Cimbex connatus


A very large (3 cm body length) sawfly, vaguely resembling a hornet but fatter bodied. The larvae are up to 50mm, yellow/green with blue dots along the sides and large dorsal stripe.

Identification difficulty

Around alder species, sometimes Italian Alder planted in city centres and supermarket car parks.

When to see it

Mid to late summer.

Life History

The larvae feed on various alder species. When fully grown, they are about 50 mm long and have a dark dorsal stripe all the way along the body. They generally feed between July and September, but may still be found as late as October.

UK Status

Uncommon but expanding its range.

VC55 Status

Rare in Leicestershire and Rutland (VC55).

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Leicestershire & Rutland Map


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

UK Map