Galls in gardens
 
By Peter Shirley British Plant Gall Society                  reviewed by Steve Head
 
Many garden plants are hosts to gall-causing insects, mites and fungi. Their galls are often complex and colourful and often harmless, although some can be serious pests of fruit and vegetables. Many can easily be identified (see references and images below) and learning to find and recognise them opens up a new dimension for wildlife gardeners.
 
The main groups of mite and insect gall-causers are eriophyid mites, gall midges and gall wasps. Other insect gall causers include some psyllids, aphids, flies other than midges, beetles, moths and sawflies. Galls are found on trees and shrubs and on many herbaceous plants, including grasses and ferns. They come in a wide variety of forms and sizes and may be very prominent or very obscure. Many are virtually hidden inside shoots, branches and flower stems. Insect and mite causers are wholly or partly enclosed by their galls, which provide them with nutrition as well as shelter and protection.
 
Most gall-causers are associated with particular species or genera of host plants. Well known examples include oak apples, robin’s pincushions on wild roses, nail galls on maples, limes and other trees, and red bean galls on willows and sallows.
 
The number of species and their range in Britain is constantly changing, not least because of the horticultural trade. A recently introduced psyllid Trioza alacris producing galls on bay has been spreading north, and a mite on Fuschia, Aculops fuchsiae first recorded at Kew in 2007, may be establishing itself in southern Britain. These and eight other galls likely to be found in gardens and allotments are described and illustrated below. Members are invited to report their presence to Peter Shirley (petershirley@blueyonder.co.uk). Records of other galls in gardens will also be welcome, and following verification they will contribute to The British Plant Gall Society’s expanding database of gall records.
 
Gall made by a fungus
 
Taphrina padi "tongue gall" fungus on Prunus species
There are two galled and two nomal fruits.
 
 
THE BRITISH PLANT GALL SOCIETY
 
BPGS encourages and coordinates the study of plant galls, with particular reference to the British Isles. We have a gall recording scheme, publish keys to, and books about, plant galls, organise field meetings and gall gathering weekends, workshops on gall ecology, and offer identification services. Members receive our twice yearly bulletin 'Cecidology' and we participate in ispot.
 
Our website is http://www.british-galls.org.uk/
 
Find us on Twitter @britgalls
 
 
 
 
Galls made by mites
 
 
 
 
 
Aculops fuchsiae mite on Fuchsia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Eriophyes pyri mite on Rowan - late stage
 
 
 
 
 
 
 
 
 
 
 
 
Aceria labiatiflorae on wild Marjoram
Galls made by Hemiptera
 
 
 
 
Trioza alacris psyllid on Bay 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Cryptomyzus ribis Red currant aphid on currant (Ribes)
Galls made by midges (Diptera: flies)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Dasineura urticae gall midge on Stinging nettle
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Rhopalomyia tanaceticola gall midge on on Tansy
 
 
 
 
 
 
 
 
 
 
 
 
 
Dasineura gleditchiae gall midge on Honey Locust
 
 
 
 
 
 
 
 
 
 
 
Galls made by gall wasps
 
 
 
 
 
 
 
 
Aylax papaveris gall wasp on Poppy. Galled seed heads are bloated, normal (dead) head on the left.
 
For more gall wasps see our page here.
       Garden Wildlife
             Garden Wildlife
Galls made by mites
 
 
 
Aculops fuchsiae mite on Fuchsia
 
 
 
 
 
 
 
 
 
Eriophyes pyri mite on Rowan
- late stage
 
 
 
 
 
 
 
 
 
 
 
 
Aceria labiatiflorae on wild Marjoram
Galls in gardens
 
By Peter Shirley British Plant Gall Society     reviewed by Steve Head
 
Many garden plants are hosts to gall-causing insects, mites and fungi. Their galls are often complex and colourful and often harmless, although some can be serious pests of fruit and vegetables. Many can easily be identified (see references and images below) and learning to find and recognise them opens up a new dimension for wildlife gardeners.
 
The main groups of mite and insect gall-causers are eriophyid mites, gall midges and gall wasps. Other insect gall causers include some psyllids, aphids, flies other than midges, beetles, moths and sawflies. Galls are found on trees and shrubs and on many herbaceous plants, including grasses and ferns. They come in a wide variety of forms and sizes and may be very prominent or very obscure. Many are virtually hidden inside shoots, branches and flower stems. Insect and mite causers are wholly or partly enclosed by their galls, which provide them with nutrition as well as shelter and protection.
 
Most gall-causers are associated with particular species or genera of host plants. Well known examples include oak apples, robin’s pincushions on wild roses, nail galls on maples, limes and other trees, and red bean galls on willows and sallows.
 
The number of species and their range in Britain is constantly changing, not least because of the horticultural trade. A recently introduced psyllid Trioza alacris producing galls on bay has been spreading north, and a mite on Fuschia, Aculops fuchsiae first recorded at Kew in 2007, may be establishing itself in southern Britain. These and eight other galls likely to be found in gardens and allotments are described and illustrated below. Members are invited to report their presence to Peter Shirley (petershirley@blueyonder.co.uk). Records of other galls in gardens will also be welcome, and following verification they will contribute to The British Plant Gall Society’s expanding database of gall records.
 
Gall made by a fungus
 
Taphrina padi "tongue gall" fungus
on Prunus species. There are two galled
and two nomal fruits.
 
 
Galls made by midges (Diptera: flies)
 
 
 
 
 
 
 
 
Dasineura urticae gall midge on Stinging nettle
 
 
 
 
 
 
 
 
 
 
 
 
 
Rhopalomyia tanaceticola gall midge
on on Tansy
 
 
 
 
 
 
 
 
 
Dasineura gleditchiae gall midge on Honey Locust
 
 
 
 
 
 
Galls made by gall wasps
 
 
 
Aylax papaveris gall wasp on Poppy. Galled seed heads are bloated, normal (dead) head on the left.
 
For more gall wasps see our page here.
Galls made by Hemiptera
 
 
 
Trioza alacris psyllid on Bay 
 
 
 
 
 
 
 
 
 
Cryptomyzus ribis Red currant aphid on currant (Ribes)
THE BRITISH PLANT GALL SOCIETY
 
BPGS encourages and coordinates the study of plant galls, with particular reference to the British Isles. We have a gall recording scheme, publish keys to, and books about, plant galls, organise field meetings and gall gathering weekends, workshops on gall ecology, and offer identification services. Members receive our twice yearly bulletin 'Cecidology' and we participate in ispot.
 
Our website is http://www.british-galls.org.uk/
 
Find us on Twitter @britgalls