Danish scientist records 45 gall midge species in Estonia

A Danish scientist recorded 45 gall midge species not previously documented in Estonia during a week of fieldwork, ERR reports. The findings form part of the first study of Estonia’s plant-feeding gall midges.

Hans Henrik Bruun, a professor in the Department of Biology at the University of Copenhagen, visited 18 locations in Estonia in late August last year at the invitation of University of Tartu researchers Kadri Runnel and Asko Lõhmus. He surveyed alvars, wooded meadows, coastal meadows, floodplains, swamp forests and urban areas, from Lääne-Nigula to Saaremaa and Muhu, and from Soomaa and Tartu to Põlva and Räni.

Before the study, 152 gall midge species had been recorded in Estonia, largely through the Estonian Malaise trap project. None belonged to Cecidomyiinae, a subfamily consisting mainly of plant-feeding species that had not previously been studied in the country.

Combining Bruun’s findings with reliable records from citizen-science portals such as eElurikkus and the GBIF database, the researchers compiled a preliminary list of 70 species for Estonia. Two could be identified only to genus. Eight of the species Bruun found, including Dasineura myosotidis, Geocrypta braueri and Semudobia skuhravae, had not been recorded in any of Estonia’s three neighbouring regions: Latvia, Finland or Leningrad Oblast.

Gall midges are small flies, usually only a few millimetres long. The larvae of plant-feeding species develop in galls, which are often fleshy or woody growths on host plants and provide both food and shelter. Most species are highly specialised, using a particular host plant and plant part. Researchers can often identify them by the shape of the gall and the characteristics of the larva.