The gall mites, which are no more than 0.5 mm in size, still make life difficult for the hobby gardener when they mess with the plants in the garden. The sucking pests cause nodule- and cone-shaped deformations known as galls. In late summer and autumn, the often red-colored galls can be seen with the naked eye. But then it is already too late to combat it, because the mites are in a protected environment, which makes it very difficult to counteract them. So it depends on the right time if gall mites are to be successfully combated.
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Gall mites attack these plants
Since gall mites prefer a dry and warm environment, the following host plants are at risk from infestation:
- Bramble bushes
- Raspberry bushes
- Red and black currant
- Plum tree
- Conifers
- maple
- beech
- Linde
- alder
- fiction
- hazelnut
- Dogwood
In the case of the conifers, no protuberances are formed as damage, as on the leaves of the berry bushes and deciduous trees. Rather, the needles turn brown because they are hollowed out by the gall mites and ultimately fall off. In the berry bushes, the pests spread especially in the fruit stands and usually prevent ripe or unsavory deformed fruits from forming.
Fight gall mites biologically
If the gall mites have spent the winter undetected in the leaf axils, between the scales of buds or in the fruit mummies of their host plants, they march off in spring when budding begins and overrun the young leaves or needles. Environmentally conscious gardening enthusiasts do not take the ‘chemical club’ directly, but use biological control agents, which are particularly successful if they are precisely tailored to the type of host plant. This is all the more important as specialists have developed within gall mites:
Get rid of blackberry and raspberry gall mites
Since the pests attack the unripe fruits, in the worst case they cause a complete harvest failure:
- Prefer early varieties.
- Always remove fruit mummies.
- Carry out regular pruning.
- Keep the soil moist with a layer of mulch.
- Do not supply the bushes with high-dose nitrogen fertilizers.
- Shower bushes with water in dry periods.
- Apply rapeseed oil-based insecticide.
- First use with a shoot length of 10 cm.
- Second application after 10 days.
- Third application just before full bloom.
In biological pest control, various insecticides with rapeseed oil are permitted for private use.
Cure plum tree from gall mites
If numerous small galls appear on the leaves that resemble warts, this is an indication of the infestation with gall mites. They mostly overwinter in the bark or in the buds before they become active in spring.
- Regularly loosen the soil under the tree.
- Water abundantly during dry periods.
- Cut off the infected leaves.
- Dispose of with household waste.
- Carry out shoot spraying in early spring.
- Injecting rapeseed oil preparations several times at intervals of several days.
- Do not spray young leaves.
- Do not use the product under the blazing sun.
- Use for several years in a row if infected.
In the case of pome and stone fruit, only one spraying agent that contains rapeseed oil is currently approved for hobby gardeners, namely ‘Pest-free Naturen’ from Celaflor. Since changes occur almost every day in this regard, the experienced gardening enthusiast can obtain information about this topic from the plant protection database on a daily basis. Although pesticides containing rapeseed oil are completely harmless to health, experts recommend that you do not harvest the sprayed trees until after three days at the earliest.
The damage caused by gall mites on deciduous and coniferous trees is not nice to look at, but does not cause any serious damage. If you still want to eliminate the nuisances, pay attention to the following tips and hints.
Effective control methods on all infected plants
In addition to the biological insecticides with rapeseed oil, various infusions and liquid manure that you can make yourself have proven themselves:
Tansy Sud
Tansy is a slightly poisonous plant from the daisy family, which can often be seen along the wayside with its yellow, button-like flowers. For the brew, 150 g of fresh leaves are roughly chopped and 5 liters of boiling water are poured over them. Let it steep for 10 minutes and then filter. The endangered plants are sprayed dripping wet 3 times at an interval of 10 days.
Wormwood
In the herb garden wormwood is a loner because its root excretions can damage neighboring herb plants. As a biological control agent against gall mites, wormwood can do something useful and kill the pests. 150 g of fresh, finely chopped wormwood is poured over 5 liters of boiling water. After 30 minutes, the broth can be filtered. The raspberry gall mites in particular cannot tolerate a three-time spray 10 days apart.
Garlic
If applied in good time, a brew of 100 g of garlic soaked in 20 ml of oil for 25 hours works. After this time, 1 liter of water and 10 ml of pure curd soap are added. This mixture is diluted 1:20 before use.
