Agromyza intermittens (Becker, 1907)
DIAGNOSIS AND DISCUSSION
Wing length: 1.9 - 2.75 mm.
Although this species is a grass miner, it does not belong to the nigripes-group, which most of the Agromyza grass miners belong to. The peculiar shape of the long aedeagus indicates close relationship with Agromyza luteitarsis and Agromyza cinerascens. Distinguishing these species is not easy and also their scientific justification needs further investigations. According to Spencer, 1976 b, intermittens can be distinguished from cinerascens by the reddish frons (darker, brown in cinerascens). Furthermore the acrostichals in intermittens are less dense (2-3 rows) than in cinerascens (about four rows).
Characters to separate A. luteitarsis from intermittens were reported by d'Aguilar et al., 1976: A. luteitarsis has generally a smaller size and a fully developed crossvein m2 (normally vestigial or missing in intermittens). The puparia also show some differences which were also discovered by d'Aguilar et al., 1976. Primarily the anterior part is darkened in luteitarsis, while the whole puparium is uniformly colored in intermittens.
HOST PLANTS
Cereals: Hordeum vulgare (Winter barley and spring barley) Secale cereale L. (rye), Triticum aestivum L. (wheat). Most probably many wild grasses are also infested.
BIONOMICS
Usually only one generation in spring, sometimes a second one may appear.
DISTRIBUTION
Widespread throughout the palaearctic region, recorded from Tunis to Japan. (Macedonia, France, Germany)
ECONOMIC IMPORTANCE
This species is one out of several Agromyza species frequently occurring on cereals. Together with other species A. intermittens can cause serious damage.