In nature, there are no “pests”, because every little animal, no matter how small, fulfills its purpose and is part of the food network. Normally, aphids & co. are kept in check by their natural predators (= “beneficial insects”). Only when a functioning ecosystem is out of balance can overpopulation of a particular species occur. This happens, for example, through the use of insecticides and pesticides, which in fact harm not only the “pests” but also their predators. In the absence of these as a regulatory unit, pests can proliferate en masse and prey on our crops. So beneficial insects can help maintain a healthy balance in the garden and protect our crops.
At a glance
For beneficial insects to thrive in the garden, they need just four things:
- A diverse food supply
- Nesting opportunities
- Cover from enemies
- Protection from the cold season
How do I encourage these useful garden helpers?
No use of toxic pesticides
Diverse native plants (trees, hedges, shrubs and flowering plants)
Diverse small structures (e.g. a pile of dead wood, loosely piled stones, leaves left lying around,..)
Of course, if you want to successfully work with beneficial insects as a gardener, you must first recognize his little helpers. Many of them resemble their harmful relatives and can therefore be easily confused. A certain tolerance for pests is also necessary, because pests are indispensable as a food source for beneficial insects. Beneficial insects would never completely eliminate their food source, and neither should we.
Mostly red, but can be yellow or other colors. Native is the seven-spot ladybug, but the spots can vary in number and size. An adult beetle eats 100-150 aphids daily. The larva can consume 400-800 aphids until pupation. After hibernation, ladybugs are especially hungry and clean up the garden properly. So when the first aphids appear in spring, first be patient and observe whether the ladybugs become active in the garden. The larvae hatch from yellow eggs that are set up vertically. They are dark gray-blue in color and have orange-yellow spots.
Filigree insects with translucent green-blue veined wings and golden eyes. Adult lacewings feed mainly on honeydew and water, but also on aphids and small insects when hungry. The brownish larvae grab aphids, spider mites, scale and blood lice with their pincer-shaped jaws. In winter, the adult lacewings seek sheltered nooks in cool sheds; to avoid disturbing them, the big cleanup can be postponed until spring, when the elf-like insects float back into the open.
They are black and yellow patterned and easily recognized by their fast, silent flight. They can flap their wings so fast that they literally stop in mid-air. Their lightning-fast zigzag movements are also characteristic. The white-yellowish larvae look like maggots and feed on aphids. Hoverflies therefore like to lay their eggs in aphid colonies in spring. Adult hoverflies feed on pollen and honey, playing an important role as pollinators.
Tip: Umbelliferous plants (e.g. dill, chervil, wild carrot) attract hoverflies.
Earwig (ear moth).
These small creepy-crawlies have an unjustified reputation for nesting in human ear canals. At most, they use their pinching tools to deter predators and thus defend their offspring. In the garden they can even be quite helpful, because the nocturnal predators exterminate aphids and other insects. They are particularly popular for protecting fruit trees.
Tip: With the help of flower pots stuffed with wood wool or straw, you can easily provide them with a shelter. These are then hung in the trees in such a way that they still have contact with branches or branch forks, so the earwigs can get in and out more easily. They can then hide in the small burrows during the day and go hunting right on the spot at night.
These insects are much smaller and have a narrower body than their stinging relatives. There are many different species, but they are all completely harmless to humans. ichneumon wasps can be recognized by their characteristic wasp waist and the long laying spine on their abdomen. They use this to “drill” into aphids, for example, and then lay their eggs inside. The larvae eat their host from the inside and then overwinter pupated in the hollow louse. Some species specialize in the spider moth, the caterpillars of the cabbage white butterfly, or the pupae of the onion fly.
Tip: In the garden, look out for the aphid mummies in which the wasps overwinter and preserve them. To do this, simply look closely at infested plants; hollow aphids are easy to distinguish from live ones when you take a closer look. It is best to leave the affected plants undisturbed. Tree prunings and herbaceous growth under shrubs also provide valuable shelter. Umbelliferous plants provide sufficient food.
Bugs in the wild have nothing to do with the dreaded bed bugs. There are many different predatory bugs that feed on pests. They have flat bodies, leathery, sometimes colorful wing covers, and proboscis-shaped sucking and stinging organs. Among the most important beneficial insects are flower bugs and soft bugs. They eat spider mites, aphids, and smaller caterpillars.
There are countless species, including the golden ground beetle and the pupa robber. They can be identified by their metallic green-gold and bronze wings and their long, strong legs. Ground beetles and their larvae are among the larger predators and go after slugs(eggs), Colorado potato beetle(larvae), wireworms, pupae, caterpillars, aphids, and mites at night. Damp places under leaves, wood or stones serve them as shelter.
Predatory mites are arachnids, grow only about 0.5 mm in size and sit on the underside of leaves. They are reminiscent of their harmful relatives, the spider mites. Unlike the latter, however, they do not produce a web, so they can be easily distinguished. The predatory mite Phytoseiulus persimilis is specially bred for biological pest control to get the red spider mite (= fruit tree spider mite) under control.
There is a huge variety in the realm of spiders: cross spiders, jumping spiders, wolf spiders – the list is long. Some build webs, others live on the ground, and they also differ greatly in size and shape. However, they all have in common the eight legs. With many they are rather unpopular because of their appearance, but in the garden they are always welcome. Indeed, spiders are among the most successful pest hunters! They catch flies, moths, beetles, caterpillars, bugs and aphids. Ground cover plants, wild herbs and natural stone walls provide them with a habitat.
