It is annoying when the beautiful flower stands are visited by pests. They indicate an imbalance or suboptimal site conditions. By promoting beneficial insects, harmful insects have fewer chances.
Aphids damage dahlias and transmit disease
aphids
The plant sap suckers are often found on young shoots and flower buds. If the infestation is very extensive, the shoots show stunted growth and the leaves curl up. Not only the lice themselves, but also the secondary diseases make dahlias difficult. The sticky secretions of the pests, known as honeydew, are a breeding ground for sooty mold.
mosaic disease
Dahlia mosaic virus is transmitted by sap-sucking insects such as aphids. A yellow-green spot formation on the leaves is typical, which appears in spring and is reminiscent of a mosaic. The plant suffers from stunted growth and develops stunted plant parts. Since diseased tubers lead to diseased plants, control is only possible by completely removing the affected stocks.
This helps against aphids
Spray the aphid colonies with soapy water or neem oil. Beneficial insects like ladybugs eat aphids. To prevent an infestation, you should cultivate dahlias in a warm and sunny spot. Prevent leaves and flowers from getting wet when watering. Good ventilation of the stocks prevents a humid environment in which the pests feel comfortable.
leaf bugs
These insect pests prefer warm weather, leading a hidden life, making them difficult to spot. The leaves show yellowish sucking points where the bugs have sucked the plant sap. If the plant is severely damaged, it grows stunted. Punctured buds will result in stunted or absent buds.
You can do that
Check the plants in the cooler morning hours, because at this time the leaf bugs, which are about five millimeters in size, are still rigid and not very flexible. Lacewings are important natural enemies. Chemical control by spraying should only be carried out in the case of a strong spread.
catchy tunes
These insects are usually considered beneficial as they eliminate colonies of aphids, mites and caterpillars. If this food source is missing, earwigs switch to plant parts. They leave marks on the flowers and eat stamens as well as young leaves and buds. Fighting is not recommended.
How to relocate earwigs:
- Fill the clay pot with newspaper and wood shavings
- Stretch the wire mesh over the opening
- Hang daytime roosts in the dahlia stocks
- Move pots to fruit trees in the morning
spider mites
Whitish to yellowish speckles indicate sucking injuries caused by mites. In the case of a severe infestation, leaves and buds appear pale, yellowish-grey and dried up. If you take a closer look, you can see a fine web between the leaves and on the underside of the leaves, in which the red arachnids cavort.
Prevent an infestation
Spider mites depend on long dry periods that are as warm as possible, which is why they occur particularly frequently in stocks if the location is unfavorable. Encourage beneficial enemies such as lacewings, predatory mites and ladybugs.