Hypeugoa radaricola, Karel Cerny, 2009

Volynkin, Anton V. & Černý, Karel, 2021, On the taxonomic status of the genus Hypeugoa Leech with description of a new species of Miltochrista Hübner from Thailand (Lepidoptera: Erebidae: Arctiinae Lithosiini), Zootaxa 5023 (3), pp. 421-432 : 425-426

The radaricola species-group

Diagnosis. The two known species of this group differ from congeners in their brown wing coloration which is reddish, yellowish or whitish in other species-groups. The male genitalia are characterized by the combination of the following features: (1) the swollen medial section of the costa, (2) the absence of a distal costal process and (3) the presence of only one cornutus positioned in the distal end of the main chamber of the vesica. The female genitalia are characterized by the short antrum, the large (in proportion to the corpus bursae) elliptical signum, and the twisted appendix bursae (the feature unique within the genus). The male genitalia are most similar to those of the M. testata species-group the detailed comparison with which is provided under the diagnosis of M. radaricola .

External morphology of adults ( Figs 11–14 ). Forewing length 10–12.5 mm in males and 13–15 mm in females. Male antenna densely ciliate while female one sparsely ciliate with shorter ciliae. Sexual dimorphism limited: female somewhat darker coloration. Head and thorax dark brown. Forewing wide (length to width ratio from 1.5:1 to 1.85:1). Forewing ground color brown. Pattern diffuse, dark brown. Antemedial line sinuous, outlined with pale ochreous scales. Medial line sinuous and indistinct. Discal spot round, distinct. Postmedial line strongly zigzagged, outlined with pale ochreous scales. Subterminal and terminal lines diffuse, may be interrupted into spots on veins. Cilia dark brown with pale ochreous spots opposite veins. Hindwing pale brown, with diffuse brown antemedial, medial and terminal fasciae. Cilia pale brown with pale ochreous spots opposite veins. Abdomen pale brown.

Male genitalia ( Figs 21–23 ). Uncus slender, elongate, somewhat curved medially and apically pointed. Tuba analis broad (ca. 1/3 of tegumen length), scaphium thin. Tegumen with distally dilated arms fused in apical third. Vinculum somewhat shorter than tegumen, with more or less U-shaped saccus. Juxta rectangular with shallow round basal incision and two oblique medial crests. Transtillae fused, band-like. Valva elongate and slightly dilated distally. Costa straight with swollen medial section, thin apical section fused with distal membranous lobe and narrow ventral protrusion along the base of distal membranous lobe reaching the base of distal saccular process. Sacculus broad basally (more or less equal in width with basal section of valva) and strongly tapered distally with setose dorsal margin basally and medially. Distal saccular process slender, elongate and apically pointed, straight or curved. Phallus long (from 0.6 to 0.7 of tegumen-vinculum complex length) and moderately broad (length to width ratio from 2.6:1 to 3:1), somewhat dilated proximally. Vesica broad (in proportion to phallus width), with short but broad diverticula bearing fields of granulation and a terminal cornutus.

Female genitalia ( Fig. 28 ). Papillae anales trapezoid, weakly setose. Apophyses elongate and thin, equal in length. Antrum short (ca. 1/3 of ductus bursae length), trapezoid ventrally with round plate dorsally. Ductus bursae membranous, somewhat narrower than antrum. Corpus bursae sack-shaped with fields of scobination anteriorly and posteriorly, transverse weakly sclerotized band-like signum medially and serrate elliptical signum anteriorly. Appendix bursae elongate (ca. half of corpus bursae length), twisted, weakly gelatinous with fields of scobination basally and subapically.

Distribution. The two known members of the species-group are distributed in Thailand.

Figures

FIGURES 9–16. Stigmatophora micans (9, 10) and Miltochrista spp. (11–16): adults. Depositories of the specimens: 9–11, 13, 15 and 16 in MWM/ZSM (13 ex CAV); 12 in CKC; 14 in CAV.

FIGURES 21–24. Miltochrista spp.: male genitalia. All deposited in MWM/ZSM.

FIGURES 25–29. Stigmatophora (25–27) and Miltochrista (28, 29) spp.: female genitalia. Depositories of the specimens dissected: 25, 26 and 29 in MWM/ZSM; 27 in CAV; 28 in CKC.