Baeosega humida Krombein 1983

Baeosega humida

Baeosega humida has been found in or on leaf litter only on the highest ridge of Udawattakele Sanctuary, Kandy, in the Wet Zone at an altitude of 600 m, where the average annual rainfall is 1950 mm. It is known from both sexes, and occurs in the same areas as B. laticeps, new species, which is known only from females. Females of those two species are readily separated from those of B. torrida, new species, by the lack of delicate rugulae on the declivous anterior surface of the first metasomal tergum, the glossier first and second terga with less conspicuous suberect vestiture, and in having the legs partly to predominantly dark brown or black rather than light red and testaceous. Females of B. humida and B. laticeps are very similar to each other, differing chiefly in cephalic and thoracic indices as follows: in the former species the head width is 3.1–3.3 times the least interocular distance (Figure 56), the head is narrower in proportion to dorsal length (1.4–1.6:1), the upper front is straight or slightly protuberant between the eyes, and the pronotal length and width are subequal, whereas in the latter species the head width is 2.8–2.9 times least interocular distance (Figure 57), the head is broader in proportion to the dorsal length (1.7–1.9:1), the upper front is slightly concave between the eyes, and the pronotal length is 0.8 times the width. The abdomen is more weakly chitinized in females of B. humida than in those of B. laticeps; the sides of the second metasomal segment are always partially collapsed in the former species but not at all deformed in the latter. Males of B. humida are less erythristic than those of B. torrida, especially on the dorsum of the head and thorax, the head is comparatively narrower than the least interocular distance (1.80–1.96 as compared to 1.93–2.04), and the pronotal width at the lobes is comparatively narrower than median length (usually 1.05–1.30 as compared to 1.36–1.41).

HOLOTYPE.—; Sri Lanka, Central Province, Kandy District, Kandy, Udawattakele Sanctuary, 1800 ft (547 m), 23–25 Sep 1980, on or in leaf litter, K.V. Krombein, P.B. Karunaratne, L. Jayawickrema, V. Gunawardane, P. Leanage (USNM Type 100454).

FEMALE.—Length 2.4 mm. Black, the following light red: mandible except tip, scape, pedicel, first three flagellar segments, anterior and lateral margin of pronotum, prosternum, upper half of mesopleuron, lower half of posterior propodeal surface, undersides of femora and tibiae, and tarsi; coxae partially and trochanters wholely testaceous; the following light to dark brown—pronotum, postscutellum, lower half of mesopleuron, propodeum except lower half of posterior surface, upper surface of femora and tibiae, and declivous surface of first metasomal tergum. Vestiture silvery to cinereous, erect setae on head, thoracic dorsum, legs and metasomal dorsum relatively short and sparse, most of that on side of thorax dense and suberect, that on abdomen suberect to subappressed but sparser than in B. torrida.

Head with characters of the genus and the following: width only slightly greater (1.06) than distance from apex of clypeus to posterior ocelli, and 2.9 times interocular distance at anterior ocellus; viewed from above (Figure 56) head 1.6 times length, upper front slightly protuberant.

Thorax with characters of the genus and the following: pronotum as long as greatest width and 1.5 times as long as combined lengths of scutum and scutellum, the latter 0.7 times as long as scutum and 0.6 times as long as postscutellum; posterior surface of propodeum with transverse rugulae which carry over onto posterior part of lateral surface.

Abdomen with characters of the genus and the following: Declivous surface of first metasomal tergum smooth; surface of terga glossy, vestiture sparser and less conspicuous than in B. torrida; second laterotergum collapsed inward.

ALLOTYPE.—; same location as holotype, 21–22 Sep 1980, K.V. Krombein, P.B. Karunaratne, T. Wijesinhe, L. Jayawickrema, V. Gunawardane (USNM).

MALE.—Length 2.6 mm. Black, the following light red: Mandible except apex, clypeus, front to level of anterior ocellus, malar area, scape, pedicel, first two flagellar segments, lateral surface of pronotum, mesopleuron except infuscation near lower margin, legs except tarsi, declivous surface of first metasomal tergum, first and second lateroterga, and first and second sterna; remainder of flagellum and tarsi brown. Vestiture short, silvery, subappressed except light brown and erect on flagellum. Wings slightly infumated, costa, radius, and stigma dark brown, other veins light brown.

Head with characters of genus and as follows: width twice interocular distance at anterior ocellus and 1.8 times distance from clypeal apex to posterior ocelli; ocelli in a higher triangle than in B. torrida, ocellocular distance 0.36 times postocellar distance and 0.57 times lateral ocellar distance.

Thorax with characters of genus and as follows: pronotum 0.7 times as long as wide and 0.7 times as long as combined lengths of scutum and scutellum; latter sclerite half as long as scutum, and subequal in length to postscutellum; mesopleural pits large, shallow, some of them subcontiguous but others separated by half the diameter of a pit.

Abdomen with characters of genus and as follows: most punctures on disk of first and second terga separated by about half the diameter of a puncture; second laterotergum collapsed inward.

PARATYPES.—All USNM; 30, 6, same locality as holotype, other data as follows: 7, 1, same label data as holotype; 5, 1, same data as allotype; 6, 2, 600 m, 12–14 Oct 1980, K.V. Krombein, P.B. Karunaratne, T. Wijesinhe, L. Jayawickrema, V. Gunawardane; 1, 22 Mar 1981, K.V. Krombein, T. Wijesinhe, L. Weeratunge; 12, 1, 25–27 Apr 1981, same collectors as preceding. Paratypes of both sexes will be placed in the Colombo and British museums.

Female paratypes are 2.3–2.7 mm long. There is an extensive range of color variation in B. humida, the holotype being representative of the darkest phase. The most erythristic individuals have the following light red in addition to that noted for the holotype: pronotum except infuscated blotch across middle, entire mesopleuron, postscutellum, propodeum, femora, and hind tibia. Other variations from the holotype are as follows: head width 1.04–1.13 times distance from clypeal apex to posterior ocelli, and 2.7–3.0 times interocular distance at anterior ocellus; viewed from above, head 1.4–1.6 times length; pronotal length 0.9–1.0 times greatest width and 1.5–1.8 times as long as combined lengths of scutum and scutellum, the latter 0.5–0.8 times as long as scutum and 0.4–0.6 times as long as postscutellum; and the side of the second metasomal tergum may be collapsed inward as well as the laterotergum.

Male paratypes are 2.3–2.7 mm long. There is relatively little variation in the color pattern as follows: temple, posterior occiput, and posterior margin of pronotal disk may be light red, and mesopleuron may be infuscated. Other variations are as follows: head width is 1.8–2.0 times interocular distance at anterior ocellus and 1.6–1.7 times distance from clypeal apex to posterior ocelli; pronotal length 0.8–0.9 times width and 0.7–0.8 times combined lengths of scutum and scutellum; latter sclerite 0.4 times as long as scutum and 0.9–1.1 times as long as postscutellum.