Red convex spots on the currant leaves , resembling blisters, are the result of aphid feeding. In spring, the currant is attacked bycurrant-purgatory aphidbut symptoms in the form of red blueprints and distortions on the leaves may persist until autumn. See howcombating aphids on currantsand how to prevent raised red spots from appearing on currant leaves!
Red convex spots on currant leaves are a symptom of feeding the currant aphid
Fig. forum.PoradnikOgrodniczy.pl
Red bulges and deformations on currant leaves are caused by the currant aphid(Cryptomyzus ribis). Such changes on currant leaves appear in spring. To make sure that there are aphids on the currant, it is worth turning the leaf over and looking at its underside. Then we will notice a lot of small insects. They puncture the leaf tissues, sucking the juices out of them and contributing to deformation. In the place of their feeding, on the other side of the leaf, there will be protrusions.
The currant-purgatory aphid feeds mainly in early spring , but damaged leaves remain on the shrubs until autumn. On the currant, the pest remains until June, and 3 or 4 generations develop during this time. Later, the aphid is transferred to the secondary host, i.e. purgatory. In autumn, the aphid returns to the currants to lay eggs on their shoots. The eggs hibernate on the currant and new aphids will hatch in spring.
Aphids on the underside of a currant leaf
Fig. I. Sáček senior, CC0, Wikimedia Commons
Fighting the currant-purgatory aphid
In spring, after noticing the first red, convex spots on the currant leaves , we should remove leaves with such symptoms.Remove all leaves on which aphids are feeding(to do this, we check the underside of the leaf and look for pests). If there are no aphids on the leaf, its removal no longer makes sense (we only get rid of the leaves with feeding insects and destroy them). In this way, we will prevent the development of the next generations of the pest.
Along with aphids, useful ladybugs appear on currants, which eat harmful aphids
Fig. I. Sáček senior, CC0, Wikimedia Commons
In this period, it is also worthspraying against aphidsIt is best to use organic preparations based on natural ingredients, such as potassium soap with garlic (the smell of garlic deters aphids) and the oil preparation Emulpar 940 EC (oil clogs aphids' breathing holes and causes suffocation).In the case of a large number of aphid infestations, you can use chemical pesticides, such as Mospilan 20 SP or Karate Zeon 050 CS, but in the case of amateur crops in gardens, I encourage you to avoid it. As a rule, aphids on currants do not cause such large losses that it is impossible to do without spraying with protective agents.
Note!A common mistake is to spray in the summer when the aphids on the currant are gone. Then it makes no sense (we only pollute the environment, harm bees and other beneficial insects). Therefore, before spraying, always check the underside of the leaf to make sure that aphids are still there. The distortions and raised red spots on the currant leaves remain until autumn, but the pests are no longer there.
The only thingthat we can do in the summer, when the aphids on the currant are gone , is to regularly irrigate the bushes and apply fertilization to support the regeneration of currants with red spots and blisters on the leaves. Bushes weakened by aphids need such help.
If on the currant we have observed red bumps and bubbles, indicating the presence of aphids, it is worth applyingspraying against winter aphid eggsFor this purpose, we use oil preparations - the aforementioned Emulpar 940 EC or Promanal 60 EC. We spray with oil preparations in March, before the vegetation starts. In this way, we will reduce the risk of aphids appearing in the spring season.
Note!
If you can see red or brownish-brown spots and discoloration on the currant leaves, but they are not raised or bulging, and there is no presence of aphids on the lower side of the leaf, these diseases may be: white currant rust or anthracnose (leaf fall) of the currant. It is also possible that the red discoloration of the leaves is caused by a phosphorus deficiency in the soil.
All the above-mentionedsprays to combat aphids on currantscan be ordered in the shop of our guide. We guarantee attractive prices, high quality of preparations and fast shipping. Press the button below to view.
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