The most common plant pests

The tiny little insects seem to be omnipresent in the hobby garden and are not afraid to enter the house and bother the indoor plants. Only rarely does it remain with a selective infestation. Rather, the parasites trigger a chain reaction in which viruses and fungal spores use the injured cell tissue to gain access to the plant. The leaves curl up, are covered with a black coating and show damage caused by feeding. When the plant pests first appear, consistent countermeasures are required, because the little beasts are capable of procreation, so that they multiply explosively.

• If possible, spray the brood with a sharp jet of water.
• Treat diseased plants regularly with a soft soap and alcohol solution.
• Release beneficial insects such as ladybugs, parasitic wasps or predatory mites.

Spinnmilben (Tetranychidae)

The 0.5 mm small spider mites make life difficult for leisure gardeners all over the world. The pests puncture the leaves, sucking out the sap and significantly weakening the plant. Although they are microscopically small, the trained eye quickly recognizes an infestation, because European mites protect themselves under a white web. Yellowed foliage dotted with yellowish speckles also indicates the parasites. Since spider mites are considered an indicator of severe drought, part of the control involves correcting this deficiency.

• Irrigate garden plants and spray indoor plants.
• Use predatory mites in the greenhouse.
• Keep infested plants cooler in the house and conservatory.

Whitefly, whitefly (Aleyrodoidea)

They are actually pretty to look at, the 1-2 mm small insects with their filigree, mealy-white wings. If it weren’t for her fondness for nutritious plant sap. To get at it, the plant pests pierce the epidermis and suck as much as they can. At the slightest touch, they fly up in swarms. Not only do the adult whitefly damage the plant, but also the larvae that attach themselves to the underside of the leaves. In order to expel the plague from the garden or from the indoor plants, it is not absolutely necessary to use chemical preparations.

• Spray with soft soap solution or ready-made potash soap.
• Catch the insects with sticky traps under glass.
• Use the predatory mite varieties Phytoseiulus persimilis and Amblyseius californicus one after the other.

Weevil (Curculionidae)

In the ranking of the most common plant pests, weevils consistently occupy a top position. Among the 60,000 species known worldwide, there are more than 1,000 that are up to mischief in German home gardens. They don’t even shy away from the tubs and planters on the balcony. The vine weevil is one of the most well-known representatives, closely followed by the gray weevil and the large brown weevil. Luckily, measuring around 20mm, they are easy to spot as they invade the garden. Adult beetles feed on the plants above ground, while the larvae attack the tender roots. The result is wilting, dying plants that can hardly be saved. Hesitant defensive measures are not helpful in the face of this plague.

• Collect the weevils daily in the early morning hours.
• Use nematodes to control the larvae and traps to control the adult beetles.
• Attract natural predators to the garden such as birds, spiders, hedgehogs and centipedes.

Snails (Gastropoda)

By far the greatest damage in the home garden is caused by slugs, especially the Spanish slug. The nocturnal molluscs love a warm, humid climate, where they flock in droves to devour the plants in the garden. However, they are particularly interested in young useful and ornamental plants. With a length of 8 cm to 15 cm and a bright brown to reddish-orange colouration, these plant pests are easy to recognize, which is helpful with various control methods. It is important to note that snails, such as the rare Roman snails, should be protected because they do not cause any damage.

• Collect the snails in the early morning twilight.
• Sprinkle coffee and coffee grounds as a deadly poison.
• Snail collars and snail fences serve as mechanical defense methods.

Apfelwickler (Cydia pomonella)

The gray-brown moth with greyish stripes is 1 cm long and has a copper-colored spot at the end of its wings. In May and June, this butterfly flies out at dusk to scatter its baleful brood on leaves and young apples. It is the white-yellow larvae, up to 2 cm long, that drill into the fruit on apple trees and nest in it. Depending on the weather, the resulting crop failures are catastrophic, because the maggots multiply explosively at temperatures above 15° Celsius. Home gardeners who grow the fruit for consumption will avoid chemical insecticides.

• From January, shake the apple trees regularly and collect the fallen pupae.
• Apply caterpillar glue rings to each vulnerable tree in early spring.
• Prevent mating by means of attractant traps and the confusion method.

Box tree moth (Cydalima perspectalis)

The small Asian butterfly enchants with silky, white wings, as if it could not muddy water. Since 2006 it has been attacking box trees as an incredibly destructive pest. The level of knowledge regarding the way of life and the most effective control is still in its infancy. It has been proven that the adult box tree moths live only a few days and do not eat during this time, in contrast to the larvae. These eat a box tree bare from the inside and at the same time surround it with a dense web. From spring to autumn, 2 to 3 generations develop, which have meanwhile caused a considerable decline in the boxwood population. The earlier an infestation is detected, the better the chances of getting rid of the plant pests.

