* Xylodiplosis nigritarsis (Zetterstedt, 1850)

(Figure 23)

Material: VE, Faerder: Mågerølia, 59.15097°N 10.43579°E ± 50m, 25 July 2019, ovipositing on Quercus sp. stump, F, leg. AF, coll. NHMO; Mågerø, Ødegården, 59.14901°N 10.42712°E ± 50m, 15 August 2019, Ovipositing on Quercus sp. stump, F, leg. AF, coll. NHMO ; Mågerø, 59.15217°N 10.43257°E ± 10, 16 August 2019, Ovipositing on Quercus robur stump, F, leg. AF, coll. Private ; Larvik: Rakke, 58.98286°N 10.02129°E ± 10m, 27 October 2022, Larvae leaving Quercus robur xylem, L, leg. AF, coll. Private.

Biology and notes: The very slender, yellowish white larvae develop in the xylem vessels of freshly cut stumps of Fraxinus excelsior ( Oleaceae) and Quercus spp. ( Fagaceae). Studies done in southern Norway indicate that the females hatch in May and seek out fresly cut trees to oviposit in the exposed vessel openings. The larvae develop over some 4–5 weeks before leaving the xylem, usually during a rainy period, to pupate in the ground. Several generations per year with ovipositing stretching into late autumn. The species was identified by the dark colour of the tarsi as well as the colour of the larvae.

Distribution: Known from a few European countries including Norway, Denmark and Finland.