Aphids (Aphidoidea) belong to the plant aphids with 3000 known species, of which about 850 live in Central Europe in many colours and sizes. They all feed on plant sap. Many of them are specialised in very specific plants - for example, the most dangerous species in viticulture - the phylloxera, which only attacks the vine. They also change their appearance during the course of the year, and their life cycle is very complex. The winged aphids are responsible for the spread, the next, unwinged generations are relatively stationary and form dense colonies very quickly. As plant suckers, the animals are equipped with a piercing trunk. The aphids feed by piercing and subsequently sucking juices from leaves and also roots. As a defensive reaction of the plants, bile (growths) are formed on leaves or roots.
Some species release harmful, sugar-containing honeydew (excrement) onto the leaves. If insects do not harvest it, the sugary sap is quickly colonized by sooty dew fungi. These fungi do not damage the plant directly, but can hinder photosynthesis. Affected shoots and leaves often grow crippled and wither away. They are the main carriers of various plant viruses. Natural enemies of aphids are certain species of ants, lacewing, ladybird, predatory bug and ichneumon fly. Honeydew is a popular food source for various insects such as ants, bees and wasps as well as vertebrates that feed on the sweet sap or use it as a supplementary food. Certain species of ants (Formicidae) beg for honeydew, keep aphids like dairy cows and also protect them from predators (trophobiosis)
The picture shows some Asian ladybirds chasing black bean aphids. The video clip (click to view) shows a larva of the ladybird eating or sucking up to 50 aphids a day. See also a complete list of all diseases and pests under vine enemies.