Tyrictaca pulchra, O. Gorbunov, 2022

Gorbunov, Oleg G., 2022, A new species of the genus Tyrictaca Walker, 1862 (Lepidoptera: Sesiidae) from West Malaysia with a catalogue of the genus, Zootaxa 5104 (1), pp. 125-136 : 126-130

Tyrictaca pulchra sp. nov.

( Figs 1–16 )

Holotype ♂ ( Figs 1–2 , 7, 8 , 13 ), “W. Malaysia, Selangor, / Gohtong Jaya ( Skyway ). / 820 m, 03˚25΄N, 101˚46΄E, / 29.IV.2011, / O. Gorbunov leg.”; “ SESIIDAE / Pictures №№ / 0305-0306–2013 / Photo by O. Gorbunov ”; “HOLOTYPUS ♂ / Tyrictaca pulchra / O. Gorbunov, 2022 / O. Gorbunov des., 2020” ( COGM).

Paratypes (3 ♂♂): 1 ♂ ( Figs 3–4 , 15 ), “W. Malaysia, Selangor, / Gohtong Jaya ( Skyway ). / 820 m, 03˚25΄N, 101˚46΄E, / 29.IV.2011, / O. Gorbunov leg.”; “ SESIIDAE / Pictures №№ / 0307-0308–2013 / Photo by O. Gorbunov”; “ PARATYPUS ♂ / Tyrictaca pulchra / O. Gorbunov, 2022 / O. Gorbunov des., 2020” ( COGM) ; 1 ♂ ( Figs 5–6 , 14 ), “W. Malaysia, Selangor, / Gohtong Jaya , 1000 m, / 03˚24΄N, 101˚46΄E, / 29–30.IV.2011, / O. Gorbunov leg.”; “ SESIIDAE / Pictures №№ / 0511-0512–2021 / Photo by O. Gorbunov ”; “ PARATYPUS ♂ / Tyrictaca pulchra / O. Gorbunov, 2022 / O. Gorbunov des., 2020” ( COGM) ; 1 ♂ ( Fig. 9–12 , 16 ), “W. Malaysia, Pahang, / Genting Highland , 800–1000 m, / 03˚23΄N, 101˚47΄E, / 17–23.X.2010, / V. Tuzov leg.”; “Genitalia examined / by O. Gorbunov / Preparation № / OG–016-2021”; “ PARATYPUS ♂ / Tyrictaca pulchra / O. Gorbunov, 2022 / O. Gorbunov des., 2020” ( COGM) .

Description. Male (holotype) ( Figs 1–2 ). Alar expanse 15.2 mm; body length 6.8 mm; forewing 6.0 mm; antenna 4.5 mm.

Head with antenna black with dark violet sheen dorsally and light brown ventrally, scapus black with dark violet sheen and a few dark grey scales posteriorly; frons brownish-grey with bronze-violet sheen; vertex dark brown to black with bronze-violet sheen, scales of vertex overlapping dorsal third of frons; two basal joints of labial palpus dark brown with dark violet sheen, apical joint white ventrally and light brown dorsally; occipital fringe black with blue-violet sheen dorsally and silvery-white laterally ( Fig. 7 ); neck plate dark grey-brown with greenish-violet sheen.

