NEW TRIBE OF CHAFERS FROM VIETNAM (COLEOPTERA, SCARABAEIDAE, MELOLONTHINAE)

Abstract

A new genus and two new species of Melolonthinae are described from Dalat Highlands of Vietnam at altitude 750-800 m. Together with the monotypic genus Pseudoisonychus Frey, 1971 it is separated in the new tribe Langbianellini. Diagnoses of the new taxa: Langbianellini trib. n.: Labrum horizontal, on the same plane with clypeus to forming labroclypeus; maxillae with a long pubescence reminiscent a “sucking brush” of Valgines; antennae 8- or 10-articulated, with small 3-jointed club; anterior margin of pronotum with membranous border; propygidium strongly enlarged and inflated, fused with 5th sternite; pygidium reduced; metacoxae narrow, legs gracile; metatibial spurs closely spaced, attached below metatarsus; claws symmetrical. Langbianella g. n.: Antennae 8-joined, 3rd joint of club somewhat reduced in size, with a slit-like stripe of microsensillae; anterior margin of labrum concave; pronotum broadest at base; elytrae with 10 striae, all reaching to apex; body with a specialized setosity; all claws splitting. L. auricomes sp. n.: simple punctures between the setigerous punctures of pronotum very fine and sparse, umbilicate punctures lacking setae present at the lateral thirds of the pronotal base only; punctate rows of elytra with simple hairs; basal two-thirds and apical part of the 1^st elytral interspace with patches of very long bright erect hairs in several rows; elytrae, pygidium and propygidium without microsculpture; pygidium uniformly covered with setigerous punctures; scutellum with sparse and irregular small punctures; middle third of 5th abdominal sternite uniformly covered with umbilicate setigerous punctures; abdomen reddishbrown. L. pterolepis sp. n.: simple punctures between the setigerous punctures of pronotum dense and rough, umbilicate punctures lacking setae present at the posterior part of the pronotal disc and along the pronotal base; punctate rows of elytra together with an additional punctate row in each of the odd interspaces bearing the modified dorsally expanded setae; elytrae, pygidium and propygidium with rough shagreen-like microsculpture; pygidium with bald medial stripe; scutellum with sharp and confluent puncturation; middle third of 5th abdominal sternite with a single row of umbilicate setigerous punctures near its distal edge; abdomen black.