Sawfly adventures in May (most of, and a bit of April)

My blog remains somewhat sporadic, but this is partly for the good reason that it's because I've been finding lots of sawflies. I'm finding the process of catching, labelling, curating, pinning, identifying somewhat heavy going, but am persevering in the hope it gets easier in due course. Anyway, I haven't left myself much time for blogging, but here's a quick update since last time. I'm including things I've currently identified, although there's lots more (well about 50 more specimens) I've still not sorted out yet.

Sun 29th Apr - found Macrophya alboannulata in the garden (Shotesham), under an elder (the foodplant). Wasn't aware of this "new" (i.e. 1980s!) split, so good to learn about it.

Tues 1st May - Dolerus nigratus netted in Thetford.

Fri 4th May - caught Dolerus nigratus by hand early morning in Shotesham. Later at the Nunnery Lakes in Thetford, found 7 sawflies but to date have only identified Athalia cordata successfully (most of the others are Nematinae which I'm leaving til later in the year).

Sat 5th May - in Shotesham, found Macrophya alboannulata, Dolerus niger, D. nigratus and D. triplicatus. Also went for a hunt around Ashwellthorpe Wood and found 11 sawflies, including Athalia cordata, Nematus lucidus, Claremontia alternipes, Eutomostethus ephippium and Pachyprotasis rapae.

Sun 6th May - in the garden, the rolled rose leaves of Blennocampa phyllocolpa were beginning to be in evidence, and closer inspection lots of the tiny adults were visible around the roses.

Mon 7th May - bank holiday, so we went for an early morning trip to the beach at Covehithe (Suffolk, I know, sorry). I was pleased to find Pamphilius hortorum here, as well as the tiny Hoplocampa chrysorrhoea.

Tue 8th May - back in Thetford, I was surprised to net Strongylogaster multifasciata by the river in an area apparently devoid of ferns, which this species is normally found on.

Wed 9th May - a lunchtime walk at Thetford Nunnery produced Athalia cordata, A. lugens, Dineura stilata and several Hoplocampa crataegi (small sawflies beaten from hawthorn blossom)

Thu 10th May - went over to Shropshire to attend the annual conference of the NFBR (National Forum for Biological Recording). In the evening, we found Dolerus sanguinicollis in the grounds of the FSC's Preston Montford headquarters.

Fri 11th May - still at Preston Montford in Shropshire, in the evening I was shown my first Iris Sawfly Rhadinoceraea micans by Ian Wallace (national caddisfly expert), plus also noted Aglaostigma fulvipes.

Sat 12th May - a small group of us from the conference went on a field trip to Brown Moss in Shropshire. I found several sawflies, and Ryan Clark kindly netted me several more. To date I've identified Dolerus madidus, D asper, Tenthredo colon, Rhogogaster viridis, Birka cinereipes and Apothymus serotinus (the latter as a larva, which I appear to have failed to rear successfully - feeding it the wrong oak perhaps?)

Sun 13th May - back in Norfolk again, lots of Blennocampa phyllocolpa still in the garden, and I found Dolerus picipes elsewhere in the village.

Tue 15th May - at Thetford Nunnery Lakes, my first Eriocampa ovata of the year, plus Dolerus nigratus and D sanguinicollis.

Fri 18th May - a lunchtime walk to the Nunnery Lakes produced the impressive Macrophya annulata plus Hoplocampa crataegi still.

Sat 19th May - spent the day around Shotesham, finding Arge nigripes, Dolerus niger, Aglaostigma fulvipes, Empria alector (I think, would be a new species for Norfolk too), Dolerus vestigialis, Blennocampa phyllocolpa and Macrophya alboannulata.

Sun 20th May - again around Shotesham all day, noting Dolerus nigratus, Ametastegia tenera, Aglaostigma fulvipes and Pontania proxima, the latter in the form of the first galls in leaves of White Willow.

Mon 21st May - lunchtime in Thetford produced Aglaostigma fulvipes, Aglaostigma aucupariae, Pontania proxima (galls) and Dolerus sanguinicollis.

