Sesiidae
2 species in 2 genera are known from Block Island. Most members of this family are day-flying, resemble wasps or bees, and have large portions of the wings without scales and thus transparent. The family is understudied on Block Island owing to its day-flying habits.
Schreckensteiniidae
1 species is known from Block Island. This family is represented by just three species in one genus in the continental US and Canada. Adults dramatically elevate their hindlegs at rest; this unusual trait is shared with the following taxa in the Nearctic: Stathmopodidae, many Heliozelidae, and the incertae sedis genera Cycloplasis and Cyphacma.
Glyphipterigidae
1 species is known from Block Island. This family of small to tiny moths includes many day-flying species.
Argyresthiidae
5 species in 1 genus are known from Block Island. This family of small to tiny moths includes over 50 species in a single genus in the continental US and Canada.
Yponomeutidae
3 species in 2 genera are known from Block Island. This family of small moths includes mostly white and blue-gray species in the Nearctic region, though some pine feeding species are orange.
Bedelliidae
1 species is known from Block Island. This family is represented by two species in one genus in the continental US and Canada, of which one is widespread from coast to coast and the other is restricted to south Florida.
Carposinidae
1 species is known from Block Island. Moths in this small family superficially resemble many Nolinae. The representatives of this family in eastern North America are small and gray with a distinctive pattern of raised scale tufts.
Blastobasidae
11 species in 5 genera have been recorded on Block Island.
Psychidae
1 species is known from Block Island. Larvae in this family construct cases for protection and camouflage. Adult males of most Nearctic species are either entirely black or bizarre-looking with large clear patches on the wings. Females are often larviform or, if not, with vestigial wings, and they generally mate and lay eggs while still at least partly within their larval cases, leaving only to die.
Batrachedridae
2 species in 2 genera are known from Block Island. This small family of mostly very small moths is represented in the continental US and Canada by four genera, with the type genus containing the bulk of the species.