Abstract
Thirty species of the genusLygocorisReuter known to occur in Canada and Alaska are reviewed.Lygocoris confusus(Knight) is considered to be a synonym ofL.contaminatus(Fallen),communisvar.novascotiensis(Knight) is a synonym ofcommunis(Knight),caryaevar.subfuscus(Knight) is a synonym ofcaryae(Knight), andcanadensisvar.binotatus(Knight) is a synonym ofcanadensis(Knight). The species considered are:pabulinus(Linnaeus),lucorum(Meyer),alni(Knight),artricallusKelton,atritylus(Knight),belfragii(Reuter),canadensis(Knight),caryae(Knight),clavigenitalis(Knight),communis(Knight),contaminatus(Fallen),fagi(Knight),geneseensis(Knight),hirticulus(Van Duzee),inconspicuus(Knight),invitus(Say),johnsoni(Knight),knightiKelton,laureae(Knight),omnivagus(Knight),ostryae(Knight),parrotti(Knight),piceicolaKelton,quercalbae(Knight),semivittatus(Knight),tiliae(Knight),univittatus(Knight),viburni(Knight),vilticollis(Reuter), andwalleyiKelton.A key to species, brief redescriptions, illustrations of species and male claspers, distribution maps, and host plants are included. A list of the remaining 10 species known from the United States is appended.