Spilarctia procedra oudomsayensis Spitsyn & Potapov, 2020

Spitsyn, Vitaly M. & Potapov, Grigory S., 2020, Spilarctia procedra oudomsayensis ssp. nov. from Laos (Lepidoptera: Erebidae: Arctiinae), Ecologica Montenegrina 27, pp. 90-94 : 92-93

Spilarctia procedra oudomsayensis Spitsyn & Potapov ssp. nov.

Figs. 2 A-2D, 3A

Type material. Holotype male, LAOS: Oudomxay Province, Muang Xay City , tropical forest with bamboo patches, 20°39’04”N, 101°58’18”E, 04-06.V.2016, Spitsyn leg. ( RMBH, voucher no. Sph0813) . Paratype female, Oudomxay Province, Muang Xay City , damaged forest on the border of the city, 20°39’46”N, 101°58’14E, 01-03.V.2016, Spitsyn leg. ( RMBH, voucher no. Sph0814) .

Diagnosis. Spilarctia procedra oudomsayensis ssp. nov. differs from the nominative subspecies by the absence of a dashed line in the postdiscal area of the forewing, by converging spots at the costal margin and at the apex of the central cell, as well as by a more pronounced series of spots in the marginal part of the hindwings. Of the closely related species in the north of Indochina, it is known only two species, i.e. Spilarctia gopara (Moore, 1859) and S. ummera Swinhoe, 1889 ( Fig. 1 E-1F). S. procedra oudomsayensis ssp. nov. differs from S. gopara in the absence of a black field on the hindwing, as well as a small number of spots on the forewing ( Fig. 1 A-E). Additionally, S. procedra oudomsayensis ssp. nov. can be distinguished by very short branches on the inner side of the antenna (significantly less than half of the branches length on the outer side of the antenna). The branches on the inner side of the antenna of S. gopara are about half of the branches length on the outer side of the antenna. The male genitalia are very similar, however S. procedra oudomsayensis ssp. nov. differs from the other taxa by broader genitalia with broad valva, and it has differences in the structure of the juxta, the upper side of which does not have a concave center ( Fig. 2 A- B). S. procedra oudomsayensis ssp. nov. differs from S. ummera by the presence of spots in the marginal part of the hindwing, as well as in the specific structure of the male genitalia (valva of S. ummera are expanded in the apical part, while valva of S. procedra oudomsayensis ssp.nov. does not have such an extension) ( Fig. 1 A-D, F, 2A, C). The male genitalia and the external morphology of the nominative subspecies of S. procedra are illustrated by Dubatolov (2006).

Description. Male morphology: Wingspan 34 mm, forewing length 16 mm. Eye black. Antenna black, branches on the inner side of the antenna very short (significantly less than half of the branches length on the outer side of the antenna). Frons white with black spots near eyes. Vertex white. Labial palpus relatively long (longer than eye diameter), orange, apex and dorsal side black. Proboscis short. Thorax, patagium and tegula whitish gray. Ventral side of thorax orange. Legs bicolor; coxa, trochanter and femur orange; tibia and tarsus gray (the inner side orange); on the coxa of forelegs is large gray elongated spot. Forewings light brown with 5 black dots. One point located at the base, two others on the costal vein (dividing it into approximately three equal parts) and two very small points located in the apex of the central cell and above the bend of anal vein. Underside of the forewing light brown with orange tint and a spot in the apex of the central cell. Hindwing orange with a series of black spots in the marginal part of the wing and one round spot in the apex of the central cell. Underside of hindwing follows the pattern of the upper side. Upper part of abdomen orange with a row of black dots on the top. Tip of abdomen white. Underside of abdomen white with 2 rows of black spots on sides. Male genitalia: Tegumen large and broad. Uncus large and wide, slightly curved in apical part. Saccus large, wide, rounded. Valva elongated. Juxta broad; upper edge straight, without a notch. Aedeagus long, has a sclerotized area in apical part. Vesica relatively small; medial diverticulum has a granulose field. Female morphology: Wingspan 47 mm, forewing length 24 mm. The color is similar to the color of the male, except for the absence of an upper spot on the costal vein of the forewing. The inner surface of the legs is white-gray. The antenna structure of the female is not known. Female genitalia: not studied.

Distribution. Only known from the type locality, in the Oudomxay Province of Laos ( Fig. 3 ).

Etymology. The name of this subspecies refers to the type locality, i.e. the Oudomxay Province of Laos.

Figures

Figure 1. Spilarctia spp.: A-D S. procedra oudomsayensis ssp. nov.: A) holotype male, upperside; B) holotype male, underside; C) paratype female, upperside; D) paratype female, underside. E) Male specimen of S. gopara (Moore, 1859) (Myanmar); F) Male specimen of S. ummera Swinhoe, 1889 (N. Thailand).

Figure 2. Male genitalia and aedeagus of Spilarctia spp.: A) S. procedra oudomsayensis ssp. nov., holotype; B) S. gopara (Moore, 1859); C) S. ummera Swinhoe, 1889.

Figure 3. Distribution of Spilarctia procedra (Swinhoe, 1907): the red filling indicates the range of S. procedra procedra; the red circle indicates the type locality of Spilarctia procedra oudomsayensis ssp. nov.