Isocossus zolotuhini Yakovlev

Yakovlev, Roman V., 2015, A new species of Isocossus Roepke, 1957 (Lepidoptera: Cossidae) from Vietnam, including a world catalogue of the genus, Zootaxa 3990 (1), pp. 141-146 : 142

Isocossus zolotuhini Yakovlev , sp. nov.

( Figs 1 , 12, 13−14 )

Type material. Holotype: male, C[entral]. Vietnam, Thue Thien Hue Prov., A Ruang, 663 m, 16°04’N; 107°51’E, 24– 27.0 4.2009, leg. V. Zolotuhin & A. Gurkovich (MWM); paratype: male, same locality and data (RYB).

Diagnosis. The new species most closely resembles I. retak and I. vandeldeni , but is readily distinguished by the structure of the male genitalia. It differs from I. retak by more developed sacculus along with slightly curved costal edge of valva and more massive processes of transtilla, and from I. vandeldeni by longer processes of the transtilla, the smooth dorsal edge of valve, and thin uncus.

Description. Forewing length 24 mm in the holotype (22 mm in the paratype), wingspan 52 mm in the holotype (49 mm in the paratype). Antennae bipectinate, processes of antenna strongly cut in distal third (in comparison with length of processes of proximal part of antenna). Tegula pale brown. Thorax with spot of flour white hairs from above. Forewing rather narrow, with rounded apex, flour white with fine grey pattern, base of forewing with rounded black spot on costal edge. All area of forewing with fine grey wavy pattern. Cubital zone of forewing discal area with light brown field. Hindwing grey without pattern. Fringe of both wings checkered, dark near veins and pale between them.

Male genitalia typical for the genus, uncus stout with slightly developed incisure; tegumen medium-sized; branches of gnathos rather stout, medium-sized; gnathos stout, densely covered by small thorns; processes of transtilla massive, hook-like, with thick bases and pointed tips, as long as 1/3 of valva; juxta small, heavily sclerotized, with long oar-like lateral processes situated at 100º to each other, length of juxta processes equal to length of transtilla processes; valvae rather broad, with well-developed sacculus, their distal fourth membranous, transition zone between proximal sclerotized part and distal membranous part unsharp, costal edge of valva slightly curved; saccus semicircular, rather massive. Aedeagus thick, strongly arched at medium third, slightly shorter than valva, pore of vesica in dorso-apical position and occupying 2/5 of aedeagus length, vesica without cornuti.

Female unknown.

Etymology. The new species is named after a well known Russian lepidopterist Dr. Vadim Zolotuhin (Ulyanovsk), a specialist in Macroheterocera.

Ecology. Specimens were attracted by light trap at the end of April, in a primary tropical forest at 663 m.

Figures

FIGURES 1 − 11. 1. Isocossus zolotuhini Yakovlev, sp. nov., holotype, male. 2. Isocossus cruciatus (Holloway, 1986), holotype, male. 3. Isocossus seria (Holloway, 1986), holotype, male. 4. Isocossus stroehli Yakovlev, 2006, holotype, male. 5. Isocossus stroehli Yakovlev, 2006, paratype, male, Malaysia, Cameron Highlands, SW Ringlet (Brücke), 650 m, 4 ° 21 ’ 36 ’’ N; 101 ° 20 ’ 52 ’’ E, 12. – 21. 0 7. 2001. leg. Ströhle (MSW). 6. Isocossus retak (Holloway, 1986), holotype, male. 7. Isocossus rufipecten (Holloway, 1986), holotype, male. 8. Isocossus telisai (Holloway, 1986), holotype, male. 9. Isocossus telisai (Holloway, 1986), male, Borneo, Sabah prov., Trus Madi bei Apin Apin, 1080 m, 21.03. – 12.04.2006, leg. K. Martini (MWM). 10. Isocossus vandeldeni Roepke, 1957, holotype, male. 11. Isocossus vandeldeni Roepke, 1957, male, Borneo, Sabah prov., Trus Madi bei Apin Apin, 1080 m, 21.03. – 12. 0 4. 2006, leg. K. Martini (MWM).

FIGURES 12 − 14. 12. Genitalia of holotype of Isocossus zolotuhini Yakovlev, sp. nov. 13. Distribution of Genus Isocossus Roepke, 1957. 14. Type locality (Thue Thien Hue Prov., A Ruang) of Isocossus zolotuhini Yakovlev, sp. nov. (photo by Vadim Zolotuhin)