Last updated on October 23rd, 2023 at 08:29 pm
Ladybugs are popular and considered lucky charms. In fact, they bring good luck, especially in the garden. In spring, when aphids multiply at breakneck speed, ladybugs are often the first to take on the pests. One ladybug larvae will consume hundreds of aphids until they pupate. It’s worth attracting these beneficial garden inhabitants with flowering native plants early in the spring. This way, the females are in the starting blocks for laying eggs when the first aphids appear.
Hardly any beetle family arouses as much sympathy among us humans as the ladybugs. We value them as beneficial insects because most species, as larvae and as beetles, exterminate dozens of aphids or scale insects a day. Individual species of ladybugs eat leaves, and a particular specialist gnaws fungal turf from powdery mildew. However, the most common in our gardens are the two-spotted, seven-spotted, and Asian lady beetles, all aphid hunters.
Aphids on plants are a nuisance to all gardeners. The leaf suckers reproduce at breakneck speed and are pampered and defended by ants because of their sweet secretions. All the nicer to know that aphids are also just part of the food chain in the garden and have numerous predators. Both the ladybug larva and the adult beetle prefer to feed on the pesky, sticky pests, helping to keep aphid colonies under control in a biological and natural way.
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Which ladybug has the most spots?
There is not simply THE ladybug, but around 100 different species in Central Europe and more than 6000 species spread across the globe. Typical for many ladybugs are dots on their mating wings. Some even proudly carry their number of dots in their name: from the humble two-dot to the famous seven-dot ladybug to the 22-dot. Those who think they can count the dots on the beetles’ backs and know the score, however, are mistaken. The two-spot, for example, is only found in winter as a red beetle with two black dots. In summer, it is more often found in black with two to four red spots. The Asian lady beetle also knows color variations, whose basic color varies from light yellow to orange to red. Its often 19 spots can become so large that the base color appears black with a few reddish spots. Others lack the spots altogether and are simply red.
How ladybugs regulate aphids in spring
When aphid populations literally explode in spring, ladybugs quickly get into gear. After a long winter spent hiding in cracks, the first thing the beetles need is plenty of food. The early bloomers with their nutritious pollen are just the thing. If a beetle already meets the first aphids, it also likes to eat them.
Boosted by the protein-rich food, eggs quickly mature in the female. The elongated-oval, yellow eggs are deposited in clutches of about 10-30 eggs on the underside of the leaf directly next to the aphids. Newly hatched ladybug larvae stagger blindly toward the world. How fortunate that they do not have to crawl far until they accidentally collide with an aphid. The louse is immediately pierced and sucked out with relish. Feeding larvae help their siblings find food by emitting an attractant scent that points the way to the aphids.
From zero to a hundred to a thousand: the reproduction of aphids.
To stay one step ahead of their predators, aphids have developed a fascinating strategy. Instead of laboriously mating and laying eggs, they can clone themselves in the spring. Virgin reproduction or parthenogenesis is the name given to the ability to reproduce without a male. There is also another talent: aphids do not lay eggs, but “give birth” to finished young.
This characteristic is called vivipary. Thanks to virginity and viviparity, an aphid carries young, which in turn have children in their wombs. Or in other words, aphids already carry their granddaughters in their abdomens.
In spring, these little “birthing machines” continuously place genetically identical miniature aphids behind them on the leaf. A female can produce around 100 offspring in three weeks in this way. When you consider that such a tiny insect becomes capable of giving birth itself within two weeks, you understand that a few aphids turn into thousands in a short time. Now our ladybug larvae are called upon!
The grandiose drama of being eaten-and-eaten takes place annually in spring, with the weather playing a major role. If the spring is rainy, sap in abundance shoots into the young shoots as the plants sprout. The aphid, which has overwintered as an egg on a twig and now hatches thirstily, unabashedly taps the sap path of the tender shoot.
Due to the rich plant sap, it quickly matures into a fertile female. If a sunny, warm phase follows at this moment, the aphids know no stopping.
The warmth accelerates all vital functions and she produces young at an ever faster pace. In addition, the second generation also begins to reproduce and soon the notorious aphid colonies with several hundred aphids are formed. Through their sucking activity, they can damage the shoots so badly that the leaves curl up. For ladybug larvae, such colonies are a land of milk and honey.
But not every spring holds food in abundance. A cold, dry spring or a change in the weather at the wrong moment can make food scarce for ladybugs. If there are few aphids, the plant is quickly cleaned up. In this situation, the larvae are not afraid to eat their fellow larvae, be they weaker larvae or defenseless eggs.
As soon as the larvae or beetles arrive by mail, remove them from the mailbox
Set out immediately on mild, overcast days
During heavy rain, storms or bright sunshine, store the animals in the refrigerator for the time being, until the weather improves or until dusk
Place adult beetles with a fine brush on the plant next to aphid infestations
Spread the larvae together with the wood shavings in which they are delivered on several pieces of damp household paper.
Clamp household paper, slightly crumpled, as close as possible to the infested shoots in a leaf axil (so that the hungry larvae do not have to search long to find aphids)
Protect ladybug larvae from ants with an ant barrier made of painter’s tape and insect glue (on fruit trees) or, on multi-shoot plants (roses), with diatomaceous earth on the ground around the shoots
Be careful with pesticides and ladybugs
If you discover the aphid infestation late, when the leaves are already curling and the shoots are deformed, you must fear that the plants will be damaged. Now a first aid program is called for. With officially approved biological pesticides, the aphids can be quickly decimated somewhat. However, the agents are also problematic for the ladybug larvae in direct contact. Therefore, they should only be applied if no beneficial insects are sighted on the plant and in any case before applying beneficial insects. Since biological pesticides do not leave toxic residues, you may release the ladybug larvae as soon as the plant is completely dry. Now the ladybug larvae clean up after the aphids to their heart’s content. In doing so, they pursue their prey into hiding places that cannot be reached when spraying.
What is the ladybug’s favorite flower in your garden? And on which plants does it help you in the fight against aphids?