A new subspecies of Cigaritis (Spindasis) vulcanus Fabricius, 1775, Cigaritis (Spindasis) vulcanus sulawesiana ssp. nov., is described from the main island of Sulawesi, Indonesia. It is smallest in the genus Cigaritis and has a characteristic teardrop-shaped band from the base to discal in space 1b of the hindwing underside. The wing markings and male genitalia distinguish it from other subspecies of vulcanus. This is the first record of this genus from Sulawesi mainland.

Adult males emerge earlier than females in a number of insect species, a phenomenon known as a type of protandry. To clarify whether protandry is an adaptive trait or a byproduct caused by differences in developmental time between males and females, I investigated the developmental pathways of two lycaenid butterflies, Chrysozephyrus smaragdinus and Iratsume orsedice. The larvae of these species overwinter in eggshells, and hatch in the spring when their host plants undergo budding. Therefore, earlier hatching of males than females would support protandry as an adaptive trait. In addition, the mating systems of these butterflies would provide insights into the evolution of protandry. C. smaragdinus is a perching species, and males arriving at perching sites early in the adult season tend to continue occupying the site after interactions with intruding males. Consequently, males should emerge earlier than not only females but also other males. In contrast, I. orsedice is a patrolling species in which males may have to emerge earlier than females but need not emerge earlier than other conspecific males. Therefore, the degree of protandry would be greater in C. smaragdinus than in I. orsedice. I reared the butterflies in the laboratory, and found that male larvae hatched earlier than female larvae, indicating that protandry is an adaptive trait in these species. I also found that the degree of protandry was greater in C. smaragdinus than in I. orsedice, consistent with the notion that males should emerge earlier in perching species than in patrolling species.

Thecobathra heppneri Sohn, 2018 is recorded for the first time from Japan. The figures of habitus and female genitalia of the species are provided in addition to the sequence of the mtDNA COI barcode region.

A butterfly species, Purple Emperor, Apatura iris (Linnaeus, 1758), is recorded in Mongolia for the first time. The specimens of two males and three females of this species were collected from the forest steppe in the mountainous area of Sharyngol, Darkhan-Uul Province, Mongolia. On both sides of the dirt road through this forest steppe, there was an abundance of willow trees (Salix spp.), which provided a suitable habitat for this species. The specimens we collected are believed to be A. iris amurensis Stichel, 1908. Sharyngol is located about 300 km south of Lake Baikal, and the forest steppes extend from the southern tip of the Republic of Buryatia and the southern tip of the Zabaikalsky Krai eastward across the border into Mongolia. It is possible that the distribution of this species has extended through these regions to Sharyngol.

Coleophora limoniella Stainton, 1884 is newly recorded from Japan. The female adult specimen and genitalia are illustrated.

Head capsule widths of Curetis acuta paracura larvae collected in Tokyo (Hachioji) and Ibaraki (Tsukuba), Central Japan, were measured. The butterfly passes through four larval instar stages before pupation. The mean head capsule width of the first, second, third and fourth (final) instar larvae were 0.346, 0.574, 0.952, and 1.834 mm, respectively.

Eupoecilia kobeana Razowski, 1968 is newly recorded from Tanegashima Island and the Yaeyama Islands (Ishigakijima Island, Iriomotejima Island, and Yonagunijima Island). Larvae were discovered in flower buds of Ligustrum japonicum (Oleaceae), Ligustrum lucidum Aiton (Oleaceae), and Vaccinium bracteatum (Ericaceae), representing new host records. Geographical differences in morphology and DNA barcode sequences between populations on Yaeyama Islands and other areas are discussed.

A pyraustine Ostrinia sanguinealis (Warren), which has been known only in Kyushu, is discovered in Kyoto City, Honshu, Japan, for the first time. The female genitalia are drawn based on specimens collected in Kyoto, with the male genitalia obtained in the same place. The larva of this species feeds on Saururus chinensis (Saururaceae), boring inside the plant stalk. This is the first host record of this species and the association with Saururaceae is also first for the genus Ostrinia. The larval morphology and biology of O. sanguinealis are given. DNA sequences of the mitochondrial COI barcode region and nuclear histone 3 of O. sanguinealis are examined for comparison with those of the other Ostrinia species, and the inferred tree placed O. sanguinealis as the sister of the “O. nubilatis species group”. The sudden appearance of this species in the center of Kyoto city is discussed.