Hylomesa longiceps (Turner 1918)

Hylomesa longiceps (Turner)

Plesia tricolor (Smith).—Magretti, 1892:258, 259 [in part, misidentified from Burma].—Turner, 1908a:408 [misidentified from Assam].

Myzine tricolor (Smith).—Bingham 1897:66 [misidentified from Assam].

Elis (Mesa) tricolor (Smith).—Turner, 1912:720 [in part, misidentified from Assam and W India].

Elis (Mesa) tricolor longiceps Turner, 1918:87 [, Dibrughur, Assam; type in British Museum].—Rohwer, 1921:90 [, ; Philippines].

Mesa tricolor longiceps (Turner).—Guiglia, 1965:315 [, Ceylon].—Baltazar, 1966:207 [Philippines].

Hylomesa longiceps (Turner).—Krombein, 1968:12–15, fig. 1, pl. 1: fig. 1 [, ; Ceylon, India, Assam, Burma, Malaysia, Philippines].

This handsome species is readily distinguished from its only Ceylonese congener, H. anomala, new species, by the characters listed in the foregoing key. All species of the genus are collected rather uncommonly, and I suspect that this is due to their being primarily arboreal creatures. Presumably they prefer to parasitize beetle prey in dead standing timber rather than in wood on the ground.

Hylomesa longiceps is noteworthy in that it is the most widely distributed species of the genus with records of capture in Sri Lanka, India, Assam, Burma, Malaysia, and the Philippines. Within Sri Lanka it occurs both in the Dry Zone forests and in areas of moderate rainfall.

It is also the only Hylomesa for which we have any information on host preferences. Turner (1912) stated that T.R. Bell “informed me that he bred this species from the larva of a longicorn beetle.” This statement is at variance with the label data on the only female H. longiceps bearing a Bell label: “in dead wood with longicorn larvae 14–1–07.”

FEMALE.—Length 15–23, forewing 10–16 mm. Black, head except apex of mandible and hypostomal area and occasionally the ocellar triangle, varying from light to dark red; scape, pedicel, and from 1 to 4 of basal flagellar segments also red; abdomen occasionally with metallic blue reflections; forewing entirely infumated or with basal area lighter in some specimens, the darkened area with violaceous reflections.

Head elongate, from above with length (apex of antennal insertions to occiput) subequal (0.94–1.0) to width across eyes; in larger specimens the sides of head are somewhat rounded out behind eyes so that eyes are not so protuberant as in smaller specimens; clypeal keel weak, present only on basal half or two-thirds, clypeal margin with median teeth weak, slightly separated; median frontal sulcus extending halfway to anterior ocellus; front with punctures moderate in size and contiguous or almost so; vertex with more scattered punctures on anterior third and almost impunctate on posterior two-thirds; ocellocular distance 2.17–2.43 times the postocellar distance and 0.42–0.44 times the ocelloccipital distance; anterior ocellus closer to apices of antennal tubercles than to occiput; head beneath with rounded posterolateral angles; distance between occipital and hypostomal carinae subequal to length of hypostomal area.

Anterior margin of pronotal disk strongly ridged, anterior half with coarse, confluent to subconfluent punctures arranged in longitudinal rows; scutum with subconfluent, coarse punctures except posteriorly somewhat more crowded; scutellum with punctures separated by half or more the diameter of a puncture but more crowded posteriorly; inferior margin of hind femur obtusely angulate near apex; apex of hind tibia on inner surface without heavy, flattened, short setae; punctures small on areas adjacent to cuneate space on propodeum, the disk posteriorly and laterally with larger, subconfluent pits; posterior surface of propodeum with mostly confluent or subconfluent pits.

Disk of first tergum strongly ridged anteriorly; last tergum shagreened on apical fourth.

MALE.—Length 12–17 mm, forewing 7–12 mm. Color as in female except that venter of head occasionally is all black and as many as 6 flagellar segments may be red.

Clypeal keel strong, present on basal two-thirds or three-fourths; median lobe of clypeus with a shallow emargination separating the 2 well-developed teeth; distance from apex of frontal platform to occiput 0.85–0.87 times the width across eyes; front with mostly contiguous to subcontiguous pits; vertex with smaller, more scattered punctures; ocellocular distance 1.9–2.8 times the postocellar distance and 0.59–0.71 times the ocelloccipital distance; occipital carina weak or evanescent dorsally; median flagellar segments 1.4–1.5 times as long as wide.

Pronotal disk anteriorly with a strong ridge, behind that with weak to strong punctures, sometimes rather scattered, sometimes arranged almost contiguously in a few transverse rows; scutum and scutellum with coarse, shallow, contiguous to subcontiguous pits; mesopleural disk with very coarse, contiguous to scattered pits; metapleuron usually without ridges above but occasionally with a few weak ridges; propodeal dorsum irregularly rugulose, the narrow median channel with a few transverse rugae, the posterior margin strongly ridged; lateral surface with a few strong rugae anteriorly, the rest of surface with coarse contiguous pits or irregularly rugulose; posterior surface varying from contiguously pitted to irregularly rugulose.

First tergum with strong transverse ridge anteriorly, the disk with scattered large punctures; sterna 3–5 with short, erect, relatively dense vestiture, but not velvety on sterna 5 and 6; genitalia (Figure 39) with gonostyle and cuspis broad, inner surface of each densely setose, digitus also broad and densely setose.

SPECIMENS EXAMINED.—NORTHERN PROVINCE. Vavuniya District: 1, Mamadu, Apr (Colombo).

EASTERN PROVINCE. Amparai District: 1, Ekgal Aru Reservoir Jungle, 100 m, 11 Mar, Wijesinhe (USNM).

CENTRAL PROVINCE. Kandy District: 1, Kandy, 20 Nov, Keiser (Basel).

UVA PROVINCE. Monaragala District: 1, Inginiyagala, 31 Aug, Keiser (Basel).

MISCELLANEOUS. 1, 1, no label (Colombo); 1, Ceylon, Nietner (Berlin); 1, Ceylon (Budapest).