Wed 23rd May- lunchtime in Thetford produced Calameuta pallipes and Athalia lugens.

Thu 24th May - another lunchtime walk to the Nunnery Lakes and I found Tenthredo mesomela and several Athalia circularis; the latter I'm confused about because they're around a patch of Skullcap where I found Athalia scutellariae last year, but these are definitely not that species.

Fri 25th May - again in Thetford, noted a fine Tenthredopsis litterata plus Birka cinereipes and Blennocampa phyllcolpa.

And that takes me up to this weekend, when I've found plenty more around Shotesham and at Surlingham Church Marsh, but mostly not yet identified yet. So that'll do for now.

April sawfly hunting

Spring was a long time coming this year, being cold well into April. I'd had reports of sawflies early in the month from James Emerson, James Symonds and Neil Marks but I didn't get off the ground until 14th April (when Tim Hodge also reported his first, with Nick Elsey the next day). From here on I had quite a good run to 22nd April, then it went cold again. My finds were as follows:

Sat 14th April: Shotesham Common, by sweeping Juncus I found Dolerus varispinus and Pachynematus lichtwardti (I believe).

Tue 17th April: I found four sawflies at Thetford Nunnery Lakes, one netted from a grassy glade (recognised and later confirmed as my first Nematus lucidus), two from sweeping around willow blossom (both Nematinae) and Hoplocampa fulvicornis was swept from blackthorn blossom.

Wed 18th April: afternoon walk on Shotesham Common where I swept three Dolerus spp and one Cladius compressicornis.

Thu 19th April: I popped out to Two Mile Bottom in Thetford Forest at lunchtime, with the express aim of trying to find Xyela julii, and amazingly was successful, sweeping just one from pollen-heavy birch near pines. I also swept two Dolerus, apparently from pine and birch oddly.

Fri 20th April: I swept one Nematinae on Shotesham Common.

Sat 21st April: I visited Lynford Lake in the Brecks and swept four Nematinae and one Hoplocampa chrysorrhoea. I then moved to Foulden Common, finding Nematus lucidus, Hoplocampa fulvicornis and my first ever Pamphilid, this being Pamphilius sylvaticus; also another Nematid and a Dolerus.

Sun 22nd April: Around Shotesham I found Nematus lucidus, another Nematid and a confusing sawfly which seems to key to Hoplocampa but then doesn't seem to fit. Will come back to this.

Then cold on 23rd-25th. Will report on more finds and any further identification successes next time.

P.S. Other species recorded by other recorders so far this year in Norfolk have included Dolerus gonager, Aglaostigma aucupariae and a great record of Acantholyda erythrocephala.

P.P.S. I'm generally not a great blogger, but will try to keep this going reasonably regularly, without promising any nicely polished or well-illustrated articles.

Sawflies to look for in March

After a long winter, and especially after a snowed-in first week of March, I’m looking forward to some warmth. As it’ll be my first spring as county sawfly recorder, I thought I ought to work out which are the first species we should be on the look-out for. So I’ve spent a couple of evenings going through 'Benson' and 'Quinlan & Gauld' {note to self - I’ll need to do a blog post soon on the identification literature}, and tabulating the flight-period information contained therein. That is, in the identification keys where you get to a species, it gives details of range, status, larval food-plants and flight-period, e.g. under Cladius pectinicornis Benson gives ‘V-IX’ (i.e. May to September). It’s half a century out of date, likely to be affected by climate change, range spread and taxonomic revisions (I may well be missing some post-Benson spring species from this article), but it’s the best I’ve got access to. You have to start somewhere.

So, what did I discover? Firstly, no species was listed as being on the wing in January, so that’s good – we didn’t miss anything there. There is one species – Dolerus anthracinus - listed for February, then 14 in March. After that the monthly totals rise sharply, peaking in May and June, before dropping away again quite quickly. Sawflies do seem to be a group that feature most strongly – in their adult form at least – in late spring and early summer.

