Alba moth (Phasmadigonis alba) and Arthur Gardiner Butler moth (Gugnelve butleri) from Andean region

NEWS - Researchers introduced Phasmadigonis Ramos-González & Parra gen. nov. for P. alba (Butler, 1882) comb. nov. and Gugnelve Ramos-González & Parra gen. nov. for G. butleri Ramos-González & Parra sp. nov. Digonis Butler 1882 was reviewed, D. cuprea Butler 1882 was synonymized with D. cervinaria (Blanchard, 1852), all varieties of D. punctifera Butler 1882 and D. cuprea were synonymized with their respective species.

Phasmadigonis was established based on the type species Digonis alba Butler, 1882. This genus has similarities with Digonodes Warren 1895, Digonis Butler 1882, and Gonogala Butler 1882 because of the mucronate wing shape.

However, Phasmadigonis can be distinguished by the presence of the Sc vein connected by a vein to a single accessory cell in the forewing and by the presence of the Sc+R1 vein connected to the radial bar by a weak vein in the hindwing.

Phasmadigonis is distinguished by genitalia: V-shaped gnathos without lobes or spines, spatulate transtillas, broad spade-shaped juxta, furca armed with small sagittal spines and a dimple in the sclerite at the base, aedeagus with a digitiform apex and vesica armed with large spines.

Antennae serrated in males and filiform in females. Thorax and abdomen with grayish scales. Forewings gray-lilac reticulated with white, lacking bands, subterminal region delimited only by a series of blackish spots at the level of R2, R3, R4, M1, M2, M3, CuA1, CuA2, and 1A+2A; costa margin in apical zone is slightly arched; outer margin is concave between apex and M3.

Wing venation: one accessory cell; Sc connected with accessory cell through a short vein, R1 and R2 arise from accessory cell, R3 and R4 are pedunculate, R5 terminates at term; M2 equidistant from M1 and M3, M3 slightly arched and ending in small mucronate apex; CuA1 arises 1/10 before end of cell, CuA2 arises near middle of cell.

Hindwings are paler than forewings, with subterminal region delimited by a series of dark spots at the level of veins. Sc+R1 connected to radial trunk by a weak transverse vein, Rs arises 1/6 before end of cell, M2 is absent. Male genitalia with rod-like uncus; gnathos V-shaped; suboval valves; spatulate transtilla; spiny furca; vesica with prominent spine.

The generic name is formed by combining the Greek words phasma meaning ghost or apparition with Digonis referring to the false resemblance to moths of the genus Digonis Butler and the coloration of its wings. Distribution is similar to that of the only species, P. alba (Butler).

Male P. alba has head: antennae slightly serrated; short palpi, subequal to eye diameter, porrect; fronts and vertex covered with juxtaposed brownish scales. Thorax: patagia covered with elongated scales of same color as background; tegulae covered with piliform scales of same color as background; tibial spur formula 0-2-4.

Forewings: subtriangular with acute apex and outer margin excavated between apex and M3, with a slight mucronated extension; fovea absent; ground color grey-lilac reticulated with white; bands absent, only observable on wing surface are blackish points in subterminal area at the level of veins R2, R3, R4, M1, M2, M3, CuA1, CuA2, and 1A+2A, also visible on ventral side; discal spot visible, punctiform, and blackish.

Hindwings: subrectangular with small mucronated apex at the level of M3; ground color ash-white, termen grayish; bands absent, only observable on wing surface is a row of blackish dots in subterminal area at the level of veins Sc+R1, Rs, M1, M3, CuA1, CuA2, and 1A; discal spot visible.

Uncus straight, apex rod-like; gnathos V-shaped; suboval valvae, valvula and cucullus slightly setose, costa sclerotized; transtilla spatulate with sharp, projected vertices; saccus obcordate; juxta shovel-shaped, dorsally flattened and extended, with finger-shaped furca curved to the left, short, not surpassing the height of the transtilla,, densely spiny sagittally; anellus sclerite weakly defined. Aedeagus tubular, straight, apex digitiform; vesica armed with a large spine.

This species is found between the provinces of Cachapoal and Chiloé (Chile) and Río Negro (Argentina). Distributed in parts of the biogeographic province of Santiago (Central Chile subregion), the Maule and Valdivian Forests (Subantarctic subregion of the Andes region) . Specimens were caught in December, January, February and March. There are no records for other months.

Gugnelve was established based on the type species Gugnelve butleri Ramos-González & Parra, sp. nov. Externally, Gugnelve resembles Euangerona Butler and Dectochilus Warren. All three genera has an oblique curved band in the middle area of the forewings. However, Gugnelve has smooth and slightly curved wingtips (vs. Euangerona and Dectochilus have wavy wingtips).

