Macrolabis fagicola Barnes, 1939

Fjellberg, Arne & Fedotova, Zoya, 2024, New records of gall midges (Diptera, Cecidomyiidae) from Norway, Norwegian Journal of Entomology 71, pp. 8-94 : 74-75

* Macrolabis fagicola Barnes, 1939

( Figure 43 )

Material: AK, Oslo: Blindern , 59.939755°N 10.718249°E ± 10m, 27 August 2019, M, leg . HE, BOLD: NHMO-ENT-548004,548209, coll. NHMO; 59.938950°N 10.720803°E ± 40m, 15 August 2022, LMF, leg . HE, coll. NHMO; Sagene ,

Nordre gravlund, 59.936448°N 10.745104°E ± 80m, 15 August 2022, 5L1F, leg. HE , coll. NHMO.

Biology and notes: The larvae live as inquilines in the shoot galls of Contarinia fagi on Fagus sylvatica ( Fagaceae ). Bi- or multivoltine; pupation and hibernation in the soil. We collected larvae in the autumn, and some proceeded to hatch the same year without diapause, whereas others hibernated and hatched in the spring. The color of the larvae has not previously been described, but our larvae were pale pink to orange, reddening towards the ends ( Figure 43 B ). The larvae were furthermore broad and very dull due to dense microsculpture. This species nested far from other Macrolabis in our barcode tree, grouping instead with Dasineura . Already in the original description, Barnes (1939) pointed out that this species has traits connecting it to both Macrolabis and Dasineura . The adult males have the enlarged gonocoxites typical of Macrolabis , but the flagellomeres in the male antennae have short but distinct necks, a trait found in a.o. Dasineura but not in Macrolabis . Barnes (1939) himself tentatively placed the species in Dasineura . Möhn (1961) later erected a new genus for it, Schueziella Möhn, 1961 , and proposed that it stood close to Macrolabis . Gagné (2004) subsequently synonymized Schueziella with Macrolabis . Although our barcode tree does not constitute a rigid phylogeny, it lends support to Barnes’ original suspicion that this species belongs in Dasineura .

Distribution: Known from several European countries including Norway, Sweden and Denmark.

Figures

FIGURE 43. Macrolabis fagicola. This species is an inquiline in the galls of Contarinia fagi on Fagus sylvatica. It is currently placed in the genus Macrolabis, but our DNA barcoding indicates a placement in Dasineura. A. Larvae in the gall of the host. B. Larva. C. Male. D. Female. Photos: H. Elven.