Why do ladybugs eat aphids


General information about the ladybug

As soon as the sun provides more power for warm days in spring, the first ladybugs emerge from cracks in the wall, under bark scales, the litter and under piles of leaves. There the pretty beetles spent the cold season mostly in the company of their conspecifics in a freezing cold and, as the first animal heralds of spring, ensure that we are in a good mood again.

The little beetle has friends all over the world who believe that it has certain magical abilities. It is considered to be the heavenly messenger of the Mother of God, hence the ladybug got its name. In French it is also called God's beast (Bête à bon Dieu). He is supposed to protect the children. That's why they like to send a wish to heaven when it falls on their hands.

He also has a fixed role in popular parlance. In the country, for example, there is a belief that there will be rain if the ladybug flies on your finger and stays there. If he floats away, nice weather should come. In addition, it should reveal the future to impatient women: Put it on your finger and count the seconds until departure, every second should correspond to a year until your wedding.

Ladybirds as beneficial insects in the garden

Ladybugs are important beneficial insects in the garden. Freshly woken up from hibernation, the little crawlers first have to do something about their cravings. Her favorite food is the undisputed aphid. A single one of our native ladybirds eats an average of 50 specimens of the annoying sap suckers per day and is therefore mainly found on heavily infested plants. This is where the females prefer to lay their eggs in spring, from which the larvae hatch a short time later. The hungry ladybird offspring has made a name for itself as the "aphid lion", because a larva will eat no less than 400 to 600 lice by the time they pupate. The offspring of a single beetle can destroy over 100,000 pests per season.

In their hunt for aphids, the ladybirds also have to assert themselves against their protectors. Aphids are cherished and cared for by ants because they collect the lice's sweet excrement as food. If a ladybird or its larva approaches, the ants take rigorous action against it. In turn, it defends itself with a strong-smelling secretion and is also not easily driven away by its prey.

Life cycle of the ladybug

The ladybird year begins in late winter when the insects start looking for partners after hibernating. After mating, the female prefers to lay eggs on plants near aphid colonies. The hatched larvae look different depending on the species and should not be removed as supposed pests, because they devour vast numbers of aphids. After their last moult, they transform into a pupa that usually rests on the top of leaves. The adult, still completely creamy yellow beetle hatches after four to five days. The typical pattern emerges only after the elytra has hardened. Most species overwinter once as adult beetles, some twice, and thus live up to two years.

This is how you can recognize the different types of ladybirds

The Asian species in particular stand out from our native species because of their different colors. But even within a species, the color nuances vary depending on its origin and climatic conditions. In our gallery we introduce you to six different species of ladybirds:

Use in biological crop protection

The number of pests exterminated by ladybirds is so high that these cravings are used in biological pest management. The Asian ladybug was introduced to us as a pest eater a few years ago because it eats five times as much aphids as native species. The newcomer, also known as "Harlequin" because of its variable appearance, is sometimes found in mass populations and in some places even more often than our most common native species, the seven-spotted ladybird. However, the introduction of these beetles is not entirely undisputed. Many animal rights activists fear that the foreign beetles will displace our native species. In any case, it has been proven that the beetles also attack the eggs and larvae of other beneficial insects when the pests dwindle. Incidentally, the number of black dots does not indicate the age of the beetle, but rather the respective species.

Beetle invasion in autumn

As soon as the first cool nights set in in autumn, there are surprising masses of ladybirds in some places. The reason for this is that they gather in large groups for the winter. All kinds of places that are visible and invisible to us come into question as hiding places. You can often see them on window sills, roller shutter boxes, in the garden shed, piles of wood, but also in apartments, hallways, etc. If you prefer to have the beetles outside, you can simply set up a shelter for them in the open air: piles of leaves, moldy tree stumps, piles of wood or specially made ladybird houses offer beneficial insects good protection from the cold.

If the little crawlers still come into the house, they can be prevented from entering with insect protection nets on the windows. Keep the windows closed as often as possible until the first severe frost. If there is an extremely high number of ladybugs, seal the door and window gaps as well as ventilation slots with adhesive tape. If the animals have already entered the house and are spreading uncomfortably, the easiest way to remove the ladybugs is with a vacuum cleaner set to the lowest setting. The dust bag can then be poured out far away from the house. In any case, let the beneficial insects live and never use chemical pesticides!