Very small insects with a size of a few millimetres, which represent a suborder of the large group of plant aphids (such as aphids). The females, which are usually wingless in contrast to the males, infest the leaves, fruits and bark of various plants, including vines. They are mainly found in warmer areas, in Central Europe mainly the cup scale aphids (Coccidae). With their piercing-sucking mouthparts with stinging bristles, they feed by piercing plant tissue. This leads to growth disorders, discolouration, wilting and even death. The animals also excrete honeydew, which is often colonised by black soot fungi. The insects develop from the egg through up to five larval stages and a nymph to the sexual animals, which then have the typical protective covering (shield). The species Planococcus and Pseudococcus also transmit viruses that cause leaf roll disease and corky bark disease (see under Rugose Wood-Complex).
Of particular importance for viticulture is the "vine scale insect" (Parthenolecanium corni), also known as the "plum scale insect" or "common plum scale insect". It attacks plums, apricots, gooseberries, currants and also vines. It overwinters as a second larval stage on branches and shoots and also in the soil. With budbreak, the larvae migrate to the young shoots, where they develop into females about six mm in size towards the end of May. At the same time, the back thickens and solidifies into a highly arched, brownish and lacquered shield, under which up to 3,000 eggs are found (hence the name). The larvae hatch towards the end of June, migrate to the underside of the leaf and suck on it. There is usually only one generation. The species "woolly vine scale aphid" (also called "blood aphid" because of salmon red eggs) also attacks the roots. There are also other species such as the grapevine smear a phid. Natural enemies are lacewings, ladybirds and ichneumon wasps, some of which are deliberately released. See also under vine enemies.
Picture left: By Vijay Cavale indiabirds - Own work, CC BY-SA 3.0, link.
Image right: By J.Rzadkowski - Own work, CC BY-SA 3.0, Link
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Markus J. Eser
Weinakademiker und Herausgeber „Der Weinkalender“