Agromyza albipennis Meigen, 1830
This species can be confused with Agromyza nigripes Meigen, 1830 and Agromyza graminicola Hendel, 1931 which share all external and larval characters.
IMPORTANT CHARACTERS
Adults
Wing length: 2 - 3 mm. The three inwards directed apical frontorbital bristles are smaller and thinner than the dorsal ones. Third antennal segment of characteristic shape (Spencer, 1973 Ag albipennis ant Sp.pct). Three strong postsutural dc, additionally one or two small hair-like bristles can be found anteriorly. Squamal fringe white. Abdominal tergites and mesonotum shining, covered in very fine pubescence, mesonotum black somewhat metallic, abdomen rather brown.
Male terminalia
According to Spencer, 1973 entirely distinctive. Ag albipennis aedeagus Sp.pct, Ag albipennis aedeagus.pct, Ag albipennis genitalia.pct.
Immature stages
Larval mandibles of the same length. Posterior spiracle with three openings and minute spiracular hairs (A albipennis Larva3 SEM.pct, only visible at high magnification). Intermediate sclerite on the ventral side distinctly bent downwards. (Other figures in the 'multimedia' tab)
BIONOMICS
The larvae form rather large blotch mines on grass leaves. The feeding activity inside the leaf normally affects all cell layers, even if they are not consumed completely. The puparia are normally near the mine, glued on a leaf of the host plant. Sometimes the larva does not leave the mine for pupation. This behaviour is atypical for Agromyza species and the reason might be that the preferred host plant, Phalaris arundinacea, mainly occurs in moist areas. The puparia most probably cannot survive in temporarily inundated soil.
In Europe, there are several generations between June and October.
HOST PLANTS
Europe: The wild grass Phalaris arundinacea seems to be the preferred host plant, other host plants are Hordeum vulgare L. (barley). Secale cereale L. (rye). and wild grasses of the genus Poa.
Japan: Hordeum hexastichon L., Oryza sativa L. (rice), Secale cereale, Triticum aestivum L. (wheat). and wild grasses of the genera Agropyron and Phleum.
DISTRIBUTION
Holarctic.
Remark: In Japan and China the behaviour and host range is quite different, there may in fact occur a sibling species.
ECONOMIC IMPORTANCE
Only from Japan, the species is known as serious pest of wheat and barley (Spencer, 1973).