Although the vegetable grows quickly and often doesn't spend more than a month on the bed, radishes are occasionally attacked by pests. These can lead to complete crop failure if you do not take action against an infestation in time.
What pests attack radishes and how do you fight them?
Some common pests of radishes are the cabbage fly, aphids, flea beetles and cutworms. Countermeasures include crop protection nets, water jets against lice, moist conditions for flea beetles and attractants or nematodes against cutworms.
Small cabbage fly
The five to six millimeter large beet fly differs from the house fly not only because of its smaller size, but also because of its strong hair. Their larvae feed into the root tissue until they pupate. If radishes are infected by the cabbage fly, they usually die and have to be disposed of.
This is what you can do to prevent it
Put tight-meshed cultural protection nets over the bed. This will prevent the adult flies from reaching the substrate at the base of the plant to lay their eggs. If the pupae hibernate in the ground, the measure is not effective. Before planting, loosen the soil thoroughly and remove all weeds. This exposes overwintering stages so that they dry out in the air.
Aphids
These plant sap suckers can be found on almost all plants. They colonize leaves and shoots and secrete sticky secretions, which form a breeding ground for sooty fungi. The affected plant parts show yellowish discoloration and wilt if the pests spread unhindered.
How to get rid of lice:
- Rinse aphid colonies with a hard jet of water
- Distribute a mixture of 70 percent water and 30 percent rapeseed oil on the plants
- Inject neem oil in strong dilution to kill insects
- Spray oregano tea to deter aphids
- Sprinkle stone flour over the vegetable plants
Flea beetles
The tiny fleas do not grow larger than three millimeters and can be black, blue, bronze or metallic in color. Their activity is particularly high under dry and warm conditions. Infected radishes show pitting on the leaves, which wilt as the pests spread and suck more intensively.
How to get relief
Keep the substrate evenly moist so that flea beetles find suboptimal living conditions. Hooking the bed regularly also proves to be useful. Overwintering eggs can be rendered harmless by cleaning the area with a gas burner flame.
Cutterworms
The brown to gray colored owl butterflies lay their eggs on the substrate so that their larvae find suitable food sources. They eat the roots and occasionally above-ground plant parts of radishes and overwinter in the ground. Infected plants show stagnant growth or become stunted if the infestation is widespread.
What helps against it
If you come across cutworms while pulling weeds, you should collect them. An attractant is helpful so that the pests that live deeper in the ground come to the surface. Make a mixture of bran, sugar, ground bitterwood and water and spread the mixture over the bed. Treatment with SC nematodes kills even the last insect pests.
