Mothing Update

I've finally caught up on editing photos and Peter H has very kindly completed a batch of gen dets for me, so I can do an update on some mothing highlights around Oxford for me this year so far. 

Elachistids 

I got quite into looking for Elachistid mines last spring, and continued with it this spring too. I found most of the same ones as last year and a few extras. 

Elachista adscitella and Elachista humilis were both frequently encountered in March and April, both mining Tufted Hair Grass, a relatively easy grass to ID (fortunately for me), mostly where it was growing under beech trees on the chalk (but that was mostly where I saw the plant). I found them at Wytham Woods and in a number of woods on the Chilterns while failing to find Coleophora antennariella near Stoke Row. This moth is only known from this area in the UK where it was seen by Waters in the 1920s. I am the latest of a number of people who have failed to find it since (!), planning to look for larval cases on Hairy Wood Rush, but actually failing to find enough of the plant to really search properly, despite visiting quite a few woods. Happy to provide info on where I searched if others want a go!

Elachista adscitella mine at the tip of  a Tufted Hair Grass leaf - Wytham Woods.

Also found in 2021 and found again this spring were: Elachista poae - frequent on Reed Sweet Grass at Marston Meadows and Wolvercote Green and Elachista obliquella, on False Brome at Aston Rowant where it was the 3rd VC23 record. This species makes a fairly broad brownish mine in spring, which I found in good numbers here where the foodplant grew in isolated tussocks under the shade of beech trees.

Elachista obliquella mine on False Brome - Aston Rowant NNR

And then some new ones this spring: Elachista stabilella, on Tall Fescue in the winter, at Marston Meadows and Iffley Meadows. This makes a very slim, subtle mine, but was quite frequent at Marston Meadows, with some tussocks having several mines.

A young Elachista stabilella larva in a slim mine on Tall Fescue - Marston Meadows

Elachista stabilella reared from a mine on Tall Fescue

Elachista utonella, on Greater Pond Sedge at Otmoor MOD and Chilswell Valley. This species is a bit of a wetland specialist and isn't seen too often. I have seen the adults in large numbers flying around Greater Pond Sedge on July evenings, and it seems the mines (broad whitish ones about halfway up the leaf) are relatively easy to find too, I found about a dozen in 5 minutes or so at Chilswell Valley.

Elachista utonella mine on Greater Pond Sedge - Chilswell Valley. The larvae start off yellowish and turn grey as they grow.

An adult Elachista utonella, reared from the mine on Greater Pond Sedge, Chilswell Valley.

Also on Pond Sedge, at Cothill Fen, I found a few of the very subtle mines of Elachista alpinella, thin and brown, running down from a central leaf into the base of the plant. It looks like this is about the 4th record for VC22.

The long, slim mine of Elachista alpinella, down into the base of a pond sedge plant.

And two that I see often as adults but were nice to see as larvae - Elachista argentella (Wytham Woods, on Tor Grass) and Elachista canapennella at Aston Rowant (on Meadow Oat Grass). The latter is so common in traps but doesn't seem to be that easy to find as a mine, perhaps because it has so many possible foodplants!

Common, but nice to see - the mine of Elachista canapennella on Meadow Oat Grass at Aston Rowant.

Leafminers

I've also seen a few more conventional leafminers, though the season for this is really about to kick off. Back in the winter I found Phyllonorycter ulicicolella at Burnham Beeches where it was new for Buckinghamshire (Dave tells me), and found lots of mines at Bagley and Wytham Woods again this spring. Also at Wytham I found lots of old mines of Cosmopterix scribaiella on fallen reed leaves in late March. Bringing these indoors produced lots of the stunning adults after a month, and amazingly no parasitoids - it seems it's currently outrunning them as it rapidly expands its range! Richard Homan and I both found mines in VC23 last autumn, the first records for Oxfordshire.

Cosmopterix scribaiella - ex mine on Common Reed at Wytham Woods

At Aston Rowant in late May I also found a few mines of Eriocrania sparmannella (differentiated from salopiella on the basis of the larva) on birch. Surprisingly this seems to be new for Oxfordshire.

