The weird & wonderful world of Sawfly larvae

01 Thursday Aug 2024

Tags

British sawflies, Caliroa annulipes, Caliroa cerasi, Eriocampa ovata, Euura pavida, Nematus septentrionalis, sawfly larvae

I mentioned earlier in the week, in my post about the sawfly larva Heterarthrus vagans mining the leaves of Alder, that I’d found that miner while checking out leaves to see what small creatures had been munching holes in their leaves. And my recent staring at holey leaves on other trees and shrubs, in other locations, has produced a nice variety of Sawfly larvae, some that look like regular caterpillars, others like slimy slugs. I’ve linked the names to the Sawflies of Britain and Ireland website for those interested in more information on each species.

240801 Caliroa annulipes

Caliroa annulipes on Hawthorn

240801 Caliroa cerasi

Caliroa cerasi, also on Hawthorn

240801 cladius sp

An unidentified Cladius species, on Field rose

240801 eriocampa ovata

The one that looks like bird poo, Eriocampa ovata, on Alder

240801 Euura pavida

One of the bum-waggling species, Euura pavida, on Willow

240801 Nematus septentrionalis

Another bottom waggler, Nematus septentrionalis, on Birch. I love how their munching has created a heart from their leaf.

Nematus septentrionalis

23 Wednesday Aug 2023

Posted by sconzani in insects, trees

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Tags

Birch, British sawflies, Nematus septentrionalis, sawfly eggs, sawfly larvae, sawfly larvae on Birch, sawfly on Birch

The sawfly larvae are back!

You may remember my post last summer (Sawfly larvae on Birch, July 2022) about the black-spotted yellow-and-green larvae of the sawfly Nematus septentrionalis that were munching through the leaves of a local Birch sapling. Well, luckily, the sapling survived but it’s now providing a feast for this year’s brood of the same sawflies.

This time around I’ve found the larvae at a much earlier stage of development. And, destructive though they may be, they do look rather cute curled up in their individual holes in the leaves, and quite different in colour at this young age.

Plus, this time I spotted the eggs they emerged from – and some eggs yet to hatch, laid by the adult sawfly along the veins of the leaves.

I may sound a trifle over-enthusiastic about creatures that are basically eating a tree. But, last year, something ate most of the larvae before they consumed too many leaves and, as there are a good number of hungry Stonechats, Whitethroats, Green- and Goldfinches currently in this field, I think the sawfly larvae’s days are probably numbered.

Sawfly larvae on Birch

09 Saturday Jul 2022

Posted by sconzani in insects, trees

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Tags

British sawflies, larvae eating Birch leaves, Nematus septentrionalis, sawfly larvae, sawfly larvae on Birch

When I spotted these mini-beasties, they were doing a very good job of munching their way through about half the tasty young leaves of a Birch sapling. I knew they were sawfly larvae – that bottom-in-the-air pose is very characteristic of sawfly larvae – and, naturally enough, I assumed they were the Birch sawfly (Cimbex femoratus), but a quick image google showed I was wrong. It took a while to track them down but it seems these are the larvae of Nematus septentrionalis (formerly Craesus septentrionalis).

220709 Nematus septentrionalis

I was rather concerned for the health of the Birch as it is one of a relatively new plantation at the local country park but, when I revisited the site just a few days later, all but a couple of the larvae had disappeared. I don’t think they would have grown to pupation stage that quickly, so I assume a local bird or two had enjoyed them.