Hosts alternate between
elm leaves and roots of
grasses and
cereals. The fundatrix (founding or stem mother) lays eggs in a
leaf of the primary host, which are trees in the
genus Ulmus. This stimulates production of
galls where offspring of the fundatrix develop by feeding on host
sap. These mature into winged adult
alates, which complete the life cycle on the secondary host. The species is thought to have originated in
Asia, but now has spread to southern and south-east
Europe and the United States. == References ==