Thorax with patagia dark brown with bronze-violet sheen and a few white scales laterally; tegula dark brown to black with greenish-bronze sheen; meta- and mesothorax entirely dark brown to black with bronze-violet sheen; thorax laterally dark brown to black with bright greenish-violet sheen; posteriorly both metepimeron and metameron smooth scaled, dark brown with bright violet sheen and a few white scales ventrally. Legs with fore coxa dark grey-brown with bronze-violet sheen and a few light brown scales at external margin; fore femur entirely dark grey-brown with bronze-violet sheen; fore tibia black with bright violet sheen and a few light brown scales dorsally and dirty yellow with golden sheen ventrally; fore tarsus reddish with an admixture of individual black scales with bright violet sheen dorsally; mid coxa and mid femur entirely dark grey-brown with bronze-violet sheen; mid tibia dark grey-brown with bright bronze-violet sheen and with two tufts of elongated scales exterior-dorsally; spurs dark grey-brown with bright violet sheen externally and grey with silvery sheen internally; mid tarsus reddish with bronze sheen, with an admixture of individual black scales with violet sheen and with a tuft of black elongated scales with bright violet sheen dorsally on basal tarsomere; hind coxa silvery white with a few dark grey-brown scales with violet sheen anteriorly; hind femur entirely dark grey-brown with violet sheen; hind tibia black with bright greenish-violet sheen, with a narrow white line between bases of both pairs of spurs and with a few reddish elongated and pointed scales dorsally both at level of mid spurs and distally; dark grey-brown with bright violet sheen externally and greyish white with silvery sheen internally; basal hind tarsomere exterior-dorsally covered with yellow and a few white elongated scales, remaining tarsomeres dark grey-brown with violet sheen dorsally and reddish to dark orange ventrally. Forewing completely covered by scales; dorsally from base to level of crossvein dark brown to black with greenish-violet sheen and a few light brown scales with golden sheen distally; costal margin between veins Sc and R 4 white, CuA-stem and anal margin with a few grey scales with bright electric blueviolet sheen; remaining surface semitransparent with yellowish glitter; veins R 4 –M 3 yellowish in basal half and dark brown in distal half; extremely narrow outer margin dark brown; cilia between veins R 4 –M 3 dark brown and white in remaining part; ventrally dark brown with bright violet sheen, remaining surface white with weak yellowish glitter; cilia white. Hindwing transparent in basal quarter and scaly in remaining part; medially broadly brown with greenish-gold sheen, distally semitransparent with yellowish glitter; cilia from costal margin to vein CuA 1 white, remaining part dark brown.

Abdomen dorsally tergites 1–4 each dark brown to black with dark violet sheen; tergite 1 with a small white spot laterally; tergites 5 and 6 each dark grey-brown with greenish-blue sheen and a few light brown scales; tergite 7 white with yellowish tint; ventrally sternites 1–5 dark grey-brown with bright violet sheen; sternites 6 and 7 white with yellowish tint; medial part of anal tuft small white with yellowish tint, lateral parts well-developed, reddish to light brown with golden glitter and a narrow dark brown stripe ventrally ( Fig. 8 ).

Male genitalia (paratype, genital preparation № OG–016-2021) ( Figs 9–12 ). Tegumen-uncus complex relatively broad; uncus finger-shaped, well-sclerotized, sparsely covered with long and short hair-like setae, apically with a strong beak-shaped tooth downwards; tuba analis with scaphium undeveloped, subscaphium narrow wellsclerotized ( Fig. 9 ); valva ( Fig. 10 ) semi-oval, densely covered with hair-like setae of various lengths on inner surface; saccus ( Fig. 11 ) short and broad, rounded basally; vinculum short ( Fig. 11 ); phallus ( Fig. 12 ) relatively broad and long, about 1.75 as long as valva, coecum penis nearly undeveloped, bulbus ejaculatoris long and broad, vesica with two distinct areas of minute spins.

Female. Unknown.

Individual variability. The specimens slightly varying in the number of light brown scales with golden sheen basally of cross-vein and grey scales with bright electric blue-violet sheen on the forewing and in the number of brown with greenish-gold sheen scales on the hindwing ( Figs 13–16 ). Besides this, this new species is slightly variable in individual size: alar expanse: 15.1–15.5 mm; body length 6.8–8.1 mm; forewing 6.0–6.8; antenna 3.9–4.5 mm.