The wing and antennae are similar in shape to Laninia Orfila & Schajovskoy and Macrolyrcea Butler, but both differ significantly in various genital structures, such as the gnathos with posteriorly directed wing tips and distally lobulated costa in Laninia and the spatulate uncus and oval valves in width in Macrolyrcea.

The V-shaped gnathos with rows of elongate spicules is reminiscent of Euangerona and Dectochilus, but in both genera the anellus processes are oriented anteriorly (vs. posteriorly oriented in Gugnelve).

The uncus and juxta are similar to Malleco Rindge, but Gugnelve has a glabrous uncus and trifid anellus processes (vs. Malleco with the gnathos having numerous spicules on the lateral arms and apex). Finally, the new genus differs significantly in external and genitalia characters from other Andean Nacophorini such as Catophoenissa Warren 1894, Catocalopsis Rindge 1971, Talca Rindge 1971 and Wichanraran Parra 2018.

Gugnelve is distinguished by V-shaped gnathos with a row of 11 spicules at the apex, bifurcated transtilla, lance-shaped juxta that extend laterally into a pair of three-spined anellus processes, heavily sclerotized and glabrous, vesica armed with a series of cornuti, signum with long blade-like ridges on sclerotized patches.

Gugnelve has antennae thickened and slightly serrated in males, filiform in females. Robust thorax with yellowish brown piliform scales. Abdomen with belt of white scales on A1 and A2. Forewings yellowish brown, subtriangular, slightly falcate, with sinuous and inclined antemedial and postmedial bands.

Two accessory cells, second twice as long as first; Sc in contact with first accessory cell, R1 originates from middle of second accessory cell, R2 and R3+4 connate, R3 and R4 pedunculate, R5 terminates at termen; M2 equidistant from M1 and M3, M3 slightly arched; CuA1 originates 1/8 before end of cell, CuA2 originates near middle of cell.

Hindwings paler than forewings, with yellowish brown piliform scales on the termen. Sc+R1 in contact with radial trunk up to middle of cell, Rs originates 1/12 before end of cell, M2 absent.

Male genitalia with V-shaped gnathos, expanded apex with 11 small variably-sized denticles towards the center; sub-rhomboidal valves; juxta sub-halberd-shaped, laterally extended into a pair of tri-spined, strongly sclerotized processes. Female genitalia with signum with long blade-like ridge on sclerotized patch.

The generic name is from the Mapudungun language (spoken by the Mapuche, the largest indigenous group in Chile), wüṉyelfe meaning bright star or Venus in reference to its yellowish color. The only species is G. butleri Ramos-González & Parra sp. nov.

Male G. butleri has head: antennae slightly serrated; palpi short, subequal to the eye diameter, porrect; fronts and vertex covered with juxtaposed brownish scales. Thorax: Patagia covered with elongated scales of same color as background; tegulae covered with piliform scales of same color as background; tibial spur formula 0-2-4.

Forewings: slightly falcate, subtriangular; fovea absent; background color yellowish brown; antemedial band dark yellowish brown, externally bordered by pale brown, oblique, extending toward the medial area, near the end of the discal cell where it curves toward the antemedial sector to the costa, forming an acute arc; postmedial band dark yellowish brown, externally bordered by pale brown, slightly sinuous, oblique, and slightly curved, extending to the subapical sector; discal spot not visible. Hindwings: suboval; background color pale brown without bands; discal spot not visible.

Uncus conical; socii slightly setose; gnathos V-shaped with sinuous arms, expanded apex with 11 small denticles of varying sizes toward the center; sub-rhomboidal valvae, costa and anterior margin sclerotized; transtilla fork-shaped; suboval sac; juxta sub-halberd-shaped, laterally extended into a pair of tri-spined strongly sclerotized processes; anellus sclerite weakly defined. Tubular aedeagus, straight; vesica armed with cornuti, formed by 11 grouped spines of different sizes.

Female similar to male but with simple filiform antennae, dark yellowish brown falcate forewings, and slightly crenulated pale brownish gray subrectangular hindwings. Ductus bursae half the length of the corpus bursae; funnel-like antrum; corpus bursae membranous, subpyriform, signum with a long blade-like ridge on a sclerotized patch; posterior apophyses three times longer than anterior apophyses.

The specific name is dedicated to Arthur Gardiner Butler, a 19th-century ornithologist, arachnologist and entomologist of contribution to the study of Lepidoptera in Chile.

This species is found between the provinces of Limarí and Talca. It is distributed in parts of the biogeographic provinces of Coquimbo and Santiago (Central Chile subregion), Maule (Subantarctic subregion) in the Andean region. The specimens were captured in November, December and January . There are no records for other months.

Original research

Ramos-González MI, Venegas-González MF, Zamora-Manzur C, Parra LE (2024). Revision of the genus Digonis (Lepidoptera, Geometridae): new species and new genera. ZooKeys 1216: 173-200, DOI:10.3897/zookeys.1216.129923

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