Hammerschmidtia

Males have a tuberculate face with long hairs on the arista, most hairs several times longer than the arista itself. Scutum bears prominent spines; anepisternum, postalar callus, and scutellum have strong bristles. Abdomen twice as long as thorax. Wing with first posterior cell not ending acutely; apical section of R4+5 longer than crossvein r-m; upper marginal crossvein M1 curved inwards where it meets R4+5. Legs with spines; anterior four tibiae terminate in a row of bristles. Femora swollen, especially hind pair with conspicuous ventral spines.

Decaying wood of freshly fallen trees, particularly aspen (Populus tremula). Breeding habitat is limited and transient, requiring specific decay stages of dead wood.

Holarctic. Records from Denmark, Norway, Sweden. In the UK, restricted to fragmented populations in Scottish aspen woodlands.

• Populus tremula - breeding substratelarvae develop in decaying aspen wood

Larvae develop in sap under bark of freshly fallen trees. Adults emerge from decaying logs.

Males of H. ferruginea exhibit territorial behavior at decaying aspen logs, with territories overlapping female oviposition sites. Dispersal up to 5 km recorded, though 68% of individuals disperse ≤1 km. Male wing length positively associated with dispersal distance.

H. ferruginea is endangered in the UK, prompting conservation efforts including aspen expansion across Scotland and retention of dead wood.

• Other Brachyopini generashare swollen femora and spiny leg characteristics; distinguished by male facial tubercle, arista hair length, and specific wing venation patterns

• hoverfly
• saproxylic
• aspen
• dead wood
• territorial behavior
• Holarctic

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Mark recapture estimates of dispersal ability and observations on the territorial behaviour of the rare hoverfly, Hammerschmidtia ferruginea (Diptera, Syrphidae)