Rough number of adult sawfly species on wing each month

What to look out for in March then? The 14 species I noted were as follows:

Family Tenthredinidae
[Subfamily Nematinae]

Amauronematus histrio – locally common throughout Britain and Ireland on Willows Salix (incl. cinerea, alba, fragilis). Appears to be unrecorded from Norfolk to date.

Amauronematus leucolenus – locally common in S England, also on willows Salix (incl. cinerea, aurita, repens). Appears to be unrecorded from Norfolk to date.

Amauronematus tunicatus – local in England and Ireland from willows Salix (incl. cinerea, aurita). Appears to be unrecorded from Norfolk to date.

Amauronematus viduatus – another willow Salix species (incl. repens, cinerea, aurita, caprea), locally common throughout Britain and Ireland. We have a previous record from West Harling in March 1990. Included in county checklists by both Bloomfield (1909) and Durrant (2000).

Pristiphora glauca – Benson listed six English and Welsh counties, including Norfolk, with the larval plant listed as larch Larix. Not on any of our county checklists though, so unclear if the latter overlooked the record Benson was referring to, or whether they re-assessed it and found it unverifiable.

Pristiphora pseudocoactula – a rare species in Benson’s time, with records only in Devon, Surrey and Herts. The larvae occur on birch Betula. Not on the Norfolk list.

[Subfamily Selandriinae]

Dolerus madidus – local throughout Britain & Ireland, larvae feeding on rushes Juncus. Bloomfield (1909) listed in his county checklist but Durrant (2000) omitted, so not sure of Norfolk status and perhaps need to look at specimens held in the museum? Featured on Naturespot.

Dolerus anthracinus – larvae on grasses, locally common throughout Britain ("in SE England mainly on chalk grassland"). An old record of this species exists from Wheatfen in 1940. Bridgman (1888) listed for Eaton but Bloomfield (1909) omitted the species, so perhaps had some doubts?

Dolerus coracinus – only known from Aviemore by Benson, larvae unknown.

Dolerus haematodes – widely distributed, larvae on sedges Cyperaceae and grasses Poaceae. Included on county checklists by Bridgman (1888), Bloomfield (1909) and Durrant (2000) but no more recent records yet. Featured on Naturespot.

Dolerus nitens – widespread but rare, larvae presumed on sedges Cyperaceae or grasses Poaceae but undescribed (in Benson’s time at least). Bloomfield (1909) includes on his county checklist but not listed by Durrant (2000). No more recent records. Featured on Naturespot.

[Subfamily Tenthredininae]

Aglaostigma aucupariae - larvae on bedstraws Galium (incl. mollugo,boreale). Very common throughout. We have several records of this species in the county database, including one I found on 26th March 2017 at Caistor St Edmunds Roman fort. Featured on NatureSpot. Important to note there is a similar species A. fulvipes which emerges slightly later, but might well be in a warm March (try to get photos of the side of the abdomen as well as from above).

Family Xyelidae

Xyela julii - a very small species, less than 5mm long. The larvae are in staminate cones of Scots Pine Pinus sylvestris but the adults feed on flowers of other nearby trees, especially birch Betula. Locally common, even abundant, on heaths and widespread in Britain & Ireland. We have a record in the database from West Harling in 1991, and included in county checklists by Bridgman (1888), Bloomfield (1909), Atmore (1914) and Durrant (2000). Featured by Steve Falk who suggests the common name of 'Fairy Sawfly'.

Xyela longula - also occurs on Scots Pine Pinus sylvestris but apparently only recorded in Aviemore.


So, in a Norfolk context, it looks like we should be hunting for 11 species of adult sawflies in March around willows (4 species of Amauronematus), birches (especially on heaths near pines for Xyela), larches (Pristiphora), bedstraws (Aglaostigma) and rushes/sedges/grasses (4 species of Dolerus). That’s enough to be going on with - I wonder if we can find any of them? Let me know if you do.

To reiterate, this is a brief guide to inspire a bit of hunting. If you find something, it won’t necessarily be one of these listed species, but they’d seem like a good place to start. However, please try to get a series of good photos from multiple angles if you can, or even more usefully, get keep a specimen (I suspect this might be particularly important for the Amauronematus and Pristiphora - oh and yes Dolerus too. Basically, most of them!)

