Acronyctodes corrugata Matson and Garzón-Orduña

Acronyctodes corrugata Matson and Garzón-Orduña

Figures 1 View FIGURE 1 , 6 View FIGURES 2–9 , 17 View FIGURES 16–20 , 22 View FIGURES 21–24 , 28 View FIGURES 25–32 , 36 View FIGURES 33–36 .

https://zoobank.org/NomenclaturalActs/3c455016-686f-4e11-a671-b40cea14e1c8

Diagnosis. Acronyctodes corrugata cannot be reliably distinguished from A. cautama , A. colorata , and A. asignum based on external appearance alone. Confidence in identification typically requires genitalic dissection and/or DNA barcoding. Our limited sampling suggests that A. corrugata ranges more widely across the Central American montane and pine-oak forests of southern Mexico, Guatemala, El Salvador, Honduras, and possibly Nicaragua. In contrast, A. asignum was found in the Guanacaste and Central Cordilleras of Costa Rica, and A. colorata in the Talamanca Cordillera of Costa Rica and Panama. Acronyctodes cautama is thus far only known from Mexico, west of the Isthmus of Tehuantepec.

The female genitalia of A. corrugata ( Fig. 22 View FIGURES 21–24 ) are immediately diagnostic among the known members of the Cautama-group. The corpus bursae bears a spinate signum, and the posterior half is strongly sclerotized with deep longitudinal corrugations. In contrast, females of A. asignum have an entirely membranous corpus bursae and lack a signum, while females of A. colorata and A. cautama , although possessing a signum and a sclerotized posterior half of the corpus bursae, lack the deep longitudinal corrugations.

The male genitalia are less distinctive and necessitate caution in identification. However, there appear to be notable differences in the arrangement and number of cornuti among species of the Cautama-group. Acronyctodes corrugata has 10–15 cornuti in a mostly linear cluster, A. cautama has 7–10 in a linear cluster, and A. asignum typically has 12–15 cornuti arranged in a mostly linear cluster. In contrast, A. colorata usually has 30–35 cornuti in a dense non-linear cluster, and A. bisbili has approximately 25–30 cornuti in a dense non-linear cluster.Additionally, the apex of the valve in A. asignum , A. corrugata , and A. cautama is slightly angulated, whereas in A. bisbili and A. colorata , it appears rounded.

Adult. ( Figure 6 View FIGURES 2–9 ). Forewing length: male: 22–23 mm; female: 25 mm.

Head: Antenna bipectinate in both sexes; rami of male about 3x longer than those of female; scales above ochreous with scattered black scales. Frons and vertex ochreous gray. Labial palpus 1.5x diameter of eye, ochreous gray. Haustellum well-developed.

Thorax: Tan to ochreous gray. Legs tan to ochreous gray, mottled with dark gray to black patches. 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 tan, variable amounts of brown and olive green; smooth antemedial line, modestly dentate postmedial line. Medial area between antemedial and postmedial lines slightly browner. Black discal spot present and post-discal area near discal spot with blackened patch. Subtle, diffused darkened medial line sometimes present near postmedial line. Hindwing grayish-tan with transverse medial black dentate line and black discal spot; discal spot may have additional subtle transverse line through it. Underside of both wings like upperside but with pattern elements more spotty and color highly variable. Fringe sometimes with light checkering.

Abdomen: Pale gray to tan.

Male genitalia: ( Figure 17 View FIGURES 16–20 ). Uncus triangulate and campanulated, ending in hood-like apex. Medial posterior projection of gnathos papillated. Valve broad with costal sclerite ending in subapical acuminate process. Juxta plate-like with large posterior digitate process. Vesica with ca. 10–15 spinose cornuti in a tight linear cluster.

Female genitalia: ( Figure 22 View FIGURES 21–24 ). Posterior apophysis approximately half length of anterior apophysis. Ductus bursae with anterior sclerite. Corpus bursae long and ovate, with highly sclerotized, corrugated posterior half. Signum inwardly directed, cup-like, and bearing numerous spinate projections.

