Contarinia petioli (Kieffer, 1898)

Material: AAY, Tvedestrand: Askerøya, Kibbevik, 58.610887°N 9.077196°E ± 4m, 19 June 2021, L, leg. HE, coll. NHMO; TEI, Seljord: Blika, 59.5914013°N 8.5615844°E ± 100m, 18 June 2019, L, leg. SH, BOLD: NHMO-ENT-548107, coll. NHMO; AK, Asker: Brønnøya, Pilbogen plot 41/177, 59.853934°N 10.527666°E ± 3m, 31 May 2020, L, leg. HE & TS, coll. NHMO; Oslo: Ellingsrud, 59.932221°N 10.906987°E ± 6m, 6 June 2021, L, leg. HE, coll. NHMO; 59.936680°N 10.920363°E ± 50m, 17 June 2022, L, leg. HE, coll. NHMO; 59.929600°N 10.913064°E ± 200m, 19 June 2022, LM, leg. HE, coll. NHMO; Nannestad: Aurmoen, 60.243180°N 11.098261°E ± 500m, 7 July 2020, L, leg. HE & TS, coll. NHMO; TRI, Storfjord: Skibotndalen, Lullefjellet, 69.303553°N 20.440693°E ± 700m, 4 July 2019, L, leg. HE, coll. NHMO.

Biology: The bright orange larvae develop in roundish galls on the petioles and leaf bases of Populus tremula, rarely also on other Populus species ( Salicaceae). Our records are all from Populus tremula . Each gall may contain a single or several larvae, each in a separate chamber. Univoltine; pupation and hibernation in the soil.

Distribution: Widespread Palearctic, including Norway, Sweden, Denmark and Finland.