Phaelota Jacoby, 1887

Prathapan, K. D. & Konstantinov, A. S., 2009, Descriptions of eight new species of Phaelota (Coleoptera: Chrysomelidae) with a new generic synonymy and a key to species of Indian subcontinent, Zootaxa 1991, pp. 1-27 : 1-2

Genus Phaelota Jacoby

Phaelota Jacoby, 1887: 94 (Type species: Phaelota semifasciata Jacoby, 1887 , Sri Lanka, by monotypy); Maulik, 1926: 176; Chen, 1936: 659; Heikertinger and Csiki, 1940: 511; Scherer, 1969: 8, 18, 218; Seeno and Wilcox, 1982: 144; Prathapan and Viraktamath, 2004: 1–18 .

Thrylaea Jacoby, 1887: 98 (Type species: Thrylaea variabilis Jacoby, 1887 , Sri Lanka, by monotypy); Maulik, 1926: 284, 307; Chen, 1936: 659; Heikertinger and Csiki, 1940: 528; Scherer, 1969: 7, 233; Seeno and Wilcox, 1982: 144. New synonym.

Distribution. India, Sri Lanka, the Philippines and Borneo.

Diagnostic characters. Alate or apterous, 1.9 to 5.2 mm long, convex, ovoid, narrowed posteriorly. Antennal callus well developed, transverse to oblique, anteromesal end triangular and entering into interantennal space. Distance between eye and adjacent antennal socket subequal to transverse diameter of a socket or slightly less; distance between antennal sockets 1.5 – 4.7 times diameter of a socket and less than transverse diameter of one eye. Frontal ridge wide, widening anteriorly. Anterofrontal ridge lower than frontal ridge, flat. Labrum with a transverse row of four setiferous punctures. First antennomere as long as next two combined, last five or six antennomeres thickened. Pronotum transverse, 1.3 – 1.8 times wider than long, with poorly developed antebasal transverse impression delimited on either end by curved longitudinal impressions. Procoxal cavity closed behind. Prosternum broad. Elytra as wide as prothorax at base, widening at humerus. Elytral punctures arranged in striae. Epipleuron moderately wide, reaching beyond 4/5 th of elytron. Dorsal surface of metatibia more or less flat. Metabasitarsus slightly longer than next two tarsomeres combined. In repose, metatibia received over a longitudinal ridge along mesal side of metafemur, edge of this ridge being distinctly serrulate in male.

Remarks. Though described in the same paper, Jacoby (1887) did not compare Phaelota with Thrylaea as in the case of Ivalia and Amphimeloides ( Duckett et al., 2006) . A syntype of Thrylaea variabilis Jacoby was examined and found to be a typical alate Phaelota with all the salient features of the genus including the serrulate metafemur in the male. No significant character separates it from P. semifasciata Jacoby or other congenerics. Hence Thrylaea is synonymised with Phaelota and as both the names were published in the same paper, we here give precedence to Phaelota .