Larva: ( Fig. 28 View FIGURES 25–32 ) Head black with white suture separating frons and lobes; clypeus white. Body white medially, transitioning to yellow through thorax to A1 and through A6-A10. Body with broad dark gray addorsal, supraspiracular, subspiracular, and adventral stripes, each bordered by thin black pinstripes. Spiracular area white medially, with region around black spiracles heavily spotted, exhibiting patchwork of ill-defined black patches.

The larva resembles A. bisbili ( Fig. 27 View FIGURES 25–32 ), although our specimen of the latter shows less pronounced black spotting in the spiracular area. Additional larvae from both species are needed to draw definitive diagnostic conclusions.

Holotype. ♂, MEXICO: Chiapas, San Cristóbal de las Casas, Parque Montetik , (16.682°, -92.599°), elev. 2400m, 20-21-VIII-2022, coll. IJ Garzón, TA Matson, FR Joele, & JJ Dombroskie, Genitalia Slide: TAM-2022-169, [ CNIN]. GoogleMaps

Paratypes (3♂, 9♀). 3♂, 1♀, MEXICO: same collection data as holotype except: “Genitalia Slide: TAM-2022- 170 [♀], [ CNIN] . 2♀, EL SALVADOR: Cerro Miramundo, Metapán , 2300 m, 1-4-III-1972, coll. S. & L. Steinhauser, [ USNM] . ♀, EL SALVADOR: Hac. Montecristo, Miramundo , 2300 m, 13-XI-1971, [ USNM] . ♀, EL SALVADOR: Cerro Miramundo , 2300 m, 23-I-1971, [ USNM] . ♀, MEXICO: Chiapas, El Colegio de la Frontera Sur (ECOSUR) , (16.7063°, -92.6161°), 2127 m, Larva: 29-VIII-2024, Lot: A#1, Host: Buddleja cordata, Pupation : 19-IX-2024, Eclosion: 15-X-2024, Andrea Murillo-Vázquez, [ ECOSUR] GoogleMaps . ♀, MEXICO: Chiapas, El Colegio de la Frontera Sur (ECOSUR) , (16.7063°, -92.6161°), 2127 m, Larva: 07-IX-2024, Lot: A#4, Host: Buddleja cordata, Pupation : 20- IX-2024, Eclosion: 19-X-2024, Andrea Murillo-Vázquez, [ ECOSUR] GoogleMaps . ♀, MEXICO: Chiapas, El Colegio de la Frontera Sur (ECOSUR) , (16.7063°, -92.6161°), 2127 m, Larva: 07-IX-2024, Lot: A#5, Host: Buddleja cordata, Pupation : 20-IX-2024, Eclosion: 21-X-2024, Genitalia slide: TAM-2024-507, Andrea Murillo-Vázquez, [ ECOSUR] GoogleMaps . ♀, MEXICO: Chiapas, El Colegio de la Frontera Sur (ECOSUR) , (16.7063°, -92.6161°), 2127 m, Larva: 13-IX-2024, Lot: A#6, Host: Buddleja cordata, Pupation : 19-IX-2024, Eclosion: 15-X-2024, Andrea Murillo-Vázquez, [ ECOSUR] GoogleMaps .

Distribution. ( Fig. 36 View FIGURES 33–36 ). Acronyctodes corrugata inhabits the Central American montane and pine-oak forests from southern Mexico (Chiapas) through El Salvador and Honduras, and likely into Nicaragua.

Biology. ( Fig. 28 View FIGURES 25–32 ) The immature stages and life history of A. corrugata were revealed by author AMV. Larvae were collected from Buddleja cordata near San Cristóbal de las Casas, Chiapas, Mexico. Four adults, now paratypes, were successfully reared from the caterpillars, and these individuals were subsequently identified as A. corrugata through external examination and genitalic dissection by TAM.

The cocoon of A. corrugata is a well-organized white mesh, somewhat resembling the cocoon of A. mexicanaria .

Etymology. The specific epithet corrugata recognizes the sclerotized, corrugated posterior corpus bursae in the female genitalia, distinguishing this species from visually similar known congeners.

Molecular data. Six specimens of A. corrugata ( BOLD BIN: BOLD: AAZ5681 ) have been DNA barcoded, revealing a pairwise distance of approximately 1.9% from nearest-neighbor, A. cautama ( BOLD BIN: BOLD: ACT3853 ) .