Differential diagnosis. Habitually, this new species is somewhat similar to Tyrictaca apicalis Walker, 1862 , from which it can be distinguished by the colouration of the hind tarsus (basal hind tarsomere exterior-dorsally covered with yellow and a few white elongated scales, remaining tarsomeres dark grey-brown with violet sheen dorsally and reddish to dark orange ventrally in T. pulchra sp. nov., vs. entirely dark brown with purple sheen, without any reddish or yellow scales in T. apicalis ) and by the character of the scaly cover of both fore- and hindwing (cp. Figs 1–6 , 13–16 with fig. 422a in Arita et al. 2021: 183). T. pulchra sp. nov. is clearly separated from T. mesatma ( Meyrick, 1926) by the colouration of the labial palpus (two basal joints dark brown with dark violet sheen, apical joint white ventrally and light brown dorsally in T. pulchra sp. nov., vs. entirely pale fulvous in T. mesatma ), thorax dorsally (patagia dark brown with bronze-violet sheen and a few white scales laterally; tegula dark brown to black with greenish-bronze sheen; meta- and mesothorax entirely dark brown to black with bronze-violet sheen in T. pulchra sp. nov., vs. blackish moxed fulvous-brown in the species compared), abdomen dorsally (tergites 1–4 each dark brown to black with dark violet sheen; tergite 1 with a small white spot laterally; tergites 5 and 6 each dark grey-brown with greenish-blue sheen and a few light brown scales; tergite 7 white with yellowish tint; anal tuft white with yellowish tint, lateral parts well-developed, reddish to light brown with golden glitter and a narrow dark brown stripe ventrally T. pulchra sp. nov., vs. abdomen dorsally blackish mixed brown, tergites 3–5 each with a small fulvous-brown spot; anal tuft fulvous-brown suffused dark fuscous at tip in T. mesatma ), by the undeveloped discal spot of the forewing and broad darkening on the hindwing medially (cp. Figs Figs 1–6 , 13–16 with fig. 27a in Arita et al. 2021: 58). From all other congeners, T. pulchra sp. nov. clearly differs by the broad darkening on the central part of the hindwing and by the colouration of the anal tuft.

Bionomics. The larval host plant is unknown. The males of the type series were attracted by nonspecific artificial sex pheromones. They came to lures at noon and somewhat later (12– 2 p. m.).

Habitat. The type series was collected at the border of Upper dipterocarp forest at 800–1000 m a.s.l. with Shorea sp. , Dipterocarpus sp. (Dipterocarpaceae) , Agathis borneensis Warb. (Araucariaceae) and Calophyllum sp. (Clusiaceae) as dominant species ( Fig. 17 ).

Distribution. The new species is known only from the vicinity of the Genting Highlands in the states of Selangor and Pahang, West Malaysia.

Etymology. The name of this new species comes from the Latin “pulchra”, which means beautiful and matches its appearance.

Note. Unfortunately, the behavior of this new species remains unknown, but in its external appearance it is very similar to the bee Tetragonilla collina (Smith, 1857) (Apidae) . Obviously, they form a very good mimic pair.

Figures

FIGURE 17. Habitat of Tyrictaca pulchra, sp. nov. near Skyway Stantion, Gohtong Jaya, Selangor, West Malaysia, 820 m, 03˚25΄N, 101˚46΄E, 29.IV.2011.

FIGURES 1–6. Variability of males Tyrictaca pulchra, sp. nov.: 1–2) holotype, alar expanse 15.2 mm, Sesiidae picture № 0305–0306–2013; 3–4) paratype, alar expanse 15.1 mm, Sesiidae picture № 0307–0308–2013; 5–6) paratype, alar expanse 15.5 mm, Sesiidae picture № 0511–0512–2021; 1, 3, 5—dorsal view; 2, 4, 6—ventral view.

FIGURES 7–8. Details of the body of the holotype of Tyrictaca pulchra, sp. nov.: 7) head, lateral view; 8) lateral lobe of the anal tuft.

FIGURES 9–12. Male genitalia of Tyrictaca pulchra, sp. nov. Paratype. Genital preparation № OG–016-2021. 9) tegumentuncus complex; 10) valva; 11) saccus; 12) phallus. Scale bar: 0.5 mm.

FIGURES 13–16. Variability of the scaly cover of the wings of Tyrictaca pulchra, sp. nov. 13) holotype. 14–16) paratypes.