Orthotrichia ferreirae, 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 : 508

Orthotrichia ferreirae sp. nov.

( Figs 40–44 )

Material examined. Holotype male, [CAW 757 AW, slide], ANGOLA, Moxico Province, Cuembo River, Site 6— Cuembo campsite bridge, Light trap, -13.5265, 19.27971, WGS84, 01/11/2016, I.S. Ferreira.

Paratypes, ANGOLA: 9 males [CAW 757F], collected with holotype , same data ; 3 males (one on slide) [CAW 891AZ], Moxico Province, Lungue Bungo River, Collecting event 3— downstream of road-bridge Light trap, -12.57898 18.67073, 21/iv/2018, H.M. Barber-James & F.C. de Moor ; 1 male [CAW 892U], Moxico Province, Lungue Bungo River, Collecting event 3—upstream of road-bridge, Light trap, -12.58670, 18.66928, 21/iv/2018, H.M. Barber-James & F.C. de Moor .

Diagnosis. Males are distinguished from other central African Orthotrichia species by strongly asymmetric male inferior appendages and the sclerotised inwardly turned L-shaped spine on tergite IX and the L-shaped inwardly turned paramere crossing the spine.

Description. Male. Length of each forewing 1.7–1.8 mm (n = 10); short pocket of jet-black scales proximally on costal margin. Antennae (all damaged) with flagellomeres rectangular in profile, bearing abundant sensilla placodea.

Abdominal sternite VII bearing small sharp spur medially on distal margin; sternite VIII bearing medial lobe of stoutish setae. Genitalia: segment IX bearing short row of strong setae mid ventrally towards apex, dorsally equipped with one sclerotised L-shaped spine, lateral margins produced distally to form unequal processes, in dorsal view right side longer than left, and bearing 2 stout setae towards apex, left more slender and bearing single seta apically; tergite X (‘dorsal plate’) stout with irregular excavation at apex; inferior appendages unequal, fused basally, right appendage curved, strongly tapered towards spinelike apex, left appendage stout, irregular in shape, with curved spine subapicomesally, membranous lobes of bilobed processes slender, closely associated, mesoventral apodeme reaching to proximal margin of segment VIII; phallus elongate, slender, with spiral titillator at about half length; paramere slender, L-shaped.

Etymology. Named for Ina S. Ferreira who collected much of the material upon which this study is based.

Distribution. From sites along the Cuembo and Lungue Bungo Rivers in Moxico Province.

Remarks. Specimens were all collected ‘along marshy riverbanks with swift flowing river containing trailing and marginal aquatic vegetation’ as in Figure 48 .

The male genitalic structures of this species are extremely difficult to understand: their homologies are almost impossible to interpret and even determination of their spatial relationships is difficult, so much being dependent upon the extent to which the ninth segment is retracted within the eighth, and the aspect in which they are viewed.

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.

FIGURES 48, 49. Collection sites representative of those surveyed: 48, Lungue Bungo River flowing through Kalahari sand substrate with marginal, trailing aquatic and some woody vegetation [Photo F.C. de Moor]; 49, rapids on Cubango River. [Photo I.S. Ferreira].