Norfolk Sawflies in 2017

Summary

Sawflies are not a well-recorded group at present. I took on the role of Norfolk sawfly recorder in 2017 and have managed to collate a grand total of 176 records for the year, from a variety of sources, involving 79 identified species. Given that there are likely to be about 250 species in the county, and many will be ubiquitous, this suggests we have much to do in establishing the status of this group of insects. However, there’s plenty to discover, which is what makes it exciting.

Of the 176 records, 160 were considered to be acceptable species records, with the other ten being difficult to confirm to species level. Identification (and likewise verification) of sawflies is not easy. The main reason for this is the lack of modern literature; for many species, the most recent published identification guide dates from the early 1950s, although there is a good guide (Wright 1990) that will help you get to genus level. There is further information available online but it is patchy. Although some species can be identified from a good photo, many cannot and need examination under a microscope.

Records were collated from 34 recorders, most of whom submitted single figures of records with the exception of Andy Musgrove (38), Tim Hodge (34), Andy Brown (15), Steve Lane (13) and James Emerson (13). I look forward to seeing these figures rise in years to come! As the map shows, the majority of records originated around Norwich and the Broads, with fewer submitted from West Norfolk.

Norfolk sawfly records in 2017 (thanks to QGIS, Bing maps and the TomBio biological recording plugin)

The first sawfly in 2017 was noted on 18th March, when Dolerus nitens was found. The highest monthly total of records was in May, then records declined steadily, with the last adult sawfly being Athalia rosae on 3rd October, followed by a handful of larval records into November.

A number of species were noted for which there currently appear to be no previous records for Norfolk. This needs to be taken with a pinch of salt, however, since the historical record remains somewhat uncertain due to changes in taxonomy, some recorders not having submitted their previous observations, and the generally very low level of recording. Having said that, Strongylogaster mixta, Hoplocampa fulvicornis, Pachynematus annulatus, Nematus vicinus and Pristiphora testacea do currently represent the first records in the county database for these species.

By far the most frequently recorded species was Athalia rosae, sometimes called the Turnip Sawfly, with 19 records (the only species recorded more than five times). In late May and early June, this species was noted in large numbers on the coast at Salthouse/Kelling and Great Yarmouth. It is unclear whether this represents migration from the continent, and/or very high numbers of home-born insects dispersing and running up against the barrier of the North Sea.

For anyone interested in recording at least one sawfly next year, Athalia rosae is the species to look out for. It is a striking orange and black insect, quite small (6-8 mm from front to back), with a distinctive “football socks” appearance formed by alternating orange and black on the legs. There are a number of similar species; in rosae, the leading edge of the wing is black and the top of the thorax is orange at the front and back, but black on each side. The dark grey larvae can be a pest on cultivated cruciferous plants, including Oil-seed Rape Brassica napus. Other relatively distinctive sawflies for visual identification in the field include Tenthredo scrophulariae (a large black/yellow wasp-like insect with all-orange antennae flying slowly around Figwort Scrophularia) and Eriocampa ovata (a black sawfly with deep red upperside to the thorax found around Alders Alnus, although beware of confusion with the smaller Eutomostethus ephippium where the red extends to the sides of the thorax also). However, perhaps the easiest “evidence” of a sawfly species to come across is the gall of Pontania proxima, which is a red pea-like blister in the leaves of longer-leaved species of Willows Salix.

The best way to submit records is to use iRecord, but I'm willing to take anything, so long as you tell me at least the date and location (with as precise a grid reference as possible). Ideally, tell me the species too, but I'm happy to try to help identify photographs or specimens if I can. Finally, I'm sure there are other Norfolk sawfly records for 2017 out there - I'm more than happy to receive these still (and for earlier years).

Systematic list

Family Cephidae
Calameuta filiformis: Buxton 1/7.
Cephus pygmaeus: Shotesham 23/5; Shotesham 29/5; Sculthorpe 29/5; Norwich 5/6; Norwich 12/6.
Cephus spinipes: Shotesham 23/5; Coltishall 31/5; Shotesham 4/6.

