The genus Hispaniodirphia Lemaire, 1999 is the only genus of silkmoths living on Hispaniola, belonging to subfamily Hemileucinae within the Saturniidae family. There are two species belonging to this genus (Lemaire 1999; Rougerie and Herbin 2006): Hispaniodirphia plana Lemaire, 1999 and Hispaniodirphia lemaireiana Rougerie & Herbin, 2006. Both species are endemic and can be easily distinguished by their wing patterns. Based on current records, H. lemaireiana is not uncommon in the mid-elevation forest habitats (1300–2100 m a.s.l.) of the Sierra de Bahoruco National Park on Hispaniola. However, the female and its earlier developmental stages were unknown until now.

In August 2007, Jean Haxaire and Odile Paquit organized an 18-day entomological field trip to the Dominican Republic, focused on a search for Sphingidae. On August 12^th, they decided to go up from Pedernales to Los Arroyos, along the border with the Republic of Haiti. This track, which was in very poor condition at the time, allowed them to leave the dry coastal biotopes and climb into the Sierra de Bahoruco, a mountain area wooded mainly with Pinus occidentalis Sw. (Fig. 1). This track was not chosen by chance: in 1990, an expedition organized by the Carnegie Museum, bringing together John Rawlins, C. W. Young and S. A. Thomson, collected a fine series of the species Hispaniodirphia lemaireiana there, which was later described by Rougerie and Herbin (2006). The objective was to find this beautiful species.

On the night of the 11^th to the 12^th, a little beyond Los Arroyos, in the direction of El Aguacate, at 1998 m a.s.l., that species arrived almost without interruption from dusk until 3 a.m., demonstrating its strong presence on the site. Since the dominant plant was P. occidentalis, it seemed logical to assume that this was the host plant for this small Saturniidae. On the morning of the 12^th, in less than two hours, about twenty pupae had been dug up, found quite easily at the foot of these trees under less than 10 cm of humus and pine needles. These pupae were given to the care of Daniel Herbin but unfortunately none survived and produced adult moths. The interesting point is that now we knew how to obtain females of this species as they did not seem to be attracted to ultraviolet lamps (or maybe have a diurnal flight). The first author of this note was informed of this discovery and decided to try his luck.

In July 2021, June 2023 and May 2024, Jiri Hodecek and Jiri Pirkl conducted entomological expeditions in the Dominican Republic. The main aims of these expeditions were: i) biodiversity research of chosen groups of insects and their habitat preferences; ii) description of new species; and iii) to provide new faunal records for the Dominican Republic. The expeditions were part of a larger project that focused on different insect groups (selected families of Lepidoptera, Coleoptera, Heteroptera, parasitoid wasps, Diptera, Auchenorrhyncha, Dermaptera and Zoraptera). The project had already brought some results (Sartori 2021; Háva and Hodeček 2023; Hodecek et al. 2024; Lingafelter et al. 2024; Barbosa et al. 2025; De Ketelaere and Hodecek 2025; Háva and Hodeček 2025; Hodecek and Haxaire 2025; Mengual et al. 2025; Laguerre and Hodecek 2026).

Several adults of Hispaniodirphia lemaireiana were caught at light traps in two localities in Sierra de Bahoruco National Park at 1400 and 2000 m a.s.l. during all three expeditions. In June 2023, hundreds of caterpillars were observed across the forest in Sierra de Bahoruco National Park (1407 m a.s.l.; 18°08'15"N, 71°32'38"W) feeding on the endemic pine tree, Pinus occidentalis Sw. (Fig. 2) and dozens of pupae were collected from under the trees. The adult moths were killed with ethyl acetate and stored in paper envelopes; the pupae were collected and brought to Switzerland to finish their developmental cycle, and the caterpillars were photographed with Canon EOS 80D + Sigma 150 mm Macro lens. The successful emergence of the first female encouraged the authors to write this article. In May 2024, a single female was attracted by light (small LED HPL) in Sierra de Bahoruco National Park (2000 m a.s.l.; 18°16'18"N, 71°43'31"W). All photographs in this article were taken with Canon EOS 80D + various lenses (Sigma 150 Macro, Canon 18–55, Canon 50 1.8). Measurements are given in millimetres (mm). Terminology for the larval instars follows Lemaire (2002).

The present observations provide both the first description of adult females and the first ecological insights into the life history of Hispaniodirphia lemaireiana, an endemic saturniid species restricted to the highlands of Hispaniola. Larvae were repeatedly documented feeding on Pinus occidentalis, a pine species endemic to the island and dominant in its high-elevation open forest ecosystems. This host plant association, previously unknown for the genus, suggests a potential evolutionary adaptation to coniferous habitats, which is rare among Hemileucinae, most of which typically utilize broadleaf host plants (but see, e.g., species in the genus Coloradia (Tuskes et al. 1996)).

Last instar larvae exhibit strong crypsis and a heavily armored appearance that is likely an anti-predator adaptation to visually hunting avian predators that are common in montane pine forests. The caterpillars do not seem to form groups as they rest separately lengthwise on pine twigs or trunks during daylight hours.

Unlike other members of subfamily Hemileucinae, whose pupae are often enclosed within silken cocoons, H. lemaireiana undergoes pupation directly in the soil, without any cocoon. Pupae were recovered at depths ranging from surface level to approximately 10 cm underground, particularly in loose, aerated soil under pine litter. This subterranean strategy may aid in desiccation avoidance and thermal buffering in the relatively dry, open pine forest habitat. No evidence of extended diapause was observed in captivity, suggesting a potentially continuous or seasonally flexible development cycle, although further field data are needed to document voltinism.

These findings contribute not only to the morphological characterization of the species but also to a better understanding of its ecological requirements and life cycle, which are essential information for future conservation considerations, especially considering habitat loss and climatic pressures in Hispaniola’s highland ecosystems.

The authors declare no competing interests.