Morphology of the abdominal regions of Strymonina pupal exuviae (Lepidoptera: Lycaenidae)

Several morphological structures useful for taxonomy have been identified and described in the immature stages of Lepidoptera. In Lycaenidae, the integument of larvae and pupae has received particular attention because it bears specialized organs and setae involved in interactions with ants. However, significant gaps remain in the descriptions of immature stages for many species, especially regarding these specialized structures. Here, scanning electron microscopy (SEM) images of pupal exuviae are presented, including descriptions of dendritic setae and other setal types, the pore cupola organs (PCOs), and the stridulatory region on the abdomen of five Strymonina Tutt, 1907 genera: Arawacus Kaye, 1904; Panthiades Hübner, 1819; Heterosmaitia Clench, 1964; Strymon Hübner, 1818; and Thereus Hübner, 1819. Seven pupal exuviae from six species were examined, focusing on abdominal segments A1–A6. Different types of setae were recorded on the abdominal integument. All specimens exhibit a consistent pattern of setae surrounding spiracles A2–A5, which remain stable within each species. In contrast, the setae surrounding spiracle A6 were dendritic and varied among species. Of the two types of PCOs observed, both are present only in Strymon bubastus (Stoll, 1780). The pupal exuviae structures described here enhance the understanding of pupal morphology and suggest that Arawacus ellida (Hewitson, 1867), Panthiades hebraeus (Hewitson, 1867), Heterosmaitia marius (Lucas, 1857), S. bubastus , Strymon mulucha (Hewitson, 1867), and Thereus ortalus (Godman and Salvin, 1887) exhibit myrmecophily during the pupal stage. This study demonstrates that pupal exuviae are a promising material to access the morphology of immature Lepidoptera.