Family Siricidae

Sirex noctilio: Wells East Hills 30/9.
Urocerus gigas: Cringleford Woods 25/6.

Sirex noctilio (Ben Lewis, Matt Stainthorpe)

Family Argidae

Arge berberidis: Breydon Water 17/7; Walcott 22/7; Horsey 23/7; Norwich 7/8.
Arge cyanocrocea: Norwich 21/5; Norwich 27/5; Shotesham 3/6; Holme 22/7.
Arge gracilicornis: Horsey 27/5; Alderfen 15/7.
Arge pagana: Strumpshaw 29/5; Holme 22/7; Whitlingham 12/8; Shotesham 26/8 (larvae on Rosa).

Family Cimbicidae

Abia fasciata: East Winch 28/5; Bowthorpe 21/7.
Abia lonicerae: Norwich 2/4; Salthouse 18/5.
Cimbex connatus: How Hill 28/7; Catfield 24/8.
Cimbex femoratus: Beeston Common 11/5; Knapton 23/5; Beeston Common 31/5 (larva); Acle 31/7 (larva).

Abia lonicerae (James Emerson)

Family Diprionidae

Diprion pini: Catfield 21/9 (larva on Hedera).

Diprion pini (Andy Beaumont)

Family Tenthredinidae

Subfamily Allantinae

Caliroa cerasi: Lingwood 9/7; Waxham 12/9 (both larval records).
Endelomyia aethiops: Horsey 4/5, 8/5.
Ametastegia albipes: Winterton 7/5.
Ametastegia glabrata: Holme 5/6.
Eriocampa ovata: Woodbastwick Fen 29/5; Fairhaven Water Gardens 2/8; Whitlingham 31/8 (larva on Alnus).

Subfamily Athaliinae
Athalia circularis: Shotesham 11/6; Earlham Park 15/7; Horsey 6/8; Great Yarmouth (undated).
Athalia cordata: Holme 5/6, 22/7.
Athalia liberta: Shotesham 13/5.
Athalia rosae: Great Hockham 6/5; Sculthorpe 14/5; Holme 20/5; Cley-Salthouse-Kelling 28/5; Howe 3/6; Thetford 5/6; Great Yarmouth 11/6; Shotesham 11/6; Wheatfen 18/6; Buckenham Carrs 25/6; Lakenham 28/6; Holme 22/7; Salthouse 22/7; Norwich 17/8; Howe 28/8; Horsey 3/10.
Athalia scutellariae: Thetford Nunnery Lakes 14/6 (many around Scutellaria).

Athalia rosae (Steve Mathers)

Subfamily Blennocampinae
Blennocampa phyllocolpa: Strumpshaw Fen 9/7; Shotesham 14/7; Thetford 7/11 (all larval signs on Rosa).
Periclista albida: Whitlingham CP 7/4.
Fenusa dohrnii: Hoveton 6/9 (larval signs on Alnus).
Heterarthrus nemoratus: Hoveton 6/9 (larval signs on Betula).
Metallus lanceolatus: Horsey 9/10 (leaf mine on Geum urbanum).
Profenusa pygmaea: Thickthorn 9/6; Whitlingham CP 7/9 (vacated leaf mine on Quercus)
Eutomostethus ephippium: Swangey Fen 20/5; Horsey 7/6, 8/7.
Eutomostethus luteiventris: Holme 5/6.
Monophadnus pallescens: Holme 5/6.

Phymatocera aterrima: Billingford 17/6 (larva in moth-trap)

Rhadinoceraea micans: Holme 22/4 (many emerging on Iris)
Stethomostus fuliginosus: Thickthorn 14/6.
Haldamia affinis: Horsey 28/4, 1/6.

