The fuchsia gall mite (Aculops fuchsiae) is a microscopic creature, but it has a profound effect on fuchsia plants. It was first discovered in Brazil as recently as the 1970s and it has since spread to other parts of the world, including California, France, Germany and the Channel Islands. The mite was found for the first time on the mainland of Britain in early September 2007 when samples of infested fuchsia plants were sent to the RHS members' advisory service at RHS Garden Wisley. The affected plants were previously healthy hardy fuchsias that had been growing in a private garden near Fareham, Hants, for about 20 years. As damage on infested plants is very distinctive, it is unlikely to have gone unnoticed for long, so it is likely that there are other infested plants in the Fareham area, from which the mite spread to the 20-year old plants.
Later in 2007, the mite was also found in two other gardens in Middlesex and Kent.
The gall mites are about 0.25mm long and too small to be seen without a microscope. They infest the new growth at the shoot tips where they feed by sucking sap. They also secrete chemicals into the plant that prevent the normal development of leaves and flowers. As the infestation increases, the plant produces increasingly distorted foliage until it is no longer able to produce normal leaves or flower buds. This results in the shoot tips producing a mass of yellowish green
or reddish-pink
distorted tissue instead of leaves or flower buds. Pictures of damaged plants can be seen on the DEFRA Plant Health website.
Fuchsia gall mite probably first arrived in Britain at some time during late 2006/2007. It may have been introduced by the nursery trade on imported pot plants, or it could have been brought here on a cutting collected by someone who had been staying in the Channel Islands or the Brittany region of France, where the mite is now widespread. Being a tiny animal, the gall mite cannot travel far by its own means but while crawling around it might get blown by the wind to another plant. It could also hitch a ride on insects and other animals that alight on infested fuchsias.
The mite has several generations between late spring to autumn and it takes about 21 days to complete its life cycle at a temperature of 18°C (64°F). It overwinters under bud scales but may remain active during the winter on glasshouse fuchsias. The mite cannot survive temperatures below 5°C (41°F) and so cold winters may kill it on hardy garden fuchsias. However, cold winters are becomingly a thing of the past in the south of England and in city centres, where sheltered conditions may allow the mite to survive winter out of doors.
Gardeners who suspect they have infested fuchsias should contact their local DEFRA Plant Health and Seeds Inspectorate office, listed in phone books under Department of Environment, Food and Rural Affairs. Samples of suspected infested plants can be sent in sealed polythene bags to PHSI, Central Science Laboratory, Sand Hutton, York YO4 1LZ, with details of where the plants are growing. PHSI inspectors are currently assessing the extent of the infestation in Britain. If the pest is not too widespread, it may be possible to eradicate it. However, if it is already present in many gardens, then it is likely that fuchsia gall mite is here to stay.
Home gardeners have limited options for dealing with this pest. Gall mites in general are relatively tolerant of pesticides and most of those in home garden products will be ineffective. Bifenthrin, which is sold as Scotts Bug Clear Gun, Bayer Sprayday Greenfly Killer Plus or Doff All In One Garden Pest Killer may give some control if applied when symptoms start to appear. Cutting off infested shoot tips will remove many mites but regrowth is likely to become infested.
In California, it has been noted that that some Fuchsia species and cultivars appear to be resistant to this pest. Susceptible species are Fuchsia arborescens, F. magellanica and F. procumbens. Many commonly grown cultivars are likely to susceptible; those affected in the garden near Fareham were 'Mrs Popple' and 'Margaret Brown'. Species and cultivars noted as being resistant, and which are listed in RHS Plant Finder as being available from one or more UK nurseries, are 'Baby Chang', 'Cinnabarina', 'Mendocino Mini', ' Miniature Jewels', 'Space Shuttle', Fuchsia microphylla subsp. hidalgensis, Fuchsia thymifolia and Fuchsia venusta.