• From March, examine the boxwood for light spots and webs.
• At the first sign of an infestation, cut back the plant vigorously.
• As a final solution, spray spray with thiacloprid under high pressure.

Kartoffelkäfer (Leptinotarsa decemlineata)

A plant pest with a high destruction factor is the voracious potato beetle. Thanks to its warning colors in the form of dark vertical stripes on a yellow background, it is easy to recognize; Of course, this does not prevent the beetle from devastating a house garden within a short time. The bright red larvae also contribute to the fact that there is hardly anything left for the harvest if the hobby gardener does not counteract the wolverines. In addition to potatoes, aubergines, tobacco, peppers and tomatoes are also on their menu. Since the use of chemical insecticides is out of the question, the control strategy revolves around ecologically compatible methods.

• Collect beetles and larvae from the leaves early in the morning.
• Use selective sprays with Bacillus thuringiensis.
• Cultivate potatoes in mixed culture with peppermint, horseradish, caraway and marigolds.

Rhododendronzikade (Graphocephala fennahi)

They are masters of camouflage, because a colorful pattern protects the rhododendron planthoppers from prying eyes. The widespread plant pests do not want to be observed with their shameful doings on the magnificent flowering bushes as well as on linden, plane and aron. Mottled leaves indicate the sucking activity with which the cicadas weaken a rhododendron to such an extent that the buds die off. At the same time, the parasites infect the plant with the fungal spores that cling to them. The actual extent of the damage is only apparent in the following spring when the flowers do not appear.

• Hang sticky traps and yellow boards in the bushes to catch the adult insects.
• Break off any dead, darkened buds.
• As a spray, preparations with the active ingredient acaricide are currently permitted in the home garden.

Saateule (Agrotis segetum)

The small moth is spreading throughout Europe, inhabiting mountains, valleys, meadows and steppes. Allotment gardeners fear the plant pest because it nibbles at the roots of useful and ornamental plants. The plant pest is difficult to get rid of, because the sowing owl can hardly be identified due to its inconspicuous, brownish colour, especially since it prefers to swarm out at night. A female lays up to 1,500 eggs during her three-week lifetime, from which insatiable larvae hatch. The seed owls are active well into November, so the recreational gardener should keep an eye on the pests throughout the growing season.

• Mark infested plants during the day to collect the caterpillars at night.
• Attract natural predators such as birds, hedgehogs, earwigs, ground beetles and parasitic wasps.
• Use ecologically compatible sprays with the active ingredient Bacillus thuringiensis.

Click beetle (Elateridae)

As with the majority of plant pests, it is not the adult insects of the click beetle family, but rather their larvae that significantly impair the growth of garden plants, even leading to their complete death. The 5 cm long larvae of the click beetle have proven to be particularly resilient because they have relatively hard armor made of chitin. Nevertheless, they can be effectively combated with the help of a few gardening tricks.

• As a trap, fill a ditch with manure, cover it and destroy the trapped worms.
• Lime the soil extensively and surround the beds with marigolds or marigolds.
• Cut open the potatoes, bury them upside down and collect the attracted wireworms.

Wühlmäuse (Arvicolinae)

The most common plant pests do not necessarily all come from the realm of insects and molluscs. Rodents, such as voles, also give the hard-working hobby gardener a headache. Lemmings, muskrats, field mice and water voles also belong to this category. The burrowers, which are up to 20 cm long, have grey-brown to black fur, a short to medium-length tail and small ears. Depending on the genus, they are either diurnal or nocturnal. They gnaw on numerous garden plants such as vegetables, fruit, berries or roses and usually cause considerable damage. Of course, the environmentally conscious hobby gardener does not condemn them to death for this reason, but strives for permanent deterrence.

• Use scents such as lavadin oil, castor oil, elderberry manure, and aged buttermilk.
• Set up live traps according to the manufacturer’s instructions.
• Use loud noises as an acoustic barrier.

Please note: Before taking any action against voles, it is important to make sure that they are not moles. These whimsical mammals are by no means considered plant pests. Solely because of the mounds they cause, moles are not welcome in the home garden. Since the little animals are under nature protection, no hobby gardener should risk a fine of up to 50,000 euros for chasing a mole.

Conclusion
As long as pests occur sporadically in the garden, they are just annoying. Of course, the situation becomes critical when the pests multiply to such an extent that they devastate the lovingly tended ornamental garden or destroy the harvest in the kitchen garden. If the most common plant pests are known, the informed hobby gardener will know in good time how to take targeted action against aphids and the like.