Comment: The senior name is Orchestes hortorum (Fabricius, 1792) and will be included as such in the next Coleoptera Checklist (2016) (pers.comm Colin Plant ex Andrew Duff).

Leaf-miner: A gallery along the edge of the leaf leading to a circular blotch, from which a case is cut leaving a round hole (British leafminers, as O. signifer).

Rather short corridor along the leaf margin, widening into a circular blotch that usually is free from the margin. The mature larva makes an excision that includes almost all of the blotch, and thus sandwidched drops to the ground for pupation (Bladmineerders van Europa).

Larva: The larvae of beetles have a head capsule and chewing mouthparts with opposable mandibles and lack abdominal legs (see examples).

The larva is illustrated in (British leafminers, as O. signifer) and Bladmineerders van Europa.

Orchestes avellanae larva, dorsal Image: © Willem Ellis (Bladmineerders van Europa)

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

Hosts in Great Britain and Ireland:

Betulaceae
Corylus				British leafminers, as O. signifer
Corylus	avellana	Hazel		Plant, in Pitkin & Plant, 2005
Fagaceae
Quercus				British leafminers, as O. signifer

Hosts elsewhere:

Time of year - mines: Univoltine: early summer (British leafminers, as Orchestes signifer).

Time of year - adults: Currently unknown.

Distribution in Britain: Widespread including Bedfordshire, Berkshire, Buckinghamshire, Cambridgeshire, Cheshire, Cumberland, Derbyshire, Dorset, Dumfriesshire, East Cornwall, East Gloucester, East Kent, Est Kent, East Norfolk, East Suffolk, Glamorgan, Herefordshire, Kirkcudbrightshire, Leicestershire, Merionethshire, Mid-west Yorkshire, Middlesex, North Essex, North Somerset, Northamptonshire, Nottinghamshire, Pembrokeshire, Radnorshire, Shropshire, South Hampshire, South Wiltshire, South-west Yorkshire, Stafford, Surrey, Warwickshire, West Gloucestershire, West Kent, West Norfolk, West Suffolk, West Sussex, Westmorland and Worcestershire (NBN Atlas, as Orchestes signifer).

Distribution elsewhere: Europe including Bulgaria, ? Corsica, Czech Republic, Danish mainland, French mainland, Germany, Italian mainland, Moldova, Norwegian mainland, Poland, Russia - East and Northwest, Sardinia, Sicily, Slovakia, Switzerland Yugoslavia. Also recorded in the Near East (Fauna Europaea).

NBN Atlas links to known host species:

Parasitoids: