Mikiola fagi (Hartig, 1839)

Fjellberg, Arne & Fedotova, Zoya, 2024, New records of gall midges (Diptera, Cecidomyiidae) from Norway, Norwegian Journal of Entomology 71, pp. 8-94 : 77-78

Mikiola fagi (Hartig, 1839)

( Figure 45 )

Material: VE, Faerder: Hvasser, Kvieveien , 59.07917°N 10.44670°E ± 10m, 15 September 2022, L, leg. AF, coll. Private; AK , Oslo: Blindern , 59.938941°N 10.720767°E ± 50m, 8 August 2019, L, leg. HE, BOLD : NHMO-ENT-547997, coll. NHMO; 59.938666°N 10.719786°E ± 10m, 12 September 2019, L, leg. HE , coll. NHMO; 59.938453°N 10.720348°E ± 5m, 18 August 2020, L, leg. HE , coll. NHMO; 16 September 2020, L, leg. HE , coll. NHMO; 59.938766°N 10.720454°E ± 5m, 8 September 2020, L, leg. HE , coll. NHMO; 59.938679°N 10.720198°E ± 30m, 23 September 2021, L, leg. HE , coll. NHMO; 59.938941°N 10.720767°E ± 50m, 17 October 2022, LPMF , leg. HE, coll. NHMO.

Biology and notes: The white larvae develop individually in pointed, bottle shaped galls on the upper side of the leaves of Fagus sylvatica ( Fagaceae ). The galls form in early spring, but the larvae do not mature until the fall. In late autumn, the galls detach from the leaves and fall on the

ground, and the larvae pupate and hibernate in the galls. We have tried to hatch this species several times, but we were unsuccessful as long as we brought the hatching cups inside in late winter to force hatching. When the cups were left outside until spring, we succeeded. Hatching then took place in the beginning of April when there was still a good layer of snow on the ground. This species was published new to Norway by Hagen et al. (2012), who in 2012 found it in two undisclosed sites in the Oslo area. At one site (a plant nursery), they found it on imported beeches intended for sale. At the other site (an island), they found it in large numbers on (presumably) planted beeches. The species has since been recorded several places along both sides of the Oslo Fiord, in Rogaland, in Vestlandet and in Møre & Romsdal.

Distribution: Western Palearctic. Widespread in Europe including Norway, Sweden, Denmark and Finland. Although native to Europe, the species has most likely been introduced to Norway with plant import, and it is thus an alien species in Norway.

Figures

FIGURE 45. Mikiola fagi. This species is alien in Norway. A. Leaf galls on Fagus sylvatica. B. Larva extracted from gall. C. Opened gall with pupa. D. Male. Photos: H. Elven.