MOTHS OF THESEMIOTHISA SIGNARIACOMPLEX (LEPIDOPTERA: GEOMETRIDAE)

Abstract

Thesignariagroup of the genusSemiothisais a complex of 10 extremely similar species, most of which are host-specific on certain genera of coniferous trees An eleventh species,S.sexmaculata, is also treated in this revision because of its close resemblance to members of thesignariacomplex, although its true affinity appears to be with theliturata–bisignatagroup. The species are described and illustrated, and their synonymy, distribution, variation and biology are discussed in detail, including an account of industrial melanism in a population ofS.pinistrobata. Two new species names are proposed, and eight lectotypes designated. The main center of distribution is northeastern North America, and all of the known species exceptS.fuscariaoccur on this continent. The one Holarctic species,S.signaria, which is generally the commonest in collections, also has the widest range of host plants, feeding on at least six genera of coniferous trees.