Metarctia (Metarctia) kiwengwa, Spitsyn, 2024

Spitsyn, Vitaly M., 2024, A new species of the genus Metarctia Walker, 1855 from Zanzibar Island (Erebidae: Arctiinae: Syntomini), Ecologica Montenegrina 75, pp. 85-88 : 86-88

Metarctia (Metarctia) kiwengwa sp. nov.

https://zoobank.org/ urn:lsid:zoobank.org:act:5188C321-31A6-496E-86DF-2E6BE11DD2F9

Fig 1 .

Type material. Holotype: ♂, RMBH Sph 1054; TANZANIA: Zanzibar Island, Kiwengwa Forest , dry monsoon forest, 5°59'S, 39°21'E, 24.03- 12.04.2021, E. Spitsyna & V. Spitsyn leg.

Paratypes: 5♂, 2♀, RMBH Sph 1055- Sph 1061; TANZANIA: Zanzibar Island, Kiwengwa Forest, dry monsoon forest, 5°59'S, 39°21'E, 24.03- 12.04.2021, E. Spitsyna & V. Spitsyn leg. ; 13♂, 13♀, RMBH Sph 1229- Sph 1254; TANZANIA: Zanzibar Island, Kiwengwa Forest, dry monsoon forest, 5°59'S, 39°21'E, E. Spitsyna & V. Spitsyn leg. (the specimens were obtained from larvae which were grown under laboratory conditions).

Diagnosis. The new species differs from the most species of the genus Metarctia in the large and broad uncus, the almost square valva with the long apical process (approximately equal to length of valva). Additionally, the new species can be distinguished from those species of the genus, the male genitalia of which are unknown, by light brown forewings with the darkened anal margin, black spot at the end of the abdomen on the dorsal side. Finally, the new species is distinguished from those species, for which only the female is known, in the dark brown forewing colouration with a bright light basal area.

Description. Male: Wingspan 28-33 mm, forewing length 14-17 mm. Eye black. Antenna brown. Head orange-brown. Frons grey-brown. Labial palpus (its length approximately two of eye diameter) grey-brown on outer lateral side, orange-brown on inner lateral side. Thorax, patagium, and tegula orange-brown. Legs orange-brown, tibia and tarsus grey-brown. Upperside of forewing light brown with black-grey point at apex of central cell. Underside of forewing light orange-brown. Upperside of hindwing light orange-brown. Underside of hindwing light orange-brown. Abdomen light orange-brown with black spot at apex. Male genitalia: Tegumen broad, strongly sclerotized. Uncus very broad. Valva square with long apical process. Vinculum elongated. Aedeagus long, straight with broad base. Female: Wingspan 39-40 mm, forewing length 19-20 mm. Eye black. Antenna black-brown. Head orange-brown. Black-brown spot near eyes. Labial palpus (its length approximately two of eye diameter) grey-brown on outer lateral side, orange-brown on inner lateral side. Thorax, patagium, and tegula orange-brown. Legs orange-brown, tibia and tarsus grey-black. Upperside of forewing brown, pink-orange basally. Underside of forewing from base to apex of central cell pink-orange, other part of wing brown. Upperside of hindwing pink-orange. Underside of hindwing pink-orange with brown veins and costal margin. Abdomen light orange-brown with black spot at apex dorsally, and black with light orange-brown spots ventrally. Female genitalia: Papilla analis broad. Apophysis posterioris of medium size, apophysis anterioris very short. Corpus bursae rounded with large signum. Last instar larva: Head capsule dark brown. Eyes black. Ground colour grey-brown. Legs brown. Each body segment has 10 verrucae with a lot of dark brown hairs. Spiracles oval black-grey. Pupa: Total length 17-19 mm; maximum width 7-8 mm; black-brown ( Fig. 1E ); antennae and legs well developed, protuberant; black abdominal spiracles slightly rising above cuticular surface. Pupal development takes 15 days.

Remark. The hairs of larva are toxic. It causes redness and itching of the skin by contact. And in cases with prolonged contact, it can cause joint swelling.

Larval host plants used in breeding experiments: Cucurbita spp. ( Cucurbitaceae ), Ipomoea batatas ( Convolvulaceae ), Salix spp. ( Salicaceae ).

Etymology. The new species is named after Kiwengwa Forest, where it is distributed.

Distribution. The new species is known only from the type locality.

Conservation. The species is probably on the verge of extinction because of Kiwengwa Forest from which the new species was collected is actively being cut down by local people.

Acknowledgements

This study was supported by the Russian Ministry of Science and Higher Education (project No. FUUW-2023-0001).

References

Przybyłowicz, Ł. (2009) Thyretini of Africa. An Illustrated Catalogue of the Thyretini (Lepidoptera: Arctiidae: Syntominae) of the Afrotropical Region. Series: Entomonograph, Volume 16, Apollo Books, Stenstrup, 170 pp.

Ochse, M. (2017) Arctiinae der Subtribus Thyretina in der westafrikanischen Regenwaldregion (Erebidae). Nachr. entomol. Ver. Apollo, N.F., 38 (1), 1–22.

Fiebig, R., László, G. M., Volynkin, A. V. & Taberer, T. R. (2023) Integrative taxonomic revision of the Metarctia Walker, 1855 subgenus Hebena Walker, 1856 , with descriptions of six new species and one new subspecies ( Lepidoptera : Erebidae : Arctiinae: Syntomini). Zootaxa, 5339 (4), 301–354.

Figures

Figure 1. Metarctia kiwengwa sp. nov. from Kiwengwa Forest, Zanzibar Island, Tanzania: A) Male, holotype; B) Female, paratype; C) Male genitalia and aedeagus; D) Female genitalia; E) Pupa (dorsal, lateral, and ventral view, respectively); F-G) Larva.