Swiss chard is a popular vegetable plant for the home garden. Pests are rarely found on the plants. They usually appear when corresponding intermediate hosts grow in the vicinity. One species requires special attention, although it is not yet widespread.
The black beet aphid prefers to attack Swiss chard
beet fly
In early summer, after an infestation, light to silver-grey patches with an irregular shape appear. They expand progressively over the leaf surface and eventually turn brown. The larvae leave burrows in the leaf tissue. Remove infested leaves in good time so that the maggots do not cause any further damage. If you want to preserve the leaf mass, you can crush the insect pests in their burrows between your thumb and forefinger.
Black beet aphid
Also known as the bean aphid, it uses viburnum and euonymus as its winter roosts. In June, winged generations colonize herbaceous plants and vegetable crops. During the autumn months they leave the plants to lay eggs on winter hosts. Curled leaves are a typical sign of a pest infestation. On the underside of the leaves you can discover larger accumulations of the plant sap suckers. Their sticky excretions are a breeding ground for fungus.
How to fight aphids
Encourage natural enemies such as lacewings, parasitic wasps (€22.99) and ladybugs. They feel comfortable in species-rich vegetation strips with diverse structures. Rinse the colonies off the leaves with a strong jet of water. Treatments with soap solution have a decimating effect on the populations. Manure from tansy and stinging nettles are both a deterrent for the harmful insects and strengthen the leaf tissue. Plant nasturtiums, because these plants serve as catch plants and reduce the infestation of the chard.
Japanese beetle
The distribution status of this species has so far been classified as insignificant. There are experiments that show that the beetle can cause major damage to crops such as Swiss chard. It belongs to the scarab beetles.
Its grubs live in the substrate, where they feed on the roots of grasses and herbs. After pupating, adult beetles hatch between May and June. Their flight time extends into August. They feed on leaf tissue and provide the typical skeleton feeding.
Important identification features:
- copper-colored elytra have a metallic sheen
- Head shimmers golden green
- White tufts of hair are conspicuous on both sides of the abdomen
What helps against grubs?
Mechanical tillage, which takes place in autumn, creates suboptimal conditions. Irrigating lawns during the main flight season promotes egg laying. Don't cut the lawn too deep. The tall grass is unattractive to females, who prefer the easily accessible substrate as a place to lay their eggs. Parasitic nematodes fight the maggots in the soil, although these must be tailored to the species in question.
tips
If you discover larvae in the soil, you should identify the species. A spread of the Japanese beetle, of which isolated finds are known in Bavaria and North Rhine-Westphalia, should be avoided and the plant protection service should be informed.