Blackberry gall mites work in secret because they are simply too small for the human eye. But the result of their sucking activity must be noticed by every owner. The reason: mainly fruits are affected! It's high time to at least save the following year's harvest.
How do I fight gall mites on blackberries?
In summer, the gall mites are well hidden in the growing fruits and therefore cannot be combated effectively. After a severe infestation, you should remove the gall mites overwintering in the bush with astrong pruningand, if necessary, also carry out ashooting spray.
What damage is typical for gall mites?
The white, 0.1 to 0.17 millimeter small blackberry gall mites (Acalitus essigi) are not visible to the naked eye. They sit on the base of the fruit, from where they suck on the berries. Visible symptoms of an infestation areunevenly ripened fruits While part of an affected fruit is colored black, typical of ripening, the rest remains red. If the infestation is very severe, the blackberry bush may only bear red (unripe) fruits at harvest time. The red segments will eventually dry up.
Why often only part of a berry remains unripe?
We perceive the blackberry as a single fruit. But it is actually a so-called collective drupe, which is made up of several small, round fruits. It is usually the case thatonly some fruits are pierced by gall mites and sucked out, while others can continue to ripen normally. This explains the different coloring and the “partial ripeness”.
How do I combat gall mites with pruning?
Gall mites overwinter on the stem parts. Fruit mummies that get stuck are also used as winter hiding places. In spring the pests then move into the flower buds and the damage begins. To prevent this, you must remove them from the bush in good time.
- in autumn or spring cutting
- cut back all infected bushes close to the ground
- Burn clippings or dispose of in household waste
- never leave it lying around for long, do not compost
When and how is a shoot spray carried out?
The shoot spraying is never carried out preventatively, as the spray can also harm beneficial insects. Therefore, only spray after a severe infestation.
- spray in spring of the following year
- when the new side shoots are approx. 20 cm long
- wait for an overcast day
- use an approved spray agent
- z. B.rapeseed oil based
- Repeat treatment several times
The fine oil film sticks together the respiratory organs of the gall mites and causes them to suffocate very quickly. Canola oil sprays are not harmful to blackberry plants or people. You can pick and eat fruits that form afterwards without hesitation.
Can I prevent gall mites?
Care for your blackberry plants as needed so that they grow strong. Then they are less susceptible to diseases and pests. Since the blackberry gall mite spreads when it is dry and warm, you should keep the root area of your blackberries moist with a layer ofmulch, especially in summer. Plant blackberries with enough spacing to allow air to circulate well. In addition, you should not fertilize them with a fertilizer that contains too much nitrogen.
Tip
Also check other berry bushes for gall mites
The family of gall mites (Eriophyidae) is large and has its own species for each berry fruit. Therefore, keep an eye on strawberries, currants and grape vines, which also often suffer from gall mites, sometimes with slightly different symptoms.