Eriocrania sparmannella mine - Aston Rowant

Coleophorids

Of the Coleophorids I found this spring, the highlight was definitely Coleophora sylvaticella at Bagley Woods. Marc Botham caught an adult here in 2020, which I think was the first for VC22, and I had a look for Great Wood Rush to try and find larvae last summer, as this is meant to be its only foodplant in the UK. I did not succeed in finding any, but this spring found a big patch of Hairy Wood Rush not far from where Marc had caught his adult. I got stuck in looking for Elachista mines on this, and was amazed to find what looked to be several Coleophora sylvaticella larval cases fixed for pupation on the lower leaves (in early March). A return visit in early April produced many more (when more had presumably emerged from hibernation), and I was able to rear adults from these which Peter dissected, confirming that they were sylvaticella despite the unusual foodplant. I think this might be the first time this species has been reared from Hairy Wood Rush, but probably need to check the books more carefully than I have to be sure. Yesterday I visited again and found them feeding on the seeds of the plant too.

Coleophora sylvaticella larval case - Bagley Woods

If you look closely you should be able to see 4 cases of Coleophora sylvaticella fixed for pupation on the lower leaves of the Hairy Wood Rush plant in the centre of this image.

Adult Coleophora sylvaticella, bred from cases at Bagley Woods.

Like Dave W I also found Coleophora solitariella on Greater Stitchwort this spring, at Bagley Woods and Shotover Country Park. Other interesting ones were Coleophora albicosta on Gorse (Wytham Woods, Bagley Woods, Hitchcopse Pit), Coleophora albitarsella (Aston Rowant) and Coleophora lixella (Aston Rowant). It was nice to see the latter in spring, feeding on grass, as I've only previously seen it in the autumn when it feeds on Thyme seed capsules.

Plumes

The same visit to Aston Rowant also produced a number of nice plume larvae, Mugwort and Thyme (on Mugwort and Thyme respecitvely!), Citron and Dusky (in rosettes of Ploughman's Spikenard), and Dingy White (on Marjoram). All of these species have quite obvious feeding signs (apart from maybe Thyme, which feeds openly on the leaves) and are worth looking for anywhere on the chalk.

Gelechiids

Another spring highlight was finding the mines of Monochroa arundinetella at Marston Meadows and Wolvercote Green. This is a rather mysterious species with few recent UK records, particularly of the larva. In fact, I think the last one may have been by Phil Sterling at the same site (Marston Meadows) from which he provided the description that is in the Field Guide to Smaller Moths now (also the last Oxfordshire record). I found them mining Greater Pond Sedge which is a very common plant in wet places by the Thames round here, so it's probably very overlooked. The mines I found were quite subtle - brownish smudges that are very wiggly with lots of diverticula, about halfway up a leaf. These seemed to be the ones larvae form in autumn and overwinter in, before they extend the mine in a much straighter way down to the base of the leaf.

A Monochroa arundinetella mine in the field - the brownish smudge on the Greater Pond Sedge leaf running across the picture.

The same mine up close - a wiggly brown overwintering mine.

A Monochroa arundinetella mine after the larva has started feeding in the spring - the old (brownish) overwintering mine is on the right and the larva has extended it straight downwards towards the base of the leaf.

Monochroa arundinetella larva

Tortricids

Two tortrix highlights for me, the first was a male of Pammene agnotana (gen det thanks to Peter H), a mysterious hawthorn feeder whose larval stages are not well known and didn't have many UK records until this spring when quite a few people got it to the FUN lure when they put it out near old Hawthorns. I got mine like this, with a pheromone trap set on a sunny afternoon in mid April at Aston Rowant, where there are lots of old hawthorns. It seems to be the first VC23 record.

Pammene agonotana - to FUN lure, Bald Hill, Aston Rowant.

The other excitement came in June, with what I think is a new colony of Grapholita pallifrontana, on a small patch of Wild Licquorice growing by the sliproad for the A34 (northbound) at Botley interchange. On the same day I also found it at Wytham Woods, on Rough Common, where there is quite a lot of foodplant (though suffering somewhat from sheep grazing) and I think a rather old record of the moth already.

Others

Of the other stuff Moitrelia obductella seems to have turned up in quite a few places over the hot weather in the last few weeks, and I was pleased to find larvae on Marjoram at Aston Rowant in late May too. They make a very distinctive messy spinning in the shoot that is quite obvious, I found 4 in about a half hour of searching, so not too hard to find. I reared an adult to confirm the ID, and what I think is the first record for Oxfordshire of this rapidly expanding species.

2 Moitrelia obductella larval spinnings side by side on Marjoram at Aston Rowant

The larva inside - takes quite a bit of digging to get through the dense spinning.

Dave already mentioned we found Tinagma oncerostomella at Arncott MOD, where it was new for Bucks. I've