Orthotrichia mlamboi, Wells & De Moor, 2020

Wells, Alice & De Moor, Ferdinand C., 2020, Hydroptilidae (Trichoptera) of Angola, a new genus, seven new species, and five new records, Zootaxa 4868 (4), pp. 495-514 : 507

Orthotrichia mlamboi sp. nov.

( Figs 37–39 )

Material examined. Holotype male, [CAW 855M, slide], ANGOLA, Huila Province, Cubango River, Site 21 — downstream of rapids at ruins of hydropower plant, at light, -14.3384, 16.29331, 15/v/2017, I.S. Ferreira & M. Mlambo.

Diagnosis. A member of the Or. angustella -group, this species resembles very closely Or. straeleni Jacquemart 1956 from Lake Kivu, (now) DRC, but differs in several features of male genitalia, particularly the length of the inferior appendages about 2X longer, the inferior appendages in lateral view more slender and the proximal spine on tergite X more slender.

Description. Male. Length of each forewing 1.8 mm (n = 1); short pocket of jet-black scales proximally on costal margin ( Fig. 44 ). Antennae 29 flagellomeres, rectangular in profile, surface bearing close-packed sensilla placodea.

Abdominal sternite VIII with well-developed medial lobe bearing stoutish setae. Genitalia: segment IX with lateral margins produced distally to form unequal mesally curved processes, left longer than right, each bearing long stout seta subapically, tergite X (‘dorsal plate’) membranous, stout in dorsal view, with 2 sharp opposing spurs at about 2/3 length curved toward right; inferior appendages unequal, discrete basally, left constricted at distal 2/3, apical region forming slender twisted process, bilobed processes slender, closely associated, ventral apodeme (mesoventral apotome at base of inferior appendages) short narrow; phallus long, slender, with spiral titillator at about half length.

Etymology. The species is named mlamboi after Musa Mlambo a scientist and colleague at the Albany Museum.

Distribution. Known only from Angola.

Remarks. The new species of Orthotrichia is one of a set of closely similar African species all with strongly asymmetric male genitalia.AW examined types where available on loan, including the very large collection of slides of Orthotrichia straeleni from the RBINS (58 slides in total), including the holotype (dissected and in parts on 4 slides) and several paratypes. The slides are very poor, a number of the specimens squashed beyond recognition.All the ‘adequate’ preparations of males show features consistent with Jacquemart’s (1956) description and are distinct from Or. mlamboi . AW also examined the holotypes of Or. petiti Jacquemart 1962 (on loan from RBINS; from Zaire), and Orthotrichia nova Marlier 1978 (on loan from RMCA; from Angola), again finding all distinct from Or. mlamboi . The type male of Or. verbekei Jacquemart 1957 (on loan from RBINS), from (now) Democratic Republic of Congo, also differs.

Figures

FIGURES 37–44. Orthotrichia spp.: 37–39, Orthotrichia mlamboi sp. nov, [CAW 855M], male genitalia: 37, ventral; 38, dorsal; 39, left lateral. 40–44, Orthotrichia ferreirae sp. nov., male [CAW 757AW]: 40, phallus, ventral; 41, ventral; 42, dorsal; 43, left lateral, slightly skewed. 44, forewing costal scales.Abbreviations: IX, X = abdominal segment IX and tergite X; b. pr. = bilobed process; inf. app. = inferior appendage (paired); lt. lb. IX = lateral lobe of segment IX (paired); me. ap. = mesoventral apotome at base of inferior appendages and bilobed process; me. lb. = medial lobe on segment VIII; pr. = paramere; ph. = phallus; sp. IX = spine on tergite IX; tl. = titillator.