A good example of a fairly typical case is afforded by Heterodera schachtii, which attacks beetroot and causes great loss to the Continental sugar manufacturers.
A, Male Heterodera schachtii, greatly magnified.
Ear-cockle of wheat; Cephalobus rigidus (Schn.), on oats; Heterodera radicicola (Greef), on the roots of tomatoes, cucumbers, potatoes, turnips, peach-trees, vines and lettuce, and many other plants.
A,a,Female Heterodera schachtii Schmidt, breaking through the epidermis of a root; the head is still embedded in the parenchyma of the root.