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Horse chestnut leaf miner - Cameraria ohridella

Leaf mines of Cameraria ohridella on horse chestnut
Leaf mines of Cameraria ohridella on horse chestnut,
Wimbledon, London, July 2003

The Horse Chestnut Leaf Miner was first observed in Macedonia in northern Greece in the late 1970's, and was described as a new species of the genus Cameraria in 1986. In 1989, it appeared unexpectedly in Austria and has since spread throughout central and eastern Europe. Its current distribution includes Belgium, The Netherlands, Denmark, southern Sweden, all of Germany, Poland and the central European countries, and it is currently spreading west through France and south through Italy. Since 2002 it has been reported from Spain, Albania, Turkey, Ukraine, Moldova, Belarus and western Russia.

Cameraria ohridella was first found established in the UK in the London Borough of Wimbledon in July 2002. Leaf mines with larvae were present in high densities on horse-chestnut trees (Aesculus hippocastanum) along the southern edge of Wimbledon Common, and in nearby streets and gardens, which suggested that the first moths had arrived in either 2000 or 2001. From this initial area of infestation, the moth has spread rapidly, and it is now present across most of south-central England, East Anglia and the Midlands. The current distribution (November 2006) extends to Wells on the north Norfolk coast, and to Derby, Shrewsbury, Cardiff and Somerset, 190-230 km from the site of the original infestation. The rate of spread in the UK (40-60 km/year) is similar to that seen on the continent.

Current records of Cameraria in Great Britain

The red dot indicates the location of the original infestation in Wimbledon in 2002.

See also Distribution maps for C. ohridella in the UK 2003 to 2010

Means of spread

Dispersal of the moth from infested areas occurs on a broad front through adult flight, assisted by the wind, and through the passive transport of adult moths or infested leaves in or on cars and other vehicles. Transportation by vehicles appears to be responsible for the sudden appearance of the moth in towns and cities a long way from known areas of infestation.

Help us to monitor the spread of C. ohridella in the UK

Exotic Pest Alert

Horse Chestnut LeafminerAn Exotic Pest Alert on C. ohridella was published in April 2002 and distributed to specialists in the field. The Alert gives further information on the pest and photographs of the main life-cycle stages.

Horsechestnut leaf miner pest alert (PDF-179K)

Order printed copy of the pest alert

The Alert is being re-issued as an Information Note.

See also: