Dichelocentrum ornatifrons, comb. nov.
Creators: name: Gapon, D. A.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Miridae
Dichelocentrum
Dichelocentrum ornatifrons

description: 3. Dichelocentrum ornatifrons (Odhiambo, 1959) comb. nov.
(Figs 19 M; 33 B–E; 35 A–H; 36 B, G; 37 A–C; 38 C; 42 D–F)
Polymerus (Poeciloscytus) ornatifrons Odhiambo, 1959: 37–40.
Polymerus xerophilus Linnavuori, 1975: 47, fig. 30, syn. n.
Material examined. Paratypes. “ Uganda Kawanda 5 iii 1958 At light T.R. Odhiambo ” “Pres by Com Inst Ent B M 1959-499” “ Paratype ♂ Polymerus (Poeciloscytus) ornatifrons sp. n. T.R. Odhiambo det.”, 1 male *; “ Uganda Kawanda 5 vi 1958 at light T.R. Odhiambo ” “Pres by Com Inst Ent B M 1959-499” “ Paratype ♂ Polymerus (Poeciloscytus) ornatifrons sp. n. T.R. Odhiambo det.”, 1 male *; “ Uganda Kawanda 13 iii 1957 Under Cofee J.Y. Omiat ” “Pres by Com Inst Ent B M 1959-499” “ Allotype ♀ Polymerus (Poeciloscytus) ornatifrons sp. n. T.R. Odhiambo det.”, 1 female * (BMNH).
Additional material. Tanzania, Mlingano, 19 Jan.1964, L. Trap, coll. I.A.D. Robertson, 1 male * (AMNH). “Somalia nr. Hargeissa 25–28.VI.63 Linnavuori”, red lable “ typus ”, 1 female * (AMNH).
Diagnosis. Recognised by following combination of characters: first antennal segment basally or entirely dark, femora yellowish-brown, with small or large dark brown spots, cuneus often red, veins on membrane often with red patches. These characters except the last one are peculiar also to some specimens of D. transvaalicum sp. nov., but it often has a few dark spots on pronotum, separated by pale spaces or at least medial pale strip, varying from full to very short. Males of D. ornatifrons recognised by relatively long and rather wide hypophysis of right paramere and absence of tubercle under it; relatively short hypophysis of left paramere with straight inferior margin and low carina on internal (right) wall; T-shaped posterior right lobe with long right branch and short left one on inflated vesica. D. transvaalicum has similar parameres but inferior margin of its left paramere hypophysis distinctly convex.
Redescription. Length 3.95–4.15 in males and 4.35–4.75 in females. Body covered with goldish or silvery thickened setae (Fig. 42 D–F).
Dorsal surfaces of head and pronotum dark brown to black. Mandibular plate and gula at least partially light brown, rarely brownish-yellow. At least ring at base of first antennal segment, or it in most part, or entirely dark brown or blackish; if first segment partly dark coloured then its rest part light brown (Fig. 33 B–E). Second antennal segment dark brown, except pale base or long ring before middle of length or pale entirely except apex and extreme base. Other antennal segments dark brown, third segment rarely pale at base. Rostrum brown yellow, with dark apex and sometimes first segment, slightly protrudes beyond hind coxae.
Collar yellow (male paratype, male from Tanzania and female from Somalia) or black (male and female paratypes). Pale band on posterior margin of pronotum moderately or very thin, often without extensions at ends, sometimes interrupted in middle. Scutellum dark brown or blackish, its apex yellowish. Internal, posterior part of corium, strip along its external margin and small spot in its apical external corner darker then rest part of corium, or it almost entirely dark brown except narrow strip along external margin, anterior corner and small strip along apical margin. Examined male paratype with almost uniformly yellowish brown corium. Cuneus dark red, except for yellowish extreme apex and narrow strip in external part of base. External part of cuneus appreciably darker then inner one. Sometimes cuneus brown (examined specimen from Tanzania). Thorax ventrally brown-yellow with light brown spots to dark brown. Evaporatorium whitish-yellow. Legs often entirely brown-yellow, femora with small brown spots or coxae and femora partially or completely brown. Tibia rarely with dark extreme base. Veins of membrane yellow, often with reddish patches.
Venter of abdomen dull yellow or light brown.
