Hypotrabala pruinosa, Takano & László, 2024

Takano, Hitoshi & László, Gyula M., 2024, Descriptions of new Hypotrabala Holland, 1893 (Lepidoptera: Lasiocampidae: Lasiocampinae: Selenepherini) in the collections of the African Natural History Research Trust, with notes on allied genera and the description of a new genus, Ecologica Montenegrina 72, pp. 19-63 : 45-47

Hypotrabala pruinosa sp. n.

https://zoobank.org/ urn:lsid:zoobank.org:act:D6DEC439-37BE-497D-AE80-FBF72BB4D27A

( Figs 50–51 , 68 )

Holotype ♂ ( ANHRT):

“ REPUBLIC OF CONGO 372m / Sangha Prov. , Noubale- Ndoki / National Park, Mbeli camp / ( Gilbertiodendron forest) / 02°14’23.8”N, 16°23’52.1”E / 1-10.x.2022 MV Light Trap / Dérozier, V., Fouka, B., / Kirk-Spriggs, A., Takano, H. Leg. / ANHRT:2022.14 // ANHRTUK / 00290041 // Gen. slide No. / LG 6285 ♂ / prep. by Gy. M. Laszlo [black border; partially handwritten]”

Paratypes (17♂♂):

REPUBLIC OF CONGO: same data as holotype (2♂♂ ANHRT) ; same data but 24 & 26.vi.2022, leg. V. Dérozier (2♂♂ ANHRT) ; same data but 14–20.ii.2023, leg. N.M. Bakala, V. Dérozier, A. KirkSpriggs & G. László (1♂ ANHRT) ; same data but Bomassa , 380m, 02°12’25.7”N, 16°11’39.1”E, 18– 22.vi.2022, leg. V. Dérozier (3♂♂ ANHRT) ; same data but Ndoki formation camp, 352m, 02°12’47.7”N, 16°23’45.8”E, 29.ix–01.x.2022, leg. V. Dérozier, B. Fouka, A. Kirk- Spriggs & H. Takano (5♂♂ ANHRT) ; same data but Mondika camp, 365m, 02°21’50.63”N, 16°16’25.82”E, 07– 14.ii.2023, leg. N.M. Bakala, V. Dérozier, A. Kirk- Spriggs & G. László (4♂♂ ANHRT) .

Description.

Forewing length: holotype: 25 mm; paratypes: 20–25 mm.

Upperside. Ground colour of head and thorax varying from terracotta to charcoal with differing levels of silvery-white irroration; abdomen varying from pale beige to pale brown. Antenna bipectinate, brown. Forewing pointed at apex, outer margin almost straight and angled at tornus. Ground colour of forewing from terracotta to mahogany with varying degrees of silvery-grey irroration. Antemedial fascia dark brown, bilineate, zigzagged the inner line indistinct arising perpendicularly from costa, and angled to terminate perpendicularly along anal margin. Discal spot reniform, silvery-white and ringed in dark brown; the size of the spot and extent of the silvery-white colouration highly variable. Postmedial fascia dark brown, bilineate, gently crenulate, the inner of the two more pronounced; arises perpendicularly from the costa and angled strongly at vein R5, the crenulation becoming greater and terminating along anal margin. Subteminal fascia dark brown with silvery-grey irroration on both edges, irregular, indented broadly running parallel to the outer margin. Terminal area silvery-grey with veins highlighted in pale brownish-white scaling terminating with spots on the termen. Fringe dark grey.

Hindwing outer margin arcuate, almost angled at vein CuA2, gently crenulate; ground colour varying from pale beige to pale brown, becoming darker towards the anal angle. Costa with identical scaling to forewing. Fringe silvery-grey becoming darker towards the tornus.

Underside. Ground colour of head, thorax and abdomen varying from pale beige to terracotta; forelegs darker matching the ground colour of head and thorax on upperside. Ground colour of wings as on upperside but paler basally and lacking much of the silvery-white irroration. Discal spot narrow chevron-shaped pointed proximad, indistinct, white. Postmedian fascia variable, absent in some specimens but when present, the same colour as on the upperside but straighter lacking crenulations. Subterminal fascia as on upperside but less well-defined. Hindwing costal margin with scaling the same colour as forelegs from base to vein Sc+R1. Arcuate postmedian fascia present in some individuals, the same colour as the forewing underside, broadest at costa and petering out towards anal fold.

Male genitalia. Socius long, ca. half as long as valve, arms digitiform with rounded apex, arising far apart from each other, largely diverging at ca. 120° angle. Tegumen moderately long and broad, inner margin evenly arcuate. Valve relatively long, narrow basally, gradually tapered to pointed tip, gently arched dorsad subapically. Juxta with relatively long, pointed posteromedial process. Vinculum narrow ribbon-like medially, with short, truncate lateral plates with straight margins. Phallus short, coecum penis large, as long as sclerotised part of phallus, membranous sack-like, tightly attached to juxta; sclerotised section of phallus slightly dilated medially, curved dorsad, apically pointed. Vesica basally inflated, relatively large, somewhat ovoid, finely scobinate, anteriorly with two long, densely serrate longitudinal plates consisting of fine teeth, forming a V-shape with slightly sigmoidal arms; posterior section of inflated vesica with short, dentate diagonal sclerotisation. Sclerotised plate of eighth sternite anteriorly evenly concave, posteriorly dilated to two short, gently arched plates each bearing short posterior sclerotisation of variable width; plates divided by shallow medial depression.

Diagnosis. Hypotrabala pruinosa is a very distinctive species that cannot readily be confused with any other species having very broad forewings which are almost right-angled at the tornus. Phenotypically, this species displays a great deal of variation, especially in the extent of the silvery-white scaling but this colouration is always present in the terminal area of specimens. It could perhaps be confused with H. lydiae , but the latter has more elongate forewings and the ground colour of the hindwing is a paler cream. In the male genitalia, it is closest to H. indefinita but in the latter, the socii and valves are 20% longer, the socii are distally tapered and apically pointed and the posterior projection of the eighth sternite is shorter.

DNA divergences. The new species has been assigned the BIN BOLD:AEH6351. Intraspecific PWD was 0.0% (n=2) and diverged by 2.2% from the nearest sample ( H. horridula ).

Derivatio nominis. The new species is named in reference to the beautifully frosted appearance of the wings which is particularly noticeable in the holotype.

Figures

Figures 50–59. Hypotrabala species: 50. H. pruinosa sp. n., holotype ♂. 51. Id., paratype ♂. 52. H. indefinita sp. n., holotype ♂. 53. Id., paratype ♂. 54. H. pallens sp. n., holotype ♂. 55. Id., paratype ♂. 56. H. obscura sp. n., holotype ♂. 57. Id., paratype ♂. 58. H. dollmani Tams, 1925, holotype ♂ [NHMUK 010292293]. 59. Id., paratype ♂ [NHMUK 010292327].

Figures 66–71. Male genitalia of Hypotrabala species, a: clasping apparatus, b: lateral view of phallus, c: eighth sternite, d: dorsal view of phallus (a, b, c to scale, d magnified). 66. H. exquisita sp. n., holotype [LG 6307]. 67. H. extenuata sp. n., holotype [LG 6309]. 68. H. pruinosa sp. n., holotype [LG 6285]. 69. H. indefinita sp. n., holotype [LG 6324]. 70. H. pallens sp. n., holotype [LG 6293]. 71. H. ophioglossa sp. n., holotype [LG 6287].