Nemophora acaciae Agassiz & Kozlov

Agassiz, David J. L. & Kozlov, Mikhail V., 2015, Description of Nemophora acaciae sp. nov. (Lepidoptera: Adelidae) from Kenya, Zootaxa 4058 (2), pp. 287-292 : 288-291

Nemophora acaciae Agassiz & Kozlov sp. nov.

( Figs. 1–9 )

Material. Holotype ♂: Kenya, Rift Valley, Njoro, 2130 m (0°19'59"S, 36°58'13" E), ex flowers of Acacia lahai , larvae coll. 11.v.2014, moths emerged 1.vii.2014, D.J.L. Agassiz ( NMK). Paratypes: 3 ♂ 2 ♀, same label ( NMK); 2 ♂ 3♀, same label ( MZH); 1 ♂ 1♀, same label ( ZIN); 14 ♂ 7 ♀, same label, but moths emerged 2.–11.vii.2014 (NHM); 9 ♂ 4♀, Rift Valley, Lessos, 2160 m (0°12'3"N, 36°18'48"E), ex flowers of Acacia lahai , larvae coll. 11.v.2014, moths emerged 30.vi.–4.vii.2014, D.J.L. Agassiz (NHM); 5 ♂ 5♀, Rift Valley, Nakuru, 2250 m (0°14'41"S, 36°06'4" E), ex flowers of Acacia seyal , larvae coll. 11.v.2014, moths emerged 27.vi.–11.vii.2014, D.J.L. Agassiz (NHM).

Etymology. Named after larval host plant, Acacia lahai .

Diagnosis. N. acaciae differs from all other Afrotropical species by dark brown forewing fascia with white medial stripe near the costal margin of forewing.

Description. Male ( Figs. 1 , 3). FWL 5.6–5.9 mm, width / length ratio 0.32–0.34. Vertex black; frons glossy silver, with a row of protracted black piliform scales below antennal sockets. PLB 0.5–0.6× vertical eye diameter, ventrolaterally covered by long raised black scales, internal side dorsally with sparse short white scales. Proboscis brown, base with bronze scales. Eyes enlarged; interocular index 1.0–1.1. Antenna 1.95–2.25× FWL, with simple inwardly directed pegs on the basal flagellomeres. Scape black; base of flagellum black, slightly flattened; colour gradually changing to bronze; in some specimens, apical part of flagellum silver-grey. Tegula and thorax dark bronze. Forewing ( Fig. 3) bronze basally to coppery bronze apically, with Y-shaped dark brown fascia that surrounds short white to creamy stripe separating its arms near the costa; internal margin of fascia reaches costa at 0.45× FWL; base of forewing with small, sometimes indistinct, brown spot. Fringe bronze. Hindwing basally translucent, apically light bronze; costal area grey; fringe light brown to grey. Legs from glossy golden to coppery bronze; hind tibia both ventrally and dorsally with long grey piliform scales. Epiphysis at 0.6, reaching apex of tibia. Abdomen black dorsally to bronze ventrally.

Female ( Fig. 2 ). FWL 5.0– 5.4 mm. Vertex glossy bronze; wide protracted scales extended frontally beyond the antennal sockets, covering basal half of scape. Antenna 1.05–1.15× FWL, base not thickened. PLB dorsally covered with appressed white scales; raised black piliform scales on the ventral side shorter and sparser than in male. Otherwise similar to male.

Male genitalia ( Figs. 4–8 ). Tegumen dome-shaped, with prominent medial ridge. Socii oval, equal to diameter of phallus. Vinculum 2.8× length of valva, with straight lateral margins; proximal margin widely rounded; distal margin gently w-shaped. Apex of tegumen slightly extended beyond apex of valva. Ventral margin of valva with distinct lobe reaching 0.5× length of valva; dorsal margin nearly straight; apex, seen from ventral side, narrowly rounded. Valvae fused basally up to 0.4× total length; the medial suture clearly visible. Anellus 0.6× length of valva. Transtilla with long pointed medial process. Juxta 0.55× length of phallus, arrow head wide (width / length ratio 1.0), with widely rounded tip and short pointed lateral arms. Phallus 0.9× length of vinculum, almost straight, except for dorsally protruded base and ventrally protruded apex. Apical part of phallus wide, seen from ventral side, 2.5× width of the medial part of phallus. Base of phallus widely funnel-shaped.

Biology. Flowers were sampled from acacia trees alongside a road in non-cultivated areas of typical upland savanna country. The specimens were observed emerging from cases fixed on the sides of the box that contained flowers of Acacia seyal as well as A. lahai , or amongst plant remains. We presume that females oviposited into the flower buds, and the first-instar larva feed on the developing flower. Then the larva constructed a case; however, it remains unknown whether the older larvae normally feed with flowers and developing seeds or descends to the litter below the host plant, because larvae were not observed prior to pupation. Larval case is oval, flattened, dark brown ( Fig. 9 ).

Botanists have recently divided the genus Acacia into smaller genera. Those in Africa are either Senegalia or Vachellia ( Orchard & Maslin 2003) , but this is disputed by some and for the purpose of this paper Acacia sensu lato is used since it is well known and conveys meaning as the English name for these trees.

Distribution. So far the species has only been recorded from the Nakuru district of the Rift Valley Province of Kenya. However, the species may have a wider distribution, because one of its hosts, Acacia lahai , also occurs in Ethiopia, Uganda and Tanzania, whereas another host, A. seyal , is widespread throughout tropical Africa ( Dharani 2006).

Figures

FIGURE 1. Nemophora acaciae sp. nov., male, holotype.

FIGURE 2. Nemophora acaciae sp. nov., female, paratype.

FIGURE 9. Nemophora acaciae sp. nov., larval case with exuvia.

FIGURES 4 – 8. Nemophora acaciae sp. nov., male, holotype: (4) genital complex, ventral view (right valva not shown); (5) genital complex, lateral view; (6) juxta; (7) phallus, ventral view; (8) phallus, lateral view.