dorsal punctation generally medium-sized, sparse to moderately dense. Body length: 2.85–4.0mm.

Head: ( Figs. 1 a–c; 4a–b): Narrowed posteriorly (at base, in dorsal view); antennal calli distinctly delimited, especially posteriorly; antennae as long as entire body; frons in frontal view wide, broadly triangular, evidently expanded ventrally, in lateral view vertex and frons forming a 90° angle, frons strongly concave; vertex with medium-sized, sparse punctuation; eyes large, round, prominent, but total width (eye to eye) across head not apparently greater than pronotal anterior width, distance between inner eye margins broad (see measurements in species description); dorsal punctures sparse, medium-sized; labrum bearing four fine setiferous punctures on dorsal surface, two on each side.

Pronotum: ( Figs. 1 a; 4c): Evidently narrowed at base (posteriorly); antero-lateral callosities (sensu Konstantinov 1998) not distinctly angled, only with slight sub-quadrate enlargement with setiferous pore; distinct pre-basal transverse impression, especially medially, not distinctly delimited laterally; dorsal punctation medium-sized, sparse, unevenly distributed.

Elytra: ( Figs. 1 a–b, 4c): Parallel-sided; base distinctly wider than base of pronotum; humeri prominent; postbasal transverse depressed area creating basal, raised elytral bossae (calli); punctation confused medially but with some evident striae in middle and laterally, epipleura parallel-sided, equal width from near base to just before tapered apex, mostly smooth. Two baso-lateral patches of microspines on underside of each elytron adjacent to epipleuron ( Fig. 4 d), i.e., binding patches (sensu Samuelson 1994).

Venter: Procoxal cavities open ( Fig. 1 d). [see description below of the type species for characters of the thoracic and abdominal sternites]

Legs: Moderately long with spindle-shaped femora, metafemora swollen distinctly more so than pro or mesofemora, but not greatly swollen or fat. Metafemoral spring ( Fig. 3 c) with dorsal lobe only gently arched - more or less straight, extended as extended arm significantly beyond ventral lobe, extended arm about 25% of total spring length, extended arm gradually depressed apically, basal angle of ventral lobe, dorsal edge of ventral lobe descending only gradually towards apex, sclerotized recurve flange evident; spring belongs to the Phyllotreta Morpho-group ( Furth & Suzuki 1998). Metatibiae with distinct sclerotised apical spine, pro and meso-tarsi with very small apical spur (almost not evident); Metatibial apex not unusually expanded or laterally compressed, with dorsal margins of extreme apex with stout spines, a distance subequal to length of tarsomere 2. First metatarsomere relatively long, almost as long as tarsomeres 2–5 combined; male first protarsal segment only slightly swollen; claws appendiculate.

Remarks. Alasia is most similar to Pseudo s tenophyma Furth (described below) because of elongate somewhat parallel-sided elytra, shape of head in lateral view (90° angle of vertex/frons and frons concave), antennae as long as entire body, prominent, large round eyes, pronotal pre-basal transverse impression, procoxal cavities open, presence of frontal calli and elytral bossae (calli); male with first protarsal segment not distinctly swollen. However, Pseudo s tenophyma differs from Alasia in the following characters: frons narrow in shape, parallel-sided, ventrally tapered in frontal view; anterolateral callosities of pronotum distinctly angled; pronotal prebasal transverse impression evidently delimited laterally by short, longitudinal, sub-lateral carinae; pronotum quadrate or rectangular in shape, not evidently narrowed basally, with sides straight and parallel-sided; eyes larger, IOD smaller; gena laterally below eye narrower; dorsal punctation of head, pronotum more coarse, dense; elytral punctuation striate; antennal segment 3 significantly shorter than 4; pro and mesotibial apical spines very apparent; metafemoral spring shape differs (see descriptions); head shape broader basally/posteriorly.

The genus Nasigona Jacoby is morphologically rather similar to Alasia but differs in having closed procoxal cavities, elytral pubescence, no elytral bossae, different pronotal shape, not narrowed basally and not having angled lateral margins, smaller eyes, considerably finer dorsal punctation throughout. Leptophysa Baly is also somewhat similar to Alasia, but differs by having pubescent elytra, no elytral bossae, pronotum laterally with straight parallel lateral margins not evidently narrowing at base, procoxal cavities closed, antennae not reaching to the apex of elytra, pronotal pre-basal transverse impression clearly delimited sublaterally by short longitudinal carina, head in lateral view with frons and vertex not at a sharp 90° angle and frons not strongly concave, eyes not bulging,

Etymology. Named for the Project ALAS (Arthropods of La Selva) at La Selva Biological Station, Heredia, Costa Rica, as a random combination of letters to be treated as feminine.

Figures

FIGURE 1. Alasia alpina: a) dorsal habitus view; b) lateral habitus view; c) frontal view; d) procoxal cavities.

FIGURE 3. Alasia alpina: a) female spermatheca; b) female vaginal palpi; c) metafemoral spring.

FIGURE 4. Alasia alpina: head [SEM] a) vertex; b) frons; c) pronotum & elytra; d) elytral patches.