Liriomyza orbona (Meigen, 1830)
INTRODUCTION
Unambiguous identification of the European grass mining Liriomyza spp. is very difficult since there are some other very similar species. According to Spencer, 1976 b L. orbona is closely related to Liriomyza richteri Hering, 1927 and Liriomyza infuscata Hering, 1926 which are both described and keyed out in Spencer, 1976 b and shown on Lir infuscata - richteri Sp.pct. Other related species include Liriomyza pedestris Hendel, 1931 (Lir pedestris aedeagus Sp.pct), Liriomyza phryne (Lir phryne aedeagus Sp.pct) and Liriomyza flaveola. The latter two species are treated in the IdentifyIt module. However, the results of identification should be handled very carefully and compared with the differences in the male genitalia of which figures are available here.
(Lir pedestris aedeagus Sp.pct)
(Lir infuscata - richteri Sp.pct)
(Lir orbona aedeagus Sp.pct)
(Lir phryne aedeagus Sp.pct)
(Lir phryne aedeagus.pct)
Further characters
Wing length: 1.7 - 2.6 mm. Aedeagus with amplified filaments. Surstyli present but extremely small.
BIONOMICS
Leaf miner on grasses. Martinez and Chambon, 1983 were the only authors who investigated the life cycle of Liriomyza orbona. They found that the adults are probably present from February to November with peak populations occurring in April/May and in autumn. Under laboratory conditions, the larval stage was completed in 6-14 days. The pupal stage lasted 2-4 weeks. Pupation occurred in the soil.
HOST PLANTS
Triticum aestivum (wheat), Hordeum vulgare (barley) and the wild grasses Lolium perenne and Agrostis stolonifera (Martinez and Chambon, 1983).
DISTRIBUTION
Widespread in Europe.
ECONOMIC IMPORTANCE
So far only one record (Martinez and Chambon, 1983) of economic damage is available. The authors concluded orbona can reduce the yield when the seedlings are infested. A prediction of the pest status of the species is not possible. In the past the species may have been often overlooked, if many leaf-mining species occur simultaneously on one grain. One of these often unidentified species may be sometimes orbona (see Massor et al., 1989).