Nettle
Resourceful researchers have found that fungicides used against powdery mildew do not spare gall mites either. Therefore, the nettle liquid manure is also used to get rid of the nuisances. Due to the resulting intense smell, a secluded spot in the garden should be chosen for the production. 1 kg of nettles are roughly chopped and soaked in 9 liters of water for 3 days. During this time, the container remains covered and the liquid manure is stirred from time to time. Finally, the gardener filters the liquid manure in order to spray it several times in the early spring at intervals of 3 to 4 days.
Ivy
The poisonous climbing plant is also used by gardeners as a natural weapon against gall mites. To do this, 100 g of ivy leaves are kept in 1 l of water until fermentation begins. Depending on the temperature, the process takes 3 to 5 days. Then the mixture is filtered and diluted to 5% before being applied repeatedly.
Gall mite-resistant berry bushes
A particularly efficient method of preventing gall mites is to plant resistant varieties, preferably. This is especially useful when growing fruit that the family will later consume.
Red currants
- Rovada
- Jonkher v. Tets
Black currants
- Ben Sarek
- Titania
raspberry
- Blissy
- Autumn Bliss
- Rubaca
- Willamette
Blackberries
- Choctaw
- Theodor Reimers
- Lubera Navaho
- Tayberry
plums
- Katinka
- Tegera
- Felsina
- Hanita
In principle, early-ripening fruit types are less at risk of infestation by gall mites than late-ripening ones. It should be noted, however, that early fruit varieties are exposed to damage from late frosts.
Use the natural enemies to fight gall mites
Predatory mites
The predatory mites of the species Amblyseius degenerans and Amblyseius californicus are among the most important natural enemies of gall mites. These beneficial insects are available in specialist shops and on the Internet. They are usually delivered on carrier granules and sprinkled directly onto the infected plants. In the event that they should trickle down from the leaves, the predatory mites are spread on damp kitchen paper that is laid out under the plant. They will find their way up to the gall mites. There the predatory mites attack the gall mites and destroy the adult pests as well as the eggs and larvae. If there are no gall mites left, they migrate without causing any damage to the plant.
Lacewing larvae
Gardening enthusiasts receive additional protection in the fight against gall mites from lacewings, whose larvae are also natural enemies of these pests. These beneficial insects are available in garden centers or in online shops. They are delivered in a honeycomb-like packaging in the 1st or 2nd larval stage. During the application, the dosage instructions should be followed exactly, because in the event of an overdose, the lacewing larvae only eat each other and spare the gall mites. Since they are active for a maximum of 10 to 14 days before pupation, repeated use is usually necessary. The parallel use of additional pesticides will not be used during this period. In particular, chemical insecticides are not used for at least 6 weeks before and 6 weeks after.
The experienced gardening enthusiast is aware that the use of biological control agents in the home garden seldom shows an immediately recognizable result. Anyone who acts according to the motto ‘constant dripping wears away the stone’ in this regard will in the long run get rid of gall mites with a clear conscience towards the environment.
Pesticides that successfully fight gall mites
The last arrow in the quiver of the environmentally conscious hobby gardener are pesticides that are permitted for use in the private sector. In addition to the insecticides that are made on the basis of rapeseed oil, there are two other agents that are currently approved for non-professional users:
Netz-Schwefelit WG von Neudorff
This agent was originally developed to combat powdery mildew and mainly contains sulfur. The fight against gall mites was discovered as a side effect.
Kiron mites ex from Dr. Stähler
With the help of the active ingredient fenpyroximate, this insecticide achieves a quick initial effect against gall mites and also lasts some time in its effectiveness. It is currently on the list of permitted pesticides for allotment gardens with an approval period until 2017.
The following advice for use in the home garden should be taken into account:
- Study the instructions for use and follow them exactly.
- Wear protective clothing, gloves and sturdy shoes.
- Do not eat, drink or smoke at the same time.
- Adhere to the dosage exactly.
- Do not use in rain, wind and blazing sunshine.
- Afterwards clean the equipment carefully and wash your hands.
- Observe regulations for the disposal of residues and packaging.
- Keep out of the reach of children or animals.
The most important requirement for the effectiveness of these remedies is the timely application before the galls form. Once the mites are inside, no insecticide can harm them.
Conclusion
You cannot be seen with the naked eye. When the deformations they cause show on bushes and trees, it is usually too late for successful control. Gall mites are not among the most destructive pests in the garden; the majority of hobby gardeners still do not want to accommodate them. How good that there are a number of biological means to get rid of the nuisances. The point in time plays a decisive role in terms of effectiveness. Environmentally conscious gardening enthusiasts will only resort to chemical insecticides in the last resort. But even these are no longer effective once the mites are in the galls.
