Carchesiopygus Schedl, 1939 : 403

Beaver, Roger A. & Sanguansub, Sunisa, 2015, A review of the genus Carchesiopygus Schedl (Coleoptera: Curculionidae: Platypodinae), with keys to species, Zootaxa 3931 (1), pp. 401-412 : 403-404

Genus Carchesiopygus Schedl, 1939: 403 .

(Figs 1–10)

Type species: Crossotarsus wollastoni Chapuis, 1865: 74 . Original designation.

Diagnosis: The genus belongs in the tribe Platypodini ( Wood 1993, Alonso-Zarazaga & Lyal 2009). Carchesiopygus is distinguished from all African and American genera in the tribe, except the Neotropical Neotrachyostus Browne , and Afrotropical Trachyostus Schedl , and from the Oriental genus, Baiocis Browne , by the lack of armature on the anterior margin of the metasternal-metepisternal impression, and the presence of setae on the impression ( Wood 1993). The lateral emarginations of the pronotum in Carchesiopygus are angulate anteriorly only ( Browne 1962), with a carina on the upper margin in the anterior half only. This separates it from Neotrachyostus and Trachyostus , and from most other genera of Platypodini that occur in the Oriental and Australian regions, except Crossotarsus and a few species of Platypus . In other genera, the lateral emarginations of the pronotum are angulate posteriorly, or occasionally both anteriorly and posteriorly.

Carchesiopygus can be distinguished from Crossotarsus by the following characters ( Carchesiopygus characters listed first): 1) labial palps three-segmented, with separate basal segments vs labial palps twosegmented, with basal segments fused in the midline; 2) metacoxa not strongly projecting, with a shallow vertical posterior face vs metacoxa strongly projecting with a deep vertical posterior face; 3) male fourth abdominal ventrite with a pair of widely separated, ventrally projecting spines or flanges vs male fourth abdominal ventrite unarmed; 4) female pronotum with mycangial pores vs female pronotum without mycangial pores. The genus can be distinguished from those species of Platypus which have the lateral pronotal emarginations angulate anteriorly by the shallowly projecting metacoxae, the armature of the male fourth abdominal ventrite, and the sexually dimorphic protibiae.

Description. The genus has the following combination of characters. The body size is large, 6–9 mm in males, 6–10 mm in females. In both male and female, the eyes are oval, the antennal funicle four-segmented, the antennal club pubescent to the base. The lacinia and galea of the maxilla are fused. The labial palps are three-segmented, with separate basal segments. The lateral emarginations of the pronotum are carinate anteriorly, not posteriorly, and the anterior margin of the pronotum is wider than the posterior margin. The metasternum and metepisternum are weakly impressed near the metacoxae, the impressed part bears setae, and its anterior margin lacks any sculpture. The procoxae are contiguous and shorter than the protibiae. The metacoxa is not strongly projecting, and has a shallow, vertical posterior face. In the male, the frons is flat or almost so, and strongly punctured on much of its surface. The pronotum may or may not have mycangial pores. The apex of the elytral disc has a series of similar teeth or spines extending over the convex elytral declivity, which bears a small spine on each side near the apex and below interstriae 2–3. The posterior face of the tibia bears several oblique rugae. The fourth abdominal ventrite bears a pair of widely separated, ventrally projecting spines or flanges on or close to its posterior margin. The fifth abdominal ventrite is large and strongly concave. In the female, the frons is longitudinally impressed, and at least the central area is impunctate. The pronotum has one or more large mycangial pores, asymmetrically arranged in one species, and sometimes a small number of smaller mycangial pores behind the larger ones. The basal part of the protibia is granulate, the granules sometimes extending over most of the face, the apical part with 1–3 oblique rugae.

The genus is confined to the Oriental region, its range extending from Northern India and Southern China (Yunnan) through Southeast Asia to the Western islands of Indonesia. The genus is not known East of Wallace’s line ( Wallace 1876, Simpson 1977). The biology of the genus is essentially unknown, but is expected to be similar to other genera in the tribe ( Kalshoven 1960, Browne 1961, Schedl 1972, Beaver & Liu 2013). The gallery system has not been described. A few host records are available for some species (see below).

PLATE 1. Dorsal views of Carchesiopygus species. Figures 1–2. C.wollastoni Chapuis male and female. Scale line = 2 mm.