If the leaves of your currant have blisters, it is probably caused by the currant blister aphid. We'll show you how to get rid of them.
If unsightly blisters appear on the leaves of the currant, the currant blister aphid is usually active. An infestation by the pest is usually harmless and does not damage the plants permanently. Early infestation impairs the development of shoots and leaves. Furthermore, the pest is under discussion as a carrier of the other banding. So that this virus transmission does not occur and the plants suffer lasting damage, hobby gardeners should take appropriate countermeasures and fight the currant blister louse.
Distribution of the currant bladder louse
The eggs of the currant bladder aphid are laid on the leaves of the plant in autumn and usually survive the winter without being damaged. When the plants begin to sprout in spring, the lice hatch as well. These extract the sap from the young leaves. In early summer, the currant bladder aphid leaves its host plant and populates other herbaceous garden plants. In the fall, the pests return to the currant plants and begin laying eggs.
Pests of the currant bladder louse
In spring, the characteristic blisters appear on the upper side of the leaves. The color of the bumps varies between currant varieties.
Currant variety
• Red currant
• Black currant
• White currant
Color of the damage
• reddish and conspicuous
• yellowish-green, rather inconspicuous
• yellowish, rather inconspicuous
Tip: Often, the infestation is only recognized quite late, as isolated leaf arches appear quite inconspicuous.
The currant bladder aphid sucks on the underside of the leaf. There, the pests can usually even be spotted with the naked eye.
The lice leave honeydew on the leaves and fruits, which promotes the development of sooty mold fungi. If younger plants are affected, they can only develop more slowly. This can result in leaf dropping. Leave heavily infested plantsrecognize stunted shoots. This leads to delayed fruiting for the coming harvest year.
Control measures
If the infestation is detected early, the blackcurrant bladder aphid can be controlled quite easily and without the use of chemical agents. Natural pest control in the allotment garden should be given priority in order to do justice to the environment and protect other beneficial insects.
Remove affected plant parts
In a lighter infestation, only a few leaves are affected. All affected plant parts are removed. This should be done before the pests retreat from the currant bush and attack other herbaceous plants in the garden. The leaves can be easily removed with garden shears and then disposed of in the compost bin.
Spread out beneficial insects
The currant bladder aphid has a number of predators, which is why pest control with beneficial insects is a good idea. This method is most successful if the infestation is detected early and has not yet spread to the entire plant.
Lacewing or ladybird larvae can be used. Appropriate beneficial insect boxes are commercially available. These can be applied directly to the affected leaves and the larvae are prevented from falling off the leaves of the currant bush.
Use of natural resources
If the infestation is more severe and repeats every year, it is advisable to use a natural emulsion against the pests.
You can make these yourself as follows:
- two liters of water
- 60 milliliters cooking oil
- two teaspoons baking soda
- four teaspoons dish soap
Mix the ingredients together and pour into a spray bottle. The plant is sprayed generously in early spring when the buds begin to swell and before the first shoots appear. The oily emulsion destroys the larvae by clogging their respiratory openings. Addition of baking soda causes slight decomposition.
Prevent infestations
If you want to forestall a possible infestation, make sure your currant plants are strong and he althy. The soil should be upgraded annually with compost. This natural long-term fertilizer provides the plant with all the necessary nutrients. Horn meal can be used as fertilizer between March and April.
Tip: The fertilizers used should be low in nitrogen.
At onesevere infestation, it is advisable not to just cut off the leaves, but to remove the branches completely. Establishing beneficial insects in the immediate vicinity of the plant also prevents infestation.
When planting, you can use varieties that are less susceptible to the currant blister aphid. Appropriate varieties can be found in the "Descriptive List of Strawberry Fruit Varieties" published by the Federal Plant Variety Office.
Whitecurrant
• Zitavia
• Primus
• White Dutch
• White long-true
Red Currants
• Rose Hollander
• Heinamnns Rote Spätlese
• Red Lake