Acronyctodes bisbili Murillo-Vázquez, 2025

Acronyctodes bisbili Murillo-Vázquez

Figures 1 View FIGURE 1 , 9 View FIGURES 2–9 , 20 View FIGURES 16–20 , 27 View FIGURES 25–32 , 35 View FIGURES 33–36 .

https://zoobank.org/NomenclaturalActs/2d80d71f-9336-4ce8-80fa-5b7d87b1e596

Diagnosis. Acronyctodes bisbili is the smallest known species of the genus ( Fig. 9 View FIGURES 2–9 ), with male forewing lengths of 17–20 mm (n=3). Currently, this species is only documented from the highlands of Chiapas, and its full distribution remains unclear. As with other species of Acronyctodes , the wing color pattern in A. bisbili does not appear to be diagnostic ( Granillo-Hernández et al. 2024). However, the species can be reliably identified by features of the male genitalia, particularly its small size and unique structures. The uncus of A. bisbili is shorter and thinner with a triangular shape, whereas A. corrugata has a longer, thicker uncus. Additionally, the gnathos in A. corrugata is less expanded in its middle compared to A. bisbili . The most distinctive feature of the species lies in the number and arrangement of cornuti: A. corrugata has 10–15 cornuti arranged in a mostly linear pattern, whereas A. bisbili exhibits a dense, non-linear cluster of approximately 25–30 cornuti arranged at an acute angle.

Adult. ( Figure 9 View FIGURES 2–9 ). Forewing length: male: 17–20 mm.

Head: Covered by mostly brownish scales, antenna bipectinate. Vertex uniformly cream-colored. Labial palpus ochre-brown, equal to or longer than diameter of eye. Haustellum well-developed (± 10 mm).

Thorax: Brownish. Legs with white and ochre scales. Epiphyses well-developed. Tibial spur formula 0-2- 4. Forewing greenish-brown, with bold white subterminal zigzagged line and dark brown basal line. Greenish-brown discal spot in subapical area. Medial area between subterminal and basal lines with greenish-brown shades. Upperside of hindwing with dark brown and golden scales. Postmedial dentate line darker brown bordered by white scales. Underside of hindwing homogeneously beige and patterned with thin faint line in medial area and discontinuous dotted postmedial line.

Abdomen: Pale gray to tan.

Male genitalia: ( Figure 20 View FIGURES 16–20 ). Uncus triangulate and campanulated, ending in a beak shaped tip. Gnathos looped with sclerotized median area denticulate or spinulose. Valva broad with sclerotized costal margin and distal end finishing in spine-like border, internal region covered by long thin setae. Juxta rounded at base, extending ventrally ending as a cuspid or triangular process. Aedeagus short, thin, without processes, ending in finger-like extension. Vesica with ca. 25–30 spinose cornuti in a tight cluster arising from the opposite side of the caecum penis (basal opening of phallus) ( Fig. 20b View FIGURES 16–20 ).

Larva:( Fig.27 View FIGURES 25–32 ) Head dark grey with black spots.Body creamy yellow with broad light grey dorsal,supraspiracular, subspiracular and ventral stripes, each bordered on each side by thin black stripes. White and yellow spiracular area, with some black spots around the spiracles, which turn orange from the sternite A6.

The pale colour of the head and body in Figure 27 View FIGURES 25–32 could be the result of a molting larva. The caterpillar may be darker. The larva resembles A. corrugata , although our specimens of the latter have more pronounced black spots in the spiracular area. More larvae of both species are needed to draw definitive diagnostic conclusions.

Holotype. ♂, MEXICO: Chiapas, Mpio. San Cristóbal de Las Casas, Parque Montetik, N16º40’55.2”, W92º35’56.4” [16.682º, -92.599º], Pine/oak woodland, [elev.] 7874 ft, MV light, 20-21-VII-2022, leg. IJ Garzón, TA Matson, FR Joele & JJ Dombroskie. GoogleMaps

Paratypes. 2♂, same locality as holotype GoogleMaps .

Distribution. ( Fig. 35 View FIGURES 33–36 ). The range of Acronyctodes bisbili remains unclarified. Thus far, it is only known from the type locality in the pine-oak forests of San Cristóbal de las Casas, Chiapas.

Biology. A larva of Acronyctodes bisbili ( Fig. 27 View FIGURES 25–32 ) was collected from Tepozan ( Buddleja cordata Kunth ) ( Scrophulariaceae ) in late July of 2022 by authors TAM and IJGO. The larva struggled and was preserved in alcohol. A proleg was later sequenced to confirm its identity.

Etymology. The name bisbili means “striped” in Tzeltal, an indigenous language of the Chiapan Highlands. The name references the striped pattern of the caterpillar.

Molecular data. Three specimens of Acronyctodes bisbili were sequenced, including one larva and two adults. These specimens are assigned to BIN BOLD: AFA3106 , which exhibits a pairwise genetic distance of approximately 4% from its nearest neighbor, Acronyctodes corrugata ( BIN BOLD: AAZ5681 ).

Remarks. The female of A. bisbili remains unknown. Additionally, the larval description, based on a single molting individual, should be interpreted with caution.