Brown scale (Parthenolecanium corni) insects on the stem of a greenhouse-grown grapevine (Vitis vinifera).Three scales are attached to the stem; the largest is about 8mm long. Each scale comprises a hard shell, within which is a mature female insect. The female builds the shell when she settles to feed on the sap of the plant. Within the scale, she produces a waxy secretion into which she lays batches of up to 2000 eggs. Scale insects are members of the order Hemiptera. Eggs hatch into nymphs, which leave the shelter of the scale and feed on foliage during the summer, returning to overwinter on stems and branches. Scale insects are widespread and difficult to eradicate due to the close adherence of the scale to its substrate, and also to the wax within it. Females reproduce parthenogenetically; males are short lived and rarely seen.