Phymatocera aterrima (Richard Thomas)

Subfamily Nematinae
Cladius compressicornis: Shotesham 13/5.
Cladius pectinicornis: Great Yarmouth (undated).
Cladius pilicornis: Shotesham 20/5.
Hoplocampa crataegi: Acle 3/5; Wheatfen 5/5.
Hoplocampa fulvicornis: Thetford Nunnery Lakes 6/4.
Craesus septentrionalis: Beeston Common 11/9; How Hill 16/9 (both larval records)
Euura mucronata: Acle 3/5.
Nematus vicinus: Wheatfen 5/5.
Nematus myosotidis: Shotesham 17/6.
Pachynematus annulatus: Shotesham 23/5.
Pontania pedunculi: Holme 22/7
Pontania proxima: Thetford 15/6 (galls in Salix); Shotesham 14/7 (galls in Salix); Buxton 6/9 (galls in Salix).
Pristiphora brevis: Roydon Fen 23/6.
Pristiphora testacea: Tasburgh 16/7 (larvae on Betula).

Craesus septentrionalis (James Emerson)

Pristiphora testacea (Mike Dawson)

Subfamily Selandriinae
Dolerus ferrugatus: Holme 1/5.
Dolerus triplicatus: Holme 1/5; Shotesham 13/5.
Dolerus vestigialis: Frogshall 15/4; Wheatfen 5/5.
Dolerus aericeps: Thickthorn 11/5; Buckenham Carrs 25/6; Shotesham 9/7; Sea Palling 20/8.
Dolerus aeneus: Buckenham Carrs 25/6.
Dolerus niger: Thetford 15/6.
Dolerus nigratus: Holme 1/5; Shotesham 14/5; Ongar Hill 1/6.
Dolerus nitens: Barney Wood 18/3.
Dolerus picipes: Thetford Nunnery Lakes 6/4; Shotesham 13/5.
Strongylogaster mixta: Bilney Warren 28/4.
Strongylogaster multifasciata: Beeston Common 16/5; Beeston Common 2/6.

Subfamily Tenthredininae
Macrophya duodecimpunctata: Norwich 27/5; Nunnery Lakes 14/6.
Macrophya montana: Coltishall 31/5; Norwich 3/6; Bodham 24/6; Alderfen 15/7.
Macrophya punctumalbum: Thickthorn 14/6.
Aglaostigma aucupariae: Caistor St Edmunds 26/4; Shotesham 1/4.
Aglaostigma fulvipes: Surlingham Church Marsh 15/4.
Tenthredopsis nassata: Shotesham 23/5.
Rhogogaster chlorosoma: Ringstead Downs 12/6.
Rhogogaster viridis: Thickthorn 9/6; Wheatfen 18/6.
Tenthredo amoena: Norwich 18/7.

Tenthredo arcuata: Coltishall 31/5; Pigney’s Wood 4/8.
Tenthredo colon: Bracon Ash 12/8 (larvae on Circaea lutetiana)
Tenthredo mesomela: Shotesham 23/5; Horsey 27/5; Sculthorpe 28/5.
Tenthredo notha: Holme 22/7; Pigney's Wood 4/8.
Tenthredo omissa: Holme 12/8, 13/8; Ludham 20/8.
Tenthredo schaefferi: Horsey 23/7; Little Hautbois 10/8.
Tenthredo scrophulariae: Stoke Holy Cross 7/6; Beeston Common 19/7; Holme Dunes 20/8.

Macrophya montana (Vanna Bartlett)

Tenthredo amoena (Vanna Bartlett)

Tenthredo scrophulariae (Nick Elsey)

Contributors in 2017:

Iain Barr, Vanna Bartlett, Jeremy Bartlett, Andy Beaumont, Andy Brown, Dave Buckingham, Bex Cartwright, Mark Clements, Richard Comont, John Crann, Mike Dawson, Nick Elsey, James Emerson, Francis Farrow, Tim Fawcett, John Furse, Martin Greenland, Gary Hibberd, Tim Hodge,  Michael Hoit, Tony Irwin, Robin Jeffries, Steve Lane, Ben Lewis, Neil Marks, Steve Mathers, Andy Musgrove, Adam Parker, Rob Smith, Matt Stainthorpe, Emily Swann, Richard Thomas, Matthew Wilkinson, Robert Yaxley

Note: this summary was originally written in February 2018. The article was updated in September 2018 following collation of further information.