Aculops fuchsiae: causes fuchsia galls

Aculops fuchsiae is a mite of the family Eriophyidae, native to South America, which causes galls on fuchsia. It was discovered in 1981 in the San Francisco area (California, USA). It has since spread rapidly to the south of this region where it causes a lot of damage. It is a quarantine pest for Europe, classified in Annex IIA1 of Directive 92/103/EC.

. Which plants are at risk?
A.Fuchsiae has so far only been found on fuchsia. At least three species are affected (F.arborescens, F.magellanica, F.procumbens). There is considerable variability in susceptibility, some cultivars have been reported to be highly resistant.

. Characteristics of the attack
A.Fuchsiae causes characteristic galls on twigs, leaves and flowers of fuchsia. The galls are deformations sometimes accompanied by a reddish discoloration (see photos). The mites live on the surface of the galls. They can be easily observed with a good magnifying glass. They are very light yellow, elongated, typical of the family Eriophyidae and quite large. The aculops is nicknamed the fuchsia gall, because this biting mite causes swelling of the tissue with gallery formation. After a slight wilting of the terminal buds, the leaves are covered with a white veil resembling a powdery mildew attack.

 

 

Later the affected shoots turn red. Finally, the flowers that develop on this attack become deformed in their turn. I discovered this new parasite in 2003 in the Gulf of Morbihan. Since then, it has progressed according to the more or less hot summers. This mite appreciates cool and humid temperatures and develops through wind, rain and foraging insects.

But after several years of cross-checking, questioning and exchanging information, the most rapid spread is the result of the practice of exchanging and marketing cuttings from a polluted area to an unscathed one. Our fuchsias travel very well and we are now paying the price. Aculops is present in several European countries and the eradication method has shown its limits.

. What to do in case of an attack?

In case of symptoms of galls on fuchsia, cut a piece of branch attacked by the mites and immerse it in 70° alcohol. Then send your sample to the following address.

FEREDEC
280 rue de Fougères
BP 80118
35701 RENNES cedex 7

 

. Means of control

To eradicate this mite, you will have to eliminate the affected branches as soon as the attack begins, by cutting the branches well below the visible part. If the attacks are too important, do not hesitate to cut all your branches at ground level. Our fuchsias are strong enough to regrow very quickly. Do not shake the cut branches, but place a large garbage bag nearby and carefully place them inside. Burn all your waste and disinfect your tools and hands with alcohol as these little beasts are not, unfortunately, visible. As soon as this operation is done, clean the ground and remove 3 to 4 cm of soil on the surface because the mite will fall and attack the tender branches again. Once these cleaning operations are done you can start the different treatments:
- Black soap
- Mineral oils (Alphasis): good results.
- Purins

N.B.: Do not confuse the symptoms caused by Aculops fuchsiae with those caused by lack of light. Indeed, during the end of autumn and winter, badly formed flowers can appear, this is due to the passage from long to short days.

Other pests

- Aphis mymecaria, or greyish white aphid: It attacks the roots.

- Acarius telarius, or red spider: This mite appears in dry periods. Visible to the naked eye, it bites and sucks on the underside of the leaves, which take on a greyish tinge and eventually fall off.

- Thrips: A very small insect, just visible to the naked eye, with an elongated yellow-green shape, which nests in the axils of young shoots and stings especially in hot weather. Fears light, moves at night and causes malformations of young leaves.

- Whiteflies: They reproduce at an astonishing rate and cover the underside of the leaves. They are mainly found in greenhouses and outdoors during hot weather.

- Flea beetles, or ground fleas: Perforate the leaves, attacks take place at night and the flea hides in the soil during the day.