Acronyctodes gabrieli Garzón-Orduña & Matson & Vázquez 2025

Acronyctodes gabrieli Matson Figures 1, 2, 10, 13, 33. https://zoobank.org/NomenclaturalActs/778eaa0e-e797-44f5-85fa-adb2433b3693 Diagnosis. The external anatomy of Acronyctodes gabrieli closely resembles that of its putative sister species, A. leonilaria and A. mexicanaria. However, these species can be partially distinguished by their geographical distributions: A. leonilaria is primarily found in the Mexican Plateau region, A. mexicanaria in the Trans-Mexican Volcanic Belt, Sierra Madre del Sur, and the southern Sierra Madre Oriental, and A. gabrieli appears to be associated with the Sierra Madre Occidental. Like other members of the Mexicanaria-group, the most reliable method of differentiation is through the examination of male genitalia (Granillo-Hernández et al. 2024). Acronyctodes gabrieli is characterized by a narrower, triangular uncus, a large gnathos with a strongly papillated medial process, a highly sclerotized, rugose juxta (see arrow, Figure 10a), and a straight, posteriorly directed, sclerotized process at the end of the aedeagus (see arrow, Figure 10b). In contrast, A. mexicanaria has a thicker, campaniform uncus, a smaller gnathos, a more reduced and less sclerotized juxta (see arrow, Figure 12a), and a curved, sickle-shaped process at the end of the aedeagus (see arrow, Figure 12b). Acronyctodes leonilaria also possesses a campaniform uncus and a smaller gnathos, but its juxta is large and plate-like (see arrow, Figure 11a), and the process at the end of the aedeagus is straight (see arrow, Figure 11b). In females of the Mexicanaria-group (Figures 13–15), the genitalia are largely similar and difficult to differentiate. Acronyctodes gabrieli and A. leonilaria do, however, appear to have a larger, more extended ductus bursae than A. mexicanaria. Although the caterpillars of A. mexicanaria and A. leonilaria are two of the most well-known in Mexico (Granillo-Hernández et al. 2024), there are, so far, no collections of A. gabrieli to compare with these. However, the larva shown in Figure 25 is a potential candidate for this species. Adult. (Figure 2). Forewing length: male: 21–23 mm; female: 23–24 mm. Head: Antenna bipectinate in both sexes; rami of male slightly longer than those of female; scales above black to gray-black. Frons and vertex mostly light grayish-white, however, scales around perimeter of eye dark gray to black. Labial palpus subequal to diameter of eye, light gray to black. Haustellum well-developed. Thorax: Grayish-white. Legs dark gray to black and modestly banded with pale grayish-white scales. Males with small hair pencil tucked inside groove on inner surface of hind tibia. Epiphysis well-developed. Tibial spur formula 0-2-4. Forewing grayish-white with dentate black antemedial and postmedial lines and black discal spot. Medial area between antemedial and postmedial lines of slightly more brown hue. Basal area along costa and post-discal area often blackened in upper third of wing. Basal half of terminal area darker and more brownish-gray than pale grayish-white distal half. Hindwing grayish-white with transverse medial black dentate line and black discal spot. Posterior half of wings lightly speckled with black scales. Undersides of both wings like uppersides but pattern elements and colors more muted. Fringe checkered in both wings. Abdomen: Grayish-white. Male genitalia: (Figure 10). Uncus triangulate. Medial posterior projection of gnathos papillated. Juxta large, highly sclerotized and papillated, and apically blunt. Valve broad and without noticeable acuminate process at apex. Aedeagus with straight, posteriorly directed, sclerotized process between two, lateral, well sclerotized serrate processes; vesica with ca. 30 spinose cornuti in tight cluster. Female genitalia: (Figure 13). Similar to A. leonilaria and A. mexicanaria. Posterior apophysis ca. one third length of anterior apophysis. Sterigma with bulbous lamella postvaginalis bearing concentric folds; lamella antevaginalis wide and sclerotized. Ductus bursae highly sclerotized; manifesting as prominent tongue-like process. Corpus bursae highly sclerotized with longitudinal striations in posterior portion and more membranous and spherical in anterior portion; signum absent. Holotype. ♂, MEXICO: Sonora, Mpo. Nacori Chico, Ejido Mesa Tres Rios, Arroyo La Presita, 3.3km (by air) SSW Mesa Tres Rios, N29°48’33”, W108°43’12” [29.8092°, -108.72°], Pine/oak/cedar riparian woodland, [elev.] 5600 ft, MV light, 5-10-VIII-2018, leg. J. Palting, Molecular Voucher: TAM0219 (MXGEO097-23), [USNM]. Paratypes (8♂, 3♀). 8♂, 3♀, MEXICO: same collection data as holotype except: “Genitalia Slide: TAM-2022- 168 [♂],” “Genitalia Slide: TAM-2023-222 [♀],” “Genitalia Slide: TAM-2023-232 [♂],” “Genitalia Slide: TAM-2023-233 [♀],” [CNIN, USNM]. Distribution. (Fig. 33). So far, A. gabrieli is only known from the Sierra Madre Occidental pine-oak forests at the type locality. However, it is expected to have a distribution that extends southward through the Sierra Madre Occidental. Biology. The immature stages and life history of A. gabrieli remain unknown. However, Figure 25 depicts a potential candidate for its larva: an Acronyctodes caterpillar observed in Urique, Chihuahua. Given that A. gabrieli is the only known Acronyctodes species in the region and the larva’s phenotypic similarity to the closely related A. leonilaria, this specimen is a strong candidate for its caterpillar. Etymology. The specific epithet gabrieli is named in honor of botanist Gabriel Trujillo, who tragically lost his life while conducting his graduate fieldwork in the canyons of Sonora, Mexico. This name serves as a tribute to his legacy, and dedication and passion for botanical research in the very region where this moth, now bearing his name, was discovered. Molecular data. A single specimen of A. gabrieli has been DNA barcoded, revealing a pairwise distance of approximately 2.3% from A. leonilaria and 2.8% from A. mexicanaria. Remarks. One paratype female is missing its abdomen.