Right paramere (Fig. 35 A, B, E, F). Hypophysis appreciably longer and wider from lateral view than in two previous species, with widely rounded apex. Anterior wall of paramere body without tubercle under base of hypophysis.
Left paramere (Fig. 35 C, D, G, H) as long as right one. Hypophysis appreciably shorter than in previous species, with convex superior margin, straight before extreme apex, and with inferior margin straight on all length. Carina on internal (right) surface of hypophysis low (on posterior view), with dense, rather long setae.
Vesica (Fig. 36 B; 37 A–C). Anterior branch of anterior right lobe short, swollen anteriorly and widely rounded; right bladder absent, inferior one more convex than in previous two species. Inferior branch of anterior left lobe shorter than in D. longirostre, directed posteriad. Posterior left lobe without basal tubercle, with sclerotised triangular area on anterior wall. Apex of posterior right lobe T-shaped. Its right branch very long, directed to right, slightly curved posteriad and upwards. Left branch short, conical, directed to left and slightly downwards, its apex touches wall of vesica. Superior margin of posterior branch of spicule smoothly curved in apical part from posterior view in wet preparations (Fig. 36 H).
Gynatrium (Fig. 38 C). Notch on ventral margin of interramal sclerites of paratype deep, trapezoidal. In specimen from Somalia (described as Polymerus xerophilus) it rather shallow, arcuate. Areas of interramal sclerite on each side of medial process weakly sclerotised. Small longitudinal sclerite located near middle of dorsal margin of interramal sclerites merged with it, extended dorsally as tapering sclerotised band and reaching dorsal margin of gynatrial posterior wall.
Distribution. Uganda, new records for Tanzania and Somalia.
Taxonomic notes. Type series of Polymerus xerophilus Linnavuori, 1975 originally consisted of two females and a male. Later Linnavuori (1977) excluded the male belonging to D. longiristre from the type series and refined diagnosis of P. xerophilus. According to him this species as opposed to D. longiristre "is darker (cuneus brown, under surface and legs without red pigment, hind femora with abundant fuscous mottling), has much smaller eyes (ocular index 2.0–2.17) and only faintly marginate vertex, the body is shorter and broader and the legs are shorter and thicker (hind tibia only 1.4x as long as basal width of pronotum) ". According Linnavuori’s key P. xerophilus differs from D. ornatifrons by greater body size (4.0–4.2 vs. 3.7–4.1), pale first antennal segment (vs. brown to black), cuneus not distinctly red (vs. largely red or dark red), pale membranal veins (vs. veins red) and ocular index (2.0–2.17 vs.1.75 in female). I have studied the holotype of P. xerophilus, female (the paratype of this species is absent in the collection of R. Linnavuori, in NMWC and AMNH, which store most of his material) and found no significant characters distinguishing P. xerophilus from D. ornatifrons. Actually the female (paratype) of the latter species is greater than the holotype of P. xerophilus. A size and form of dark spot on the first antennal segment varies in all specimens of D. ornatifrons studied by me. The first antennal segment of P. xerophilus has dark base and the external wall in its basal half that lies in the limits of variability of D. ornatifrons (Fig. 33 B–E). Colouration of cuneus in the holotype of P. xerophilus is virtually indistinguishable from that of the two paratypes of D. ornatifrons (Fig. 42 D–F). A size of red patches on the membrane veins in the studied paratypes varies greatly from large in the males to very small in the female. A specimen from Tanzania is not different from the paratypes of D. ornatifrons in the structure of the terminalia and has membranal veins without red patches as well as the type of P. xerophilus. Ocular index (synthlipsis / width of eye) in the female types of D. ornatifrons and P. xerophilus is 1.83 and 2.00 respectively. A size of eyes in mirids correlates with a length of the hemelytra as it is generally known. This regularity can be seen also in this case: the membrane of D. ornatifrons is 5.59 times as long as body and is 6.21 times as long as body in P. xerophilus. By these reasons I consider the last name as a junior synonym of D. ornatifrons.
description: Published as part of Gapon, D. A., 2014, Revision of the genus Polymerus (Heteroptera: Miridae) in the Eastern Hemisphere. Part 1: Subgenera Polymerus, Pachycentrum subgen. nov. and new genus Dichelocentrum gen. nov., pp. 1-87 in Zootaxa 3787 (1) on pages 79-80, DOI: 10.11646/zootaxa.3787.1, http://zenodo.org/record/5079572