Portevinia maculata (Fallén, 1817)

Identification

Identification difficulty = 1. eyeball_icon camera_filled_icon according to Ball & Morris, 20241

Synonymy

Cheilosia maculata Fallén in Coe(1953)2.

Biology

The larva tunnels in the bulbs of Ramsons Allium ursinum. During its short flight period, males are often abundant around stands of the larval food plant, where they can be seen visiting the flowers and resting on the foliage. Females generally fly low down amongst the plants and are more difficult to find.

Flight period

The following plots show the number of unique records per week excluding those reported to be of immature stages. Phenology plots for Portevinia maculata

Distribution

Although very widely distributed, this species is most frequently found in more heavily wooded regions. Current data suggest that cooler regions are preferred and the comparative lack of records from the south and east where recorder effort is highest may be indicative of this. Woodlands in the Pennines and southern Scotland are exceptionally suitable. Distribution map for Portevinia maculata

Trends

The following plots show the Frescalo TFactor vs year and a map of the rescaled frequency (all records) for the species.Trend plots for Portevinia maculata

  1. Ball, S., & Morris, R. (2024). Hoverflies of Britain and Ireland. WILDGuides (3rd ed.). Oxford: Princeton University Press. ↩

  2. Coe, R. (1953). Diptera: Syrphidae. Handbooks for the Identification of British Insects, 10(1), 1–98. ↩