Hylaeus (Deranchylaeus) xanthostoma
Creators: name: Dathe, Holger H.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Colletidae
Hylaeus
Hylaeus xanthostoma

description: Hylaeus (Deranchylaeus) xanthostoma (Alfken, 1914)
Figures 15, 146–149
Prosopis xanthostoma Alfken, 1914: 196–197. 7 ♀ 1 ♂, Belgisch Kongo [DR Congo]: Bukama, Mufunga; Stanleyville (♂). Syntypes MNHU Berlin, ♀ labeled "Musée du Congo, Bukama, 10 VII 1911 Dr. Bequaert " designated here as lectotypus, a second ♀ as paralectotypus. Snelling labeled the single ♂ "Stanleyville 20-X-10" as lectotypus (not published) which is expressively excluded here; this specimen is a Nothylaeus, Hylaeus (Nothylaeus) ameliae Ckll.
Prosopis xanthostoma Alfken: Friese 1916: 417, 426–428; Cockerell 1942: 3, 15; Medler 1980: 480.
Hylaeus (Deranchylaeus) xanthostoma (Alfken): Bridwell 1919: 138–139, 147; Snelling 1985: 8.
Hylaeus xanthostoma (Alfken): Eardley & Urban 2010: 37.
Hylaeus kasindensis Cockerell, 1936e: 2, 4, 8. 2 ♂, Belgian Congo [DR Congo]: Kasindi to Beni 29”30’E 0°30’N. Typus ♂ AMNH New York, ac. 34187, genital parts dissected, sternum 8 missing.— Syn. n.— Eardley & Urban 2010: 31.
Hylaeus (Deranchylaeus) kasindensis Cockerell: Snelling 1985: 8.
Diagnosis
This is one of the smallest species of the subgenus. The female is unique in the subgenus due to its orange lower face. The terminal area of the propodeum has a circular sharp edged carina. The punctation is seemingly variable.
Characteristic features
Male. TL 3.6–4.7 (4.23) mm, WL 2.3–3.0 (2.84) mm.
Head. Proportions HL:HW 0.99, UFW:LFW 1.73, outline rounded trapezoid. Scapi short conical, as wide as flagella, SL:SW 1.5, black with yellow triangular spot above; flagella long, yellow, above dark; mask yellow, complete, side patches exceed scapi bases towards orbits, mouth parts included; foveae faciales short. Clypeus CL:CW 1.55, silky shining, punctation moderately shallow scattered; frons and vertex with punctures arranged in wrinkle stripes. Labrum and mandibles yellow.
Mesosoma. Pilosity sparse. Bright colored: pronotum sides with small yellow stripes, calli and tegulae spotted. Pronotum narrow expanded forward, anterior margin sharp to corners, posterolateral angles acute. Mesonotum and scutellum shagreen, shiny, punctation strong, close; mesopleurae with coarse, close punctation, punctures shallow, each with a short bristle in center. Legs black, white are: tibiae basally and apically, foretibiae in front, tarsi; wings hyaline, venation light brown. Propodeum edged, shiny, medial area with irregular longitudinal ridges, delimited at end by carina, terminal area sharp surrounding edge.
Metasoma slender spindle-shaped, black. T1 shagreen, silk shiny, punctation minute, scattered, on following terga with punctation hardly recognizable; T1 with sparse lateral fringes. Terminalia (Fig. 15) similar H. promontorii (Fig. 12).
Female. TL 4.2–5.3 (4.75) mm, WL 2.9–3.7 (3.29) mm.
Head. Proportions HL:HW 1.00, UFW:LFW 1.47, outline prolonged trapezoid. Face black, lower parts—clypeus, wings, labrum and mandibles—in varying extent yellow orange, orange coloration may involve also scapi; face sometimes even with white comma spots at orbits; foveae faciales long. Clypeus CL:CW 1.05, punctation as well as face sides strong but shallow. Frons and vertex with moderate, dense punctation.
Mesosoma only with spot on tegulae, otherwise black. Pronotum slightly expanded forward, anterior margin sharp-edged, dorsolateral angles acute. Mesonotum and scutellum shagreen, slightly shining, punctation strong, close; mesopleurae irregularly shallow punctate, with moderate to strong, close punctation. Legs black, foretibiae in front yellow striped; wings hyaline, venation brown. Propodeum edged, structure, in principle, as in male; terminal area sharply edged around.
Metasoma compact spindle-shaped, black. T1 shagreen, silk shiny, punctation minute, scattered, following terga without obvious punctures; T1 with narrow white lateral fringes.
Distribution
Democratic Republic of the Congo, Namibia, Nigeria, South Africa (Eardley & Urban 2010); Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Ethiopia, Kenya, Malawi, Mozambique, Senegal, Tanzania, Zimbabwe.
Specimens examined: 69 ♂, 139 ♀ coll. AMNH, MNHU, NHML, OLBL, RBINS, SAMC, SANC.
BENIN. SE, Save 15 km SE.
BOTSWANA. N, Maun, Island Sateri¸ L. Ngami, Sehithwa 19 km NE.
BURKINA FASO. Bobo-Dioulasso; Dingasso nr. Bobo.
BURUNDI. Ruvubu National Park, Ruvubu River, 02.59.20S 30.28.12E, 1401 m.
CAMEROON. Adamaoua: Beka nr Ngaoundere, 07.17N 13.19E; de Banyo à Tibati, 06.37N 12.07E; Louga W Ngaoundere, 07.05N 13.12E; Massif du Mbam, Jakiri, 06.01N 10.33E; Mayo-Darlé, 06.28N 11.33E; Tékel, 06.47N 13.10E. Cameroun W, Wum, 06.24N 10.03E.
CENTRAL AFRICAN REPUBLIC. Bambari 20 km NW; Bangui 85 km NW, 04.46N 18.04E, 380 m; Bangui 90 km NNE, 05.03N 18.47E, 380 m; Bouar ca. 60 km W, 05.45N 15.13E, 660 m; Kaga Bandoro 40 km N, 06.41N 19.07E; Sibut 45 km N, 06.06N 19.08E, 530 m; Sibut 80 km W, 05.41N 18.17E; Sibut 95 km W, 05.12N 18.25E.
DEMOCRATIC REPUBLIC OF THE CONGO: Bukama, Mufunga; Kasindi to Beni 29.30E 00.30N.
ETHIOPIA. Awash National Park, 08.55N 40.02E; Bale, Sof'Omar, 06.13'06N 39.46'18E; Mechara W Hararge, 08.36N 40.19E.
KENYA. Laikipia, Mpala Res. Centre, 001748N 0365382E; Malindi 15 km S, 03.18S 40.00E; Mwingi E, W of Nguni; Voi env., Tsavo.
MALAWI. Liongwe 80 km E.
MOZAMBIQUE. Save 15 km SE, 21.13S 34.40E, 65 m; Guro 15 km S, 17.33S 33.16E, 800 m.
NAMIBIA. Between Omaruru and Wilhelmstal, 21.31S 16.03E; Kaoko Otavi.
NIGERIA. Gashaga Gumfi National Park, 25 km SW Serti env., 07.20N 11.13E, 400 m.
SOUTH AFRICA. Eastern Cape: Fort Beaufort; Grahamstown, Howlson’s Poort; Jansenville 25 km N, 32.49S 24.44E, 600 m. — KwaZulu-Natal: Maputaland, eManguzi SW.— Limpopo: Malta Forest nr The Downs, 24.10S 30.14E; Ryfontein Farm 15 km SE Tzaneen, 23.54S 29.45E.— Mpumalanga: Skukuza, 24.59.32S 31.3504E.
SENEGAL, Thiès; Tiougoune.
TANZANIA. Mikomazi Game Reserve, Ibaya Camp, 03.5791S 37.4809E.
ZIMBABWE. Centr., Ngezi Recreational Park Kwekwe; Chimanimani National Park; East, Chipinge 40 km S, Mt. Selinda; Rezende Mine, Penhalonga, 18.53S 32.43E.
Flower visit
On flowers of Acacia nilotica, Acacia tortilis (Baldock, label record); Aloe berhana, Borreria verticillata, Harungana madagascariensis, Pterolobium stellatum, Vernonia auriculifera, Ziziphus mauritiana (Pauly, label record).
Remarks
The male is described here for the first time. According to the male terminalia, the species belongs to the curvicarinatus-group. We found some variation. Other than described above, there are males with black supraclypeal area and 4 bristles only on basal lobi of S7 and gonoforcipes narrower.
The species is widespread in Africa and seems to vary greatly between populations, especially in surface sculpture and colour. The mesonotum and the mesopleurae can be punctate strong to coarse with different density. The color variations of the females range from limited yellow-orange staining of clypeus and mandibles to a predominantly bright face; as well as variations in the coloration of the legs from totally black to nearly fully yellow. Stable combinations of these features which would justify a taxonomic separation could not be found. Rather, it appears to be a geographical gradient, hence the western animals from Senegal, Burkina Faso, Benin and Cameroon, show a coarser and stronger mesosoma punctation, while eastern specimens from Ethiopia, Kenya, Tanzania, Mozambique and further south from Malawi, Mozambique, Botswana, Namibia and South Africa have finer surface structure. H. xanthostoma is one of the most common and the one with the broadest known distribution out of all the Deranchylaeus species treated here,
description: Published as part of Dathe, Holger H., 2014, Studies on the systematics and taxonomy of the genus Hylaeus F. (8) Revision of the Afrotropic subgenus Hylaeus (Deranchylaeus) Bridwell (Hymenoptera: Anthophila, Colletidae), pp. 1-84 in Zootaxa 3874 (1) on pages 74-76, DOI: 10.11646/zootaxa.3874.1.1, http://zenodo.org/record/4948240