Dolgoma diktyo, Volynkin & Černý, 2021

Volynkin, Anton V. & Černý, Karel, 2021, Taxonomic review of the genus Dolgoma Moore (Lepidoptera: Erebidae: Arctiinae) from Thailand with descriptions of three new species, Zootaxa 5060 (3), pp. 417-428 : 419-420

Dolgoma diktyo sp. n.

( Figs 1, 2 , 17 , 26 )

Dolgma [sic] reticulata: Černý & Pinratana (2009) .

Type material. Holotype ( Figs 1 , 17 ): male, “N. Thailand Chiang Mai-prov., Fang distr. Doi Pa Hom Pok, 2050m 20°07’30’’N, 99°08’49’’E 21.IV.2006 leg. K. Cerný [recte: Černý]” / “Slide AV4732 ♂ A. Volynkin ” ( MWM / ZSM, ex CKC).

Paratypes: THAILAND: 2 males, 5 females, same data as for holotype ; 1 male, 1 female, same locality and collector as for holotype, 5–6. V. 2006 ; 4 females, Doi Inthanon, Angka Hocmoor [high mountain swamp], 2500m, 19°35’N, 98°29’E, 10.IV.[19]96, Malicky & Chantaramongkol [leg.], gen. prep. No.: AV4733 (prepared by Volynkin) (all in CKC) .

Diagnosis. The forewing length is 14 mm in males and 16 mm in females. The new species ( Figs 1, 2 ) is superficially similar to the Himalayan D. reticulata ( Figs 3, 4 ) but differs in the somewhat larger size (the forewing length of D. reticulata is 12.5–14 mm in males and 15–16 mm in females), the pale ochreous-brown body and wings coloration (brown in D. reticulata ) and the somewhat wider forewing in males (the length to width ratio is 3.8:1 vs. 2.5: 1 in D. reticulata ). The male genital capsule of D. diktyo sp. n. ( Fig. 17 ) can be distinguished from that of D. reticulata ( Fig. 18 ) by the thicker uncus, the wider valva (the length to width ratio is 3.4:1 vs. 4.4: 1 in D. reticulata ) and the proximally wider distal saccular process (whereas it is constricted proximally in D. reticulata ). The male genital capsule of D. diktyo sp. n. is also reminiscent of those of the superficially dissimilar D. xanthocraspis ( Figs 7, 8 , 19 ) and D. xanthoma ( Figs 5, 6 , 20 ), but differs clearly in the somewhat narrower uncus, the somewhat longer vinculum, the longer (in proportion to the tegumen-vinculum complex length) and narrower (the length to width ratio is 3.4:1 vs. 2.8: 1 in D. xanthocraspis and 2.7: 1 in D. xanthoma ) valva with somewhat narrower distal saccular process bearing finer spinules. The phallus of D. diktyo sp. n. is broader and somewhat longer than in D. reticulata (in proportion to the length of the tegumen-vinculum complex), and proximally broader and more medially curved than in D. xanthocraspis and D. xanthoma . Compared to D. reticulata , D. xanthocraspis and D. xanthoma , the vesica of the new species is broader (in proportion to the genital capsule size), has a small subbasal and a short additional distal diverticulum, somewhat more robust spinules on the lateral diverticulum, and a more ventrally extended main chamber. The female genitalia of D. diktyo sp. n. ( Fig. 26 ) is similar to those of D. reticulata ( Fig. 27 ), but the ductus bursae is somewhat narrower (in comparison to the ovipositor width), the posterior section of the corpus bursae is even (it is longitudinally wrinkled in D. reticulata ), the broader corpus bursae and the round signum (it is elliptical in D. reticulata ). Compared to D. xanthocraspis ( Fig. 28 ) and D. xanthoma ( Fig. 29 ), the female genitalia of D. diktyo sp. n. have a more heavily sclerotized posterior section of corpus bursae, a broader anterior section of corpus bursae with a larger signum, and a somewhat broader (in proportion to the proximal section width) diverticulum of appendix bursae. Additionally, the ductus bursae of the new species is narrower than in D. xanthocraspis .

Distribution. Known from Northern Thailand (Chiang Mai Province).

Etymology. Diktyo is a Latin transliteration of the Greek ‘δικτυώ’ meaning ‘reticulate’. The species name refers to its external similarity to and confusion with D. reticulata .

Figures

FIGURES 1–8. Dolgoma spp.: adults. Depositories of the specimens: 1, 5 and 6 in MWM/ZSM (1 ex CKC); 2–4 in CKC; 7 and 8 in NHMUK (©The Trustees of NHMUK).

FIGURES 17–20. Dolgoma spp.: male genitalia. Depositories of the specimens dissected: 17 and 20 in MWM/ZSM (17 ex CKC); 18 in CKC; 19 in NHMUK (©The Trustees of NHMUK).

FIGURES 26–29. Dolgoma spp.: female genitalia. Depositories of the specimens dissected: 26 and 27 in CKC; 28 in NHMUK (©The Trustees of NHMUK); 29 in MWM/ZSM.