Chalcosyrphus eunotus

Alternative names
Logjammer Hoverfly

A medium-sized, brownish hoverfly superficially resembling Brachypalpus laphriformis, but the thorax is dull with faint stripes and the abdomen is broader with pairs of narrowly separated squarish grey patches on tergite 2 (male) and tergites 2 and 3 (female). It is much larger than C. nemorum and with much hairier legs, but the two species often occur together, so care is necessary.

Identification difficulty
Recording advice

Good quality images are required showing the identifying features. It may not be possible to confirm some records without suitable images.


Adults can be observed resting on fallen timber at the edge of streams, on log jams, or sunbathing on nearby foliage. Males are territorial and will attack passing insects. Adults rarely visit flowers.

When to see it

Adults fly from April to July but seem to peak in late April and early May.

Life History

The larvae develop in partially submerged fallen logs and branches in streams, especially where log jams have formed. This is nearly always in wooded streams with dappled sunlight and lush streamside vegetation (e.g. Stinging Nettle or Butterbur beds).

UK Status

Chalcosyrphus eunotus is scarce but possibly under-recorded with records confined to southern Britain especially the West Midlands and Welsh Marches. Graded Nationally Scarce by Ball & Morris (2014, JNCC Species Status No. 9).

VC55 Status

Rarely recorded 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:
Records on NatureSpot:
First record:
22/04/2023 (Pochin, Christine)
Last record:
22/04/2023 (Pochin, Christine)

Total records by month

% of records within its species group

10km squares with records

The latest images and records displayed below include those awaiting verification checks so we cannot guarantee that every identification is correct. Once accepted, the record displays a green tick.

In the Latest Records section, click on the header to sort A-Z, and again to sort Z-A. Use the header boxes to filter the list.

Latest images

Latest records