The genus Acronyctodes Edwards is reexamined following caterpillar rearing and natural history observations, examination of genitalia, and DNA (COI) barcode analyses. Adults, caterpillars, and genitalia of known Mexican Acronyctodes are described and illustrated, and detailed distribution maps primarily derived from iNaturalist data are presented. Acronyctodes eximia (Hoffman & Vázquez) syn. n. is synonymized with A. cautama (Schaus), following a thorough examination of adult morphology, life history data, and DNA barcode analyses. The analysis of 128 COI barcodes, 18 of these representing unique haplotypes from five of the six described species, reveals that three can be reliably distinguished with this fragment. DNA barcodes support two species groups previously suggested by morphology: A. leonilaria + A. mexicanaria and A. cautama + A. colorata. New host plant records demonstrate Acronyctodes species are oligophagous and the study of distributional records reveal A. mexicanaria is sympatric to both A. cautama and A. leonilaria in parts of their ranges.

The immature stages of Mesophleps albilinella (Park, 1990) (Lepidoptera: Gelechiidae) are described herein. Host records for this species were unknown until larvae were collected feeding on seeds within seed capsules of downy rose myrtle, Rhodomyrtus tomentosa (Aiton) Hassk. (Myrtaceae) in Hong Kong, China. Collection sites in Hong Kong are superimposed on a country map and are listed in tabular format. A photograph of a containment cage, used for feeding, mating, and oviposition is provided. Images and scanning electron micrographs of the egg and larva are supplemented with chaetotaxal maps, including the pupa. A laboratory culture of M. albilinella facilitated the description of all immature life stages. Though M. albilinella was collected as a potential biological control agent against R. tomentosa in Florida, it was abandoned due to lack of host specificity during initial host range tests.

Myrmecophytes of the genus Macaranga (Euphorbiaceae) have symbiotic relationships with specific ant species in which ants protect the host plant from herbivores. The intensity of such anti-herbivore defenses elicited by symbiotic ants has been shown to decline with the increase in tree size during tree growth and drastically decrease with various types of disturbances, such as tree falls and ant predation during tree growth. These decreases in anti-herbivore defense during tree growth may cause differences in host plant utilization among leaf-chewing lepidopteran species that vary in the degree of development of myrmecophilous traits. In this study, to test this hypothesis, we determined the interspecific differences in host plant use response to tree size variation and the absence or presence of symbiotic ants among three dominant leaf-chewing lepidopteran species, a myrmecophilous species (Arhopala amphimuta), and two non-myrmecophilous species (Shafferiella macarangae and Aetholix flavibasalis) feeding on a Macaranga myrmecophyte species, M. bancana, in a primary forest in Borneo. The results showed that there were significant differences in the responses to the absence or presence of symbiotic ants and tree size among the three lepidopteran species. The literature has suggested that the larvae of myrmecophilous species prefer trees with symbiotic ants. Although larvae of the non-myrmecophilous S. macarangae were found on trees with and without symbiotic ants, the moth species may prefer trees with weak anti-herbivore defense intensity. We identified another non-myrmecophilous species, A. flavibasalis, that used M. bancana trees as host plants only when symbiotic ants were no longer present on the trees. These results support our hypothesis and suggest that changes in anti-herbivore defense intensity associated with the growth of Macaranga myrmecophytes have a strong influence on host plant usage by lepidopteran leaf chewers.

Four species of Eucosmini are described from western United States: Eucosma owensana, n. sp., Epiblema vargoana, n. sp., Sonia crabtreei, n. sp., and Pelochrista purgatoriana, n. sp. Included is an updated account of Eucosma southamptonensis (Heinrich), with distributional data and an illustration of the previously unknown female genitalia.

A new larval host plant, Selaginella engleri (Selaginellaceae), is recorded for both Ragadia luzonia negrosensis Yamaguchi & Aoki, 1982 and Acrophtalmia yamashitai yamashitai Uémura & Yamaguchi, 1982 from Negros Island, Philippines. The egg and first larval instar are described and illustrated. Other butterflies using Selaginella spike mosses as larval host plants are also listed and discussed.