Shillukia ribesi, Pluot-Sigwalt & Magnien, 2011

Shillukia ribesi n. sp.

( Figs. 1-3)

Type material:

HOLOTYPE: ♂: Côte d’Ivoire, 19.06.65, Galerie Bandama , 150 m 2, Gillon, Museum Paris. ( MNHN) .

PARATYPES: 7 ♂♂, 8 ♀♀, same data as holotype ( MNHN) ; 1 ♀, same data (coll. Magnien) ; 1 ♂, 1 ♀, Côte d’Ivoire, Lamto ( Toumoudi ), 12.02.1975, R. Vuattoux ( MNHN) .

Description:

Body elongate oval, coloration dark fuscous, shiny, antenna lighter.

Measurements (in mm): total length = 9.1-11.1 (♂), 9.3-10 .6 (♀); width = 4.7-5.9 (♂), 4.9- 5.5 (♀); ocular index = 2.4-2.7; interocellar index = 3.7-4.2.

Head ( Fig. 1a). Genae coarsely punctate, anteclypeus and middle part of frons less punctate. Clypeus wrinkled, as long as the paraclypei and devoid of subapical pair of setae; paraclypei almost converging in front, bearing three submarginal pairs of hair-like setae. Eye devoid of apical seta; ocelli located posteriad to the eye, at about one ocellar diameter behind a line connecting hind margin of the eyes. Antenna five-segmented slightly shorter than head and pronotum together, first segment shorter, second and third subequal, fourth longer by more than 50% than second, fifth two times as long as second. Rostrum just reaching the mesocoxae, the first segment not longer than the head and completely concealed between the bucculae in lateral view.

T h o r a x. Pronotum coarsely punctate, except in some areas, particularly on the calli and the hind margin finely punctate or impuctate; lateral margins almost straight in posterior two thirds, bearing six pairs of submarginal hair-like setae (five on the anterior half, one on the posterior half); scutellum triangular about as long as wide, the punctation stronger on the anterior part. Hemelytron slightly longer than the abdomen, almost completely covering the dorsum; its lateral margin elevated in the anterior half, bearing a single pair of marginal hair-like setae; corium overall punctate; membrane light fuscous. Legs reddish brown. Evaporatorium widely expanded on meso- and metapleuron ( Fig. 1b); vestibule elevated, relatively short, reaching about the middle of the evaporatorium, its surface wrinkled (gyrification); terminal lobe developed; ostiole opening caudad, just in front of a minute light brown process (peritreme?) ( Fig. 1b).

Abdomen. Sternites shiny, finely punctate laterally, smooth and impunctate in the middle; one pair of submarginal setae on sternites 6 and 7 each.

M a l e g e n i t a l i a. Parameres as in Figs. 1c, 2b. Phallotheca strongly sclerotized and pigmented, nearly straight showing three distinct protruding conjunctival processes ( Fig. 1d): the lower one trilobed and semimembranous ( Fig. 2a); the upper one membranous with a basal lobe; a triangular sclerotized, strongly pigmented structure consisting of the fine vesica closely flanked by a pair of finger-like processes situated between the upper and lower processes.

Fe m a l e g e n i t a l i a. External genitalia: see Fig. 1e; laterotergites 8 joined medially by a narrow dorsal bridge; laterotergites 9 bearing four long setae. Internal genitalia ( Fig. 3a): spermatheca lightly yellowish-pigmented, not strongly sclerotized; apical receptacle pear-shaped; intermediate part long, delimited by two well developed flanges; flexible zone lightly swollen in basal position; spermathecal duct wide, very long, coiled in a dense huge mass ( Fig. 1f), devoid of definite dilation or invagination, but clearly wider in apical part than in basal part. Spermathecal opening situated under a small pouch of the vaginal wall. Ring sclerites present, thin, associated with a pair of lateral vaginal pouches well differenciated ( Fig. 3a, arrows).

NOTE: The apical receptacle is usually positioned on the left of the large mass of the spermathecal duct. In one specimen it was located on the right. The twists and turns of the very long duct do not seem tidy and apparently do not follow a precise direction.

Etymology: It is our pleasure to dedicate this new species to our friend and colleague Jordi Ribes, in recognition of his very important contribution to the knowledge of Heteroptera.

Distribution: Ivory Coast.

Type locality and habitat: The concise labels of the holotype and most paratypes do not allow a clear localisation of the type locality, so we want to add here the following precisions. The specimens have been collected by Dominique Gillon in the «Station d’Ecologie de Lamto» (6°13 N, 5°02 W). The Lamto region is a forest-savannah mosaic area; the surface indicated, « 150 m 2 », represents very likely the area of the quantitative quadrat prospected by D. Gillon when she collected the specimens during 1965 (see Gillon, 1972). The words «Galerie Bandama» means that the specimens were collected in the gallery-forest of the river Bandama. We can thus deduce that S. ribesi n. sp. is probably a forest species rather than a savannah one.

Discussion:

S. ribesi n. sp. can be readily distinguished from S. polita by several characters: body size and shape, chetotaxy, punctation, position of the ocelli, shape of spermathecal duct ( Figs. 3 a-b) (see Table 1 View TABLE ).

The unusual structure of the spermathecal duct devoid of definite dilation or invaginated part, already described by Linnavuori (1977) in S. polita, is confirmed for the genus. All other features show no notable particularity and are clearly generally geotomine-like, including the female genital tract that possesses the paired ring sclerites of the parieto-vaginal glands associated with paired lateral vaginal pouches ( Fig. 3a).