Mass occurrence of the autumnal moth Epirrita autumnata Bkh., causes and consequences

betula pubescens betula tortuosa ciclo vital damage defence mechanisms dynamique des populations enemigos naturales ennemi naturel feuille finches finland finlande finlandia histoire historia history hojas insecte nuisible larvae larvas larve leaves life cycle mecanismos de defensa natural enemies noruega norway operophtera brumata pest insects pests of plants pinson plagas de plantas population dynamics ravageur des plantes subalpine forests vaccinium