The leaf and stem mines of British flies and other insects

(Coleoptera, Diptera, Hymenoptera and Lepidoptera)

by Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds


Caloptilia betulicola (M. Hering, 1928)
[Lepidoptera: Gracillariidae]

Red Birch Slender

Gracilaria betulicola M. Hering, 1928. Z. angew. Ent. 13: 168
Caloptilia betulicola
(M. Hering, 1928).

Leaf-miner: The larva mining the leaves initially and then living inside a rolled leaf in later instars (UKMoths).

The mine starts with an unconspicuous epidermal corridor, mainly visible by a reddish brown frass line. During the following larval stage a blotch is formed, that quickly develops into a tentiform mine; the epidermis is brown. Generally the mine is lower-surface, but upper-surface mines are not rare. Frass in a mass of grains in a corner of the mine. After having left its mine the larva moves twice. First it lives in a rolled (sometimes just folded) leaf margin, after that in a leaf that is transverely rolled downwards, starting from the leaf tip (Bladmineerders van Europa).

Larva: The larvae of moths have a head capsule and chewing mouthparts with opposable mandibles (see video of a gracillarid larva feeding), six thoracic legs and abdominal legs (see examples).

Whitish with pale brown head; pronotum without black spots (Bladmineerders van Europa).

Pupa: The pupae of moths have visible head appendages, wings and legs which lie in sheaths (see examples).

Pupation in a white, strongly shining, parchment-like cocoon that is fixed with silk to the leaf margin (Bladmineerders van Europa).

Adult: The adult is illustrated in UKMoths and the Encyclopedia of Life. The species is included in

Hosts in Great Britain and Ireland:

Betula       British leafminers
Betula       UKMoths

Hosts elsewhere:

Betula pendula Silver Birch British Wild Flowers by John Somerville et al. Belgian Lepidoptera
Betula pendula Silver Birch British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Betula pubecens Downy Birch British Wild Flowers by John Somerville et al. Belgian Lepidoptera
Betula pubecens Downy Birch British Wild Flowers by John Somerville et al. Bladmineerders van Europa

Time of year - larvae: May, July (British leafminers).

Time of year - adults: Two generations. June and July and then September and October. The second brood overwinters as an adult and often reappears in the early spring (UKMoths).

Distribution in Great Britain and Ireland: Britain including Leicester (Pickworth Woods) (UKMoths); Bedfordshire, Breconshire, Buckinghamshire, Caernarvonshire, Cambridgeshire, Carmarthenshire, Cheshire, Denbighshire, Dorset, Dumfriesshire, Dunbartonshire, Durham, East Cornwall, East Kent, East Norfolk, East Ross, East Suffolk, East Sutherland, Easterness, Elgin, Glamorgan, Haddington, Hertfordshire, Huntingdonshire, Kincardineshire, Kirkudbrightshire, Linlithgow, Merionethshire, Middlesex, North Aberdeenshire, North Devon, North Essex, North Hampshire, North Northumberland, North Somerset, Nottinghamshire, Outer Hebrides, Pembrokeshire, Shropshire, South Aberdeenshire, South Devon, South Northumberland, South Somerset, South Wiltshire, South-west Yorkshire, Stafford, Stirlingshire, Surrey, Warwickshire, West Gloucestershire, West Kent, West Lancashire, West Norfolk, West Perthshire, West Ross, West Suffolk, Westmorland, Wigtowwnshire and Worcestershire (NBN Atlas). See also British leafminers distribution map.

Also recorded in the Republic of Ireland and Northern Ireland (Fauna Europaea and National Biodiversity Data Centre Map).

Distribution elsewhere: Widespread in continental Europe including Austria, Belgium, Czech Republic, Danish mainland, Estonia, Finland, French mainland, Germany, Latvia, Norwegian mainland, Poland, Russia - Central, North and Northwest, Slovakia, Sweden, Switzerland and The Netherlands (Fauna Europaea).

NBN Atlas links to known host species:

Betula pendula, Betula pubecens

British and Irish Parasitoids in Britain and elsewhere:

Sympiesis dolichogaster Ashmead, 1888 Eulophidae: Eulophinae
Ichneumonoidea - Links to species no longer available  
Apanteles xanthostigma (Haliday, 1834) Braconidae: Microgastrinae
Dolichogenidea dilecta (Haliday, 1834) Braconidae: Microgastrinae
Rhysipolis decorator (Haliday, 1836) Braconidae: Rhysipolinae
Rhysipolis meditator (Haliday, 1836) Braconidae: Rhysipolinae
Diadegma stigmatellae Horstmann, 1980 Ichneumonidae: Campopleginae
Bathythrix prominens (Strobl 1901) Ichneumonidae: Cryptinae
Diaglyptidea conformis (Gmelin, 1790) Ichneumonidae: Cryptinae
Gelis areator (Panzer, 1804) Ichneumonidae: Cryptinae
Gelis fuscicornis (Retzius, 1783) Ichneumonidae: Cryptinae
Itoplectis aterrima Jussila, 1965 Ichneumonidae: Pimplinae
Scambus inanis (Schrank, 1802) Ichneumonidae: Pimplinae

External links: Search the internet:

Belgian Lepidoptera
Biodiversity Heritage Library
Bladmineerders van Europa
British leafminers
Encyclopedia of Life
Fauna Europaea
NBN Atlas
NHM UK Checklist

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Last updated 11-Jul-2019  Brian Pitkin Top of page