Last modified: Dec. 25, 2023, 1:12 p.m.
A very rare and local species in the southern part of Belgium. Not seen for a very long time, presumably extinct.
Native
Wingspan 12–16 mm. The front wings are ash grey, sometimes with a brown tinge. The front edge of the wing is lightened at half its length, this lightening is interspersed with thin, slightly longitudinal lines with a golden sheen. The outer field is dotted with silvery scales.
The larva is monochromatic whitish with a pale brown head.
Occupied stems are easy to identify because the larva cuts the upper part of the stem and closes the standing part of it with a frass plug through which the pupa later extrudes. Feeding starts from the base of a petioles and then larvae pierce downward inside the stem to the root. The stem is filled with frass inside, but the last 4-10 centimeters are left hollow. Pupation in the lowest part of the stem in a pupation chamber closed at both ends by frass plugs.
The adults are active in sunshine and later come to light.
The adults are on the wing from May to early July.
The larva feeds mainly on Ononis spinosa and very likely on Onobrychis viciifolia and Trifolium medium.
It favours grassland on chalky soil and inhabits open fields, flowery meadows and open places.
