Found sunning itself on Ground Ivy. Help needed with identification.
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Zaraea lonicerae is a sawfly from this family that looks very similar, but I don't know enough to say if it's that species or even genus. Hopefully someone else will be able to be a little more definitive.
Good shot! If you have rough grassland with scabious growing nearby this would be another clue - the grubs feed on scabious.
PS - you've stated it's on Ground Ivy - it's just regular common Ivy (Hedera helix) growing along the ground. Ground Ivy is Glechoma hederacea and has a different leaf shape and mauve flowers:
What are the key features that identify this as Abia sericea? (Wouldn't the ones mentioned also match Zaraea lonicerae?) I don't have much experience with sawflies and couldn't see a clear way to get this photo to species with the RES key so any tips would be useful. (Is there a better reference or website out there?)
I find the Abia/Zaraea sawflies very tricky to sort out, not helped by the fact that the species we now call Zaraea are often put in genus Abia elsewhere. Also, I haven't seen very many of either genus, so am not sure how variable they are.
In theory Zaraea have black antennae while Abia have at least some yellowish/reddish markings on the antennae, although I think this can vary a bit. There are also differences between the sexes, which have rather different abdominal shapes (I think this one is a female).
My feeling is that this is Zaraea lonicera, partly because of the black antennae, and partly because of the location. Z. lonicerae feeds on honeysuckle (and snowberry) and I have found it in gardens before, whereas Abia sericea feeds on knapweeds and scabiouses and I've only ever seen it on nature reserves. I think Abia usually has a bit more contrast between the abdomen colour and the thorax colour.
There is another Zaraea species, Z. aenea, that is similar to Z. lonicerae, but it has only ever been recorded once in Britain as far as I know.
Entomologist and biological recorder
Many thanks for taking the time to explain the difficulties of ID'ing these Martin. I've only ever caught brief glimpses of sawflies in this family and never managed to photograph one, but it is very useful to know what to look for in the future.
Thanks for all the comments.
For interest, my small garden has quite a few Knapweeds in a wild area of rough grassland. Honeysuckles are also present.
I used to have quite a few of the cultivated type of Scabious sold in garden centres but these have all now died.
I have three Chinery books, and two mention only Abia sericea. None mention Zaraea lonicera (Z.fasciata in one). They do say the antennae is usually entirely reddish brown or orange, sometimes blackish. The female is less common with a purple thorax.
The Chinery books are fantastic for getting somewhere close to an insect identification, and are very helpful in helping get to the correct family or even genus, but inevitably they can only include a small proportion of the 30,000+ UK insect species. Always worth checking an ID from Chinery against a more complete specialist publication, or on iSpot of course!
I'd be really interested to know from some of the people who agreed with Abia sericea why they think it is that rather than Zaraea lonicerae! I'm still of the opinion that it's a better match for Zaraea, but I'm happy to be proved wrong, would just like to know why!
On the subject of the plant in your photo, the plant is ivy (on the ground), not Ground Ivy. You probably realise this. The former is Hedera helix, the latter is Glechoma hederacea.
University of Edinburgh and Biodiversity Observatory (OU)
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