We describe a new autumnal caddisfly species Chaetopteryx bucari sp. n. from 8 localities in the Banovina region of Croatia. We also present molecular, taxonomic and ecological notes (emergence, sex ratio and seasonal dynamics) on the new species and discuss the distribution of Chaetopteryx species in general and the Chaetopteryx rugulosa group in particular. Based on Bayesian phylogenetic analysis Chaetopteryx rugulosa schmidi was separated from the clade containing the other subspecies of Chaetopteryx rugulosa. Thus the subspecies Chaetopteryx rugulosa schmidi is here raised to species level, Chaetopteryx schmidi, as it was described originally. We further present distribution data on rare species in the genus Chaetopteryx in Croatia.