Harmandiola tremulae


Harmandiola tremulae is a gall midge whose larvae feed on Aspen causing galls to form on the upperside of the leaves. The galls are globose, 3 to 4 mm across with thick walls, glossy-red when mature but often turning black later.  The opening to the gall is underside, and surrounded by a slightly protruding rim.

Similar Species

Several other species cause spherical galls on Aspen.

Identification difficulty

Gall  Adult


On Aspen (Populus tremulae).

When to see it

The larval stage is from June to September.

Life History

The larva is orange-red.

UK Status

Widespread, though little recorded in Britain. 

VC55 Status

Thought to be fairly frequent in Leicestershire and Rutland.

Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map

Species profile

Species group:
Craneflies, Gnats & Midges
Records on NatureSpot:
First record:
08/07/2011 (Calow, Graham)
Last record:
01/06/2022 (lemmon, roy)

Total records by month

% of records within its species group

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