Insectivores possess a flying skin stretched between the trunk and limbs. They are nocturnal and have excellent ultrasonic orientation in the dark. They spend the cold season in hibernation hanging upside down from the ceiling. As beneficial insects, they eat nocturnal moths such as fruit tree moths, owl butterflies, peepers and gnats. The most effective way to protect bats is to provide them with hiding places in open attics or tree cavities and then leave them alone.
These spiny four-legged creatures are among the more congenial of the beneficial insects. Their offspring are usually born in spring. The hedgehog family then stays together until autumn and goes hunting together at dusk. Hedgehogs spend the winter curled up in an undisturbed nest. Their metabolism is reduced to a minimum, breathing only two to three times a minute. They feed on snails, grubs, worms, caterpillars, mice and even snakes. However, they are not averse to strawberries and apples. To protect them, you can simply leave an undisturbed corner under bushes, where leaves and bush cuttings are left. There the hedgehogs can build a nest and survive the cold winter.
Have a velvety black-grey coat and can grow up to 17cm long including the tail. Characteristic are their shovel-like digging paws, the long snout and the small, button-like eyes. Their digging activities make them unpopular with many gardeners, but they can also be useful to us. These industrious insect hunters eat mole crickets, larvae, pupae, grubs, slugs and even the nests of voles. They have to eat as much food as they weigh themselves every day! Once a bed is spoiled by molehills, the soil is excellent for flower pots, because it is loose and “pest-free”. The rest is simply raked smooth again.
Are easily recognized by their pointed snout, short tail, and an unpleasant musky odor. Their backs are gray-brown in color, but their bellies are lighter. They do not eat plants and do not do any other gnawing damage. Snails, insects, mole crickets and larvae are at the top of their menu. Every night they have to eat their own body weight, so they are very active as beneficial insects. They like to take shelter under stones, piles of leaves, in bushes or in a hollow tree stump. Provide such undisturbed places in the garden, so that the mice can protect themselves from cats and other enemies.
Many caterpillars, grubs, larvae and aphids are needed, especially when raising young. Native hedges and shrubs provide roosting and nesting opportunities for birds. In addition, nesting boxes for birds can be built yourself. Care should be taken to use only untreated wood and to leave the inside of the box rough as a saw, so that the young birds have an easier time leaving the cavity later. In addition, the boxes should not be painted with artificial colors, but only glazed with natural means weatherproof. Please also remember to leave an opening, the nesting boxes should be cleaned in the fall, so that no diseases can settle. The entrance hole should not face the weather side (west), nor should the box be exposed to the blazing sun for too long (south). An orientation to the east or southeast is therefore ideal. When placing the box, a quiet and cat-proof location should be chosen. In harsh winters, a feeding station should be set up in the garden.
Are not snakes, but belong to the lizards. Their snake-like body is gray-brown to copper and black striped on the back, the abdomen is darker. They love damp meadows and garden corners where they feed on worms, insects and slugs. For protection, undisturbed corners can be left by the compost and under modernizing wood. They should also be kept away from curious pets.
Common toads, grass frogs, pond frogs
Common toads are brown in color and covered with warts; their eyes are large and golden. Grass frogs have a dark brown spotted back, the belly appears lighter. The pond frog is greenish in color, characterized by the sound bubbles that it inflates like balloons to croak. Toads and frogs need a watering place. Suitable conditions for them can be created with the help of ponds and wetlands. Dense, moist riparian vegetation serves as optimal protection for them. Their favorite food includes slugs, worms, isopods and other insects.
Encourage beneficial insects in the garden
A wealth of different plants and structures creates valuable habitats for a variety of insects, birds and mammals. Creating this wealth of structure in the garden couldn’t be easier. Many things that most people would normally dispose of can still be useful to native wildlife:
- A pile of dead wood
- Loosely piled stones
- Leaves left lying around (or piled up into heaps).
Different trees, hedges, shrubs and flowering plants also provide new niches and food sources for beneficial garden inhabitants.
Those who enjoy craftsmanship can additionally build artificial nesting aids. A classic nesting aid for wild bees is, for example, drilled hardwood discs made of oak or beech (no coniferous wood!). The drill holes should have a diameter of 2-8 mm. Reeds or woody stems of perennials and shrubs also provide a welcome nursery for wild bees. The stems can simply be tied together in a bundle or stuffed into a tin can. Then simply attach the nesting aids to a sunny, rain-protected wall with the opening facing forward – done! Soon the little pollinators will be nesting in their new home.
Unfortunately, as beautiful as homemade nest boxes are, they only support a fraction of the existing diversity of wild bees. Most species actually breed underground and can do little with an insect hotel. They are helped, for example, by preserving free (sand) areas in the garden that are not disturbed too much.
Hopefully, we were able to illustrate with this article how important the most diverse beneficial insects are for the ecological balance in the garden. With a little patience, toxic pesticides can thus be dispensed with, because as Goethe already recognized: “In nature there is an eternal ebb and flow of beneficial insects and pests. Just let them all, then the one eats up the other”.