1 > Leaf-miner: A
narrow linear leaf-mine, which developes into a large blotch. Several
larvae frequently feed together and the resulting mine can entirely
fill the leaf (Spencer, 1976:
89).
The
mine begins with a narrow, parallel sided corridor af 1-8 cm in
length, with a nice double frass line. After the first moult the
corridor is succeeded, and mostly overrun, by a large, primary,
brown blotch. Frass in the initial corridor in short thread fragments,
in the blotch in angular granules and thread fragments that often
are branching (the frass is unusally sticky). Primary and secondary
feeding lines conspicuous. The final mine often is very large and
generally contains several larvae, because normally several mines
develop on a leaf, and coalesce into one big blotch. Before pupation
the larvae leave the mine through a semicircular exit slit that
mostly, but not invariably, is in the upper epidermis.
The initial narrow gallery contains frass in a double line. It then expands to form a blotch mine. Several larvae may occupy a leaf to form a large blotch. |
On
numerous genera of Boraginaceae, including Anchusa, Borago, Cynoglossum, Echium and Pulmonaria, but not yet on Amsinckia, in Britain. Widespread
in Britain. Also recorded in the Republic of Ireland. Common and
widespread throughout most of Europe.
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