Birketsmithiola kruegeri sp. n.

(Figs 5–7, 21, 22, 30)

Paratypes: D. R . Congo: 1 female, [ Tanganyika Province] 17. 22. Marungu Plateau, W. side., S.W. Tanganyika, 7000 ft., Feb. 1922., T . A. Barns. / Joicey Bequest. Brit.Mus. 1934-120. / 004659 / QR-code label with unique number: NHMUK 014173033 / Arctiidae BMNH (E) slide No. 5696 (NHMUK) ; UGANDA: 1 male, at light, Feb. 21. 1916. Kigezi, c.6000, far SW corner of Uganda, 29°45′E. 1°15′S. G.D. Hale Carpenter, M.D. / at light, Kigezi, 21.2.16, gen. prep. No.: AV6807 (OUMNH) .

Diagnosis. The forewing length is 17.0 mm in males and 16.5 mm in female. The new species is externally reminiscent of B. sanguicosta but distinguished by the smaller size. The male genital capsule of B. kruegeri sp. n. differs from B. sanguicosta in the longer dorsal processes of the juxta which are almost equal in length to the ventral one. Additionally, the sacculus of the new species is somewhat broader than in the congener and its distal process is more dilated apically. The phallus of B. kruegeri sp. n. is somewhat dilated distally whereas it is of uniform width in B. sanguicosta . The vesica of the new species is markedly broader than in B. sanguicosta, lacks the subbasal diverticulum but bears one or two small cornuti ventrally (whereas in B. sanguicosta, only a distal cornutus is present). Since the females of the similar B. sanguicosta and B. kingstoni sp. n. are unknown, the copulatory organ of B. kruegeri sp. n. is compared to B. transvaalensis, from which the new species differs in the markedly broader and more heavily sclerotised posterior section of the corpus bursae, the broader medial constricted section of the corpus bursae, and the shorter and distally narrower appendix bursae. Compared to the species of the B. nyassana species group, the female of the new species has an orange costal strip on the forewing, and the markedly broader and more heavily sclerotised posterior section of the corpus bursae in the female genitalia.

Distribution. The species is known from eastern Democratic Republic of the Congo (Tanganyika Province) and south-western Uganda (Fig. 34).

Etymology. The new species is dedicated to the memory of the late Dr Martin Krüger (1963–2019), an outstanding expert in African Geometridae and Lithosiina taxonomy and author of the generic classification of Afrotropical Lithosiini (Krüger 2015) . The name is a noun in the genitive case.