Migration to roots by first-instar nymphs, and not by alates, in the gall aphid Clydesmithia canadensis

animal developmental stages aphididae etapas del desarrollo animal gall causing insects insecte gallicole insectos causantes de agallas larvae larvas larve migration ninfas nymphe nymphs pests of plants plagas de plantas plante ligneuse populus balsamifera populus trichocarpa racine ravageur des plantes roots woody plants