Stem-mine: Oviposition normally takes place near the base of the stem. Larva forming external stem-mine, feeding first upwards for as much as 30 cm, then turning and continuing downwards. A number of larvae may feed in a single stem and young plants may turn yellow and die. Pupation immediately beneath the epidermis (Spencer, 1976: 78).

Oviposition in the rind of the stem, just above the ground. A corridor from there runs upwards for about 30 cm, then reverts and descends to about ground level. Pupation in the mine, just below the epidermis. Usually several mines on one plant; the plant can effectively be ringed and be killed (Bladmineerders van Europa).

Larva: The larva is described by Dempewolf (2001: 79).

Puparium: Pale or darker brown; posterior spiracles each having about 16 bulbs (Spencer, 1976: 78).

Comments: Recently simplex has been treated as a species of Hexomyza. It is a pest of Asparagus.

Hosts in Britain:

Hosts elsewhere:

Time of year - mines: June-August (Hering, 1957).

Time of year - adults: Unknown.

Distribution in Great Britain and Ireland: Occuring wherever the host plant is regularly cultivated. Oxfordshire (Oxford), Lancaster (Formby), Kent (Godmersham), Surrey (Wisley), Dorset (Chickerell), Hertfordshire (Harpenden), Worcester (Evesham) and Suffolk (Newmarket) (Spencer, 1972: 22).

NBN Grid map:

Distribution elsewhere: Europe (Spencer, 1976: 77) including Germany (Dempewolf, 2001: 79), Denmark, French mainland, Hungary, Italian mainland and Poland (Martinez in Fauna Europaea).

Also recorded in the U.S.A. and eastern Canada (Spencer, 1976: 77).

NBN interactive distribution map(s) of known host species in Great Britain and Ireland and elsewhere:

Parasitoids in Britain and elsewhere: