Fenusa ulmi Sundevall, 1847.
miner: Very clear blotch, containing a yellow white larva. The final mine may occupy a sizable part of the leaf. The mine usually starts in a vein axil, never at the leaf margin (Liston, 1994a); in large leaves the mine remains confined between to lateral veins. Frass in black grains, initially often in long pearl chains, in older mines in loose grains. (Bladmineerders van Europa).
mine is also illustrated in British
The larvae of sawflies have a head capsule, chewing mouthparts with opposable mandibles, six thoracic legs and abdominal legs (although they may be reduced) (see examples).
Normally the larva lies venter-upwards in the mine. The small warts on segment 9, and frontal of the rearmost prolegs, are practically unpigmented in some specimens! ( Bladmineerders van Europa.
The pupae of sawflies have visible head appendages, wings and legs which lie in sheaths.
Adult: Details unknown.
Hosts in Great Britain & Ireland:
of year - larvae: Mines in May-June, sometimes numerous (Bladmineerders van Europa).
of year - adults: Currently unknown.
in Great Britain & Ireland: Widespread in England (NBN
NBN Interactive Grid Maps of known host species:
elsewhere: Widespread in continental Europe including Austria,
Belgium, Croatia, Czech Republic, Estonia, Finland, French mainland, Germany, Italian mainland, Latvia, Poland, Slovakia,
Sweden, Switzerland, and Ukraine (van Achterberg
in Fauna Europaea).
British and Irish Parasitoids in Britain and elsewhere: