Ectropina spirostachydis Triberti & Lopez-Vaamonde, 2024

Triberti, Paolo, Staude, Hermann, Sharp, Ian & Lopez-Vaamonde, Carlos, 2024, Exploring the diversity of Gracillariidae (Lepidoptera) in South Africa: host plants, distribution, and DNA barcoding analysis, with the description of nine new species, Zootaxa 5529 (1), pp. 1-51 : 8-9

7. Ectropina spirostachydis Triberti & Lopez-Vaamonde sp. nov.

( Figs 5 , 35–37 , 64 )

Holotype: ♂, South Africa, Limpopo, Hoedspruit, Casketts farm , mn 21/i/2015, pup 24/i/2015, em 01/ii/2015, Spirostachys africana , A. & I. Sharp leg. (rearing: M1027), CLV7574 , slide TRB4449♂.

Etymology. The species is named after the host plant Spirostachys , with its generic name declined in the genitive case.

Diagnosis. The forewing pattern of the new species is characterized by thin transversal yellow-whitish fasciae, which is similar to other members of this genus. However, there are certain distinguishing features that set this species apart from the related E. citricula , of which the male is not known. In E. citricula , the basal and median fasciae are nearly parallel, slightly arched, and relatively wide, extending to both the costa and dorsum. The apical fascia is reduced to a short, broad and irregular patch. In contrast, in E. spirostachydis the apical fascia is very long and slender, the median fascia is strongly arched and interrupted in the middle, and the basal fascia is straight, thin, and does not reach the dorsum. Additionally, there are two small and indistinct yellowish spots located basally with respect to the first fascia. Furthermore, in terms of male genitalia, the distinctive structure of the costo-apical process of the valva distinguishes this species from its relatives.

Description of adult ( Fig. 5 ). Forewing length 4 mm. Unfortunately, the holotype, which is the only specimen studied, is missing the head and legs. However, the forewing pattern, male genitalia and biology are available and sufficient to describe the species with certainty. Thorax. Wings. Ground colour is purplish fuscous irrorated with dark fuscous speckles. There are three narrow whitish yellow transverse fasciae at the base, preceded by two small irregular spots of the same colour. The first fascia is placed at the basal 1/5 of the wing, linear, sloping outwards but not touching the dorsum. The second fascia is strongly arched externally and interrupted near the costa by brownish scales. The third fascia is long and thin, directed towards the tornus, extending from the costa to touch the dorsum. Along the dorsum, there are tufts of darkish scales in the interspace of the fasciae. The apex of the wing has a white ciliary streak and an indistinct subapical black dot bordered almost completely by pale scales. Abdomen. Segments VII and VIII are weakly membranous, with two pairs of coremata that are more or less the same in length and thickness. Tergum VIII is reduced into a fan-shaped sclerite with a narrow median ridge ( Fig. 36 ). Male Genitalia ( Fig. 35 ). The tegumen is short, ventral margins with several strong setae, apical margin notched, the two halves slightly rounded apically forming large projections which could be understood as falces (sensu Vari, 1961; Kumata, 1988b).The valva is rather short and broad, with three robust teeth on the costo-apical corner. The vinculum is large, slightly shorter than the valva, and the saccus is very short. The phallus is tubular ( Fig. 37 ), doubly sinuate, about as long as the vinculum. It slightly narrows in the first 2/3 and then has parallel edges, thin and pointed apically. The distinction between the phallobase and the aedeagus is unclear. The anellus is short and membranous, with a lateral pair of microsetosae lobes and a ventral sclerite, probably the juxta. The manica covers about 2/3 of the phallus and the bulbus ejaculatorius was not observed. Female genitalia. Unknown.

Biology. Larvae feed on Spirostachys africana ( Euphorbiaceae ) ( Fig. 64 ). The last instars of these larvae are easily identifiable by the small red spots that appear along their bodies. Based on the current knowledge of this genus it is believed that the two Indian species, E. acidula ( Meyrick, 1911b) and E. raychaudhurii Kumata, 1979 feed on Euphorbiaceae (specifically the genus Phyllanthus ), while the South African E. sclerochitoni feeds on Acanthaceae .

Distribution. South Africa (Limpopo).

DNA barcodes. The specimen’s DNA amplification failed (SOURE 018-19).

Figures

FIGURES 1−6. Adults of South African Gracillariidae. 1, Caloptilia sp., Limpopo, Lekgalameetse N. R., A. & I. Sharp leg. 2, Caloptilia rhusina, Western Cape, Robberg Nature Reserve, S. Mecenero leg. 3, Macarostola noellineae, Limpopo, Hoedspruit, A. & I. Sharp leg. 4, Caloptilia cataractias, Limpopo, Hoedspruit, leg. A. & I. Sharp. 5, Ectropina spirostachydis sp. nov., Limpopo, Hoedspruit, A. & I. Sharp leg. 6, Graphiocephala barbitias, Gauteng, Tshwane, A. Sharp leg.

FIGURES 35–39. Male genitalia of South African Gracillariidae. 35-37, Ectropina spirostachydis sp. nov., holotype: 35, ventral view (240 μm); 36, tergum VIII detail (140 μm); 37, phallus (120 μm). 38, Cryptolectica capnodecta: ventral view (240 μm). 39, Conopobathra gravissima: valva detail (280 μm).

FIGURES 61−66. Immature stages of South African Gracillariidae. 61, Caloptilia sp., larva on Cryptocarya transvaalensis (Lauraceae), Limpopo, Lekgalameetse N. R., A. & I. Sharp leg. 62, C. cataractias, larva on Rhynchosia minima (Fabaceae), Limpopo, Hoedspruit, A. & I. Sharp leg. 63, Macarostola noellineae, larva on Syzygium cordatum (Myrtaceae), Limpopo, Hoedspruit, A. & I. Sharp leg. 64, Ectropina spirostachydis sp. nov., larva on Spirostachys africana (Euphorbiaceae), Limpopo, Hoedspruit, A. & I. Sharp leg. 65, Cuphodes melanostola, mine on Euclea divinorum (Ebenaceae), Limpopo, Hoedspruit, A. & I. Sharp leg. 66, Conopomorphina ochnivora, Gauteng, Magaliesburg, on Ochna pretoriensis, (Ochnaceae), H. Staude leg.