Chrysacanthia iwo, Winterton, Shaun L. & Brooks, Stephen J., 2015

Winterton, Shaun L. & Brooks, Stephen J., 2015, Review of the green lacewing genus Chrysacanthia Lacroix with a new species from Nigeria (Neuroptera, Chrysopidae), ZooKeys 517, pp. 71-81 : 76-79

Taxon classification Animalia Neuroptera Chrysopidae

Chrysacanthia iwo sp. n. Figures 2, 3, 4

Type material.

Holotype male, NIGERIA: Osun State: Iwo, 2.iii.1973, cashew leaf, pres. By Comm. Inst. Ent. B.M. 1977-1, BMNH(E) 1201743 (Natural History Museum, London). Type condition: poor, damaged: antennae missing, abdomen and genitalia dissected.

Diagnosis.

Head and thorax dark with pale linear markings; hind wing with single mark along posterior margin at pseudomedial crossveins 2-3; femora unmarked.

Description.

Male: Wing length (forewing: 15.0 mm; hindwing: 13.0 mm). Overall colouration very dark brown to black, with cream coloured abdomen with black polished tergites posteriorly and dark markings in wings. Head (Fig. 3). Dark brown with white markings; vertex with pale crescent marking around base of an tenna, behind eye and posteriorly along vertex ridge; labrum and gena pale, clypeus with pale suffusion laterally with white band across lower margin; antennal scape dark brown, flagellum colour unknown (missing in specimen); palpi light brown-tan, unmarked. Thorax (Fig. 3). Prothorax dark brown dorsally, cream ventrally, medium length pale setae sparsely distributed; pronotum with two longitudinal mid-dorsal stripes, curving outwards and approximating posterolateral corner, stripes overlain with short dense silver pubescence; mesonotum and metanotum dark brown with pale markings, overlain with pubescence, denser and silvery posteriorly and medially, admixed with sparse pale setae; pleuron dark brown on upper portion, cream on lower portion; legs pale with white setae, tibiae with a narrow dark brown mark at midpoint dorsally; claws pale basally, brownish apically on all legs, claw dilated basally; wings hyaline with extensive makings, especially in forewing; forewing with seven inner gradate crossveins, one set doubled apically, meeting Psm posteriorly; eight outer gradate crossveins, one set doubled apically; two crossveins between Cu1 and Cu2, 1st posterior marginal crossvein joining wing margin proximal to Cu2; hind wing with five inner gradate crossveins, seven outer gradate crossveins; wing hyaline with markings as per Figure 2A, forewing more extensively marked than hindwing; venation mostly white, brown when crossing infuscate areas and at junctions of crossveins with major veins; basal subcostal crossvein dark; pterostigma very dark in both wings; single mark along posterior margin of hind wing and at apex of fore wing. Abdomen. Predominantly white; tergites 4-7 polished black-brown; sternites 7-8+9 brown; sternite 7 with conical posteromedial process; tergite 8 and 9+ectoproct pale. Male terminalia (Fig. 4): Trichobothria ca. 35; paramere elongate, upturned apically, not extending beyond apex of abdomen; gonarcus relatively short, broad, with elongate gonocornua; arcessus broad with lateral hook-like process; gonosaccus weakly developed with paired lateral gonosetae.

Female: unknown.

Comments.

This Afrotropical species of Chrysacanthia is easily differentiated from other species in the genus by the head and thoracic markings (i.e., dark brown with pale stripes and arch-like markings), unmarked femora, relatively short paramere, single spot on the posterior margin of the hind wing, and well developed mark at the base of the inner gradate series of the forewing. Chrysacanthia iwo sp. n. is known only from the holotype male collected on cashew in Iwo, Nigeria.

Members of this genus are very distinctive based on wing venation and markings on the head and thorax. The Malagasy Chrysacanthia varicella was excellently figured by Fraser (1951) (reproduced here; Fig. 2B). This species is very similar to C. iwo sp. n., but can be differentiated by the presence of two wing spots along the posterior margin of the hind wing; in Chrysacanthia iwo sp. n. only one spot is present. The Afrotropical species are typified by pale markings on a dark head and thorax, while in the Oriental species are more uniform dark. Chrysacanthia esbeniana (India) is distinguished from the other Oriental species, Chrysacanthia hainana (China, Thailand), by the presence of a dark spot at the base of the inner gradate series in the forewing (Figs 1, 2C).

Etymology.

This new species is named after the type locality, the township of Iwo, SW Nigeria.