Stem borer: Larva an internal stem-borer. Pupation internal (Spencer, 1972: 19).

Larva: Details unknown.

Puparium: Posterior spiracular plates adjoining, each with a regular ellipse of 15 bulbs around a strong central horn (Spencer, 1972: 19).

Comments: Spencer (1966a: 21) and Spencer (1972b: 16, 19, 111, 112) misidentifed British specimens of oligophaga as dettmeri, which is only known from Denmark (Spencer, 1990: 394).

The adults are virtually indistinguishable from M. dettmeri (known only on Centaurea jacea from Denmark) with the following essential characters: frons not projecting above eye, orbital setulae in 2 rows, those nearest eye margin reclinate, inner row proclinate; eye with distinct pilosity in both male and female; mesonotum normally faintly greenish; squamae pale, margin pale brown, fringe whitish to ochrous; wing length normally about 3 mm (Spencer, 1990: 394).

Hosts in Britain:

Hosts elsewhere:

Time of year - larvae: Unknown.

Time of year - adults: May. Overwinters as puparium.

Distribution in Great Britain and Ireland: Surrey (Banstead, Betchworth and Walton Heath); Middlesex (Scratch Wood), Cambridge (Chippenham Fen), Derby (Miller's Dale), Denbighshire (Wrexham) and Perth (Killin) (Spencer, 1972: 19 (as dettmeri, see also Spencer, 1990: 394).

NBN Grid map:

Distribution elsewhere: Holland, Germany (Spencer, 1990: 394), Belarus, Germany, Latvia and Lithuania (Martinez in Fauna Europaea).

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

Parasitoids in Britain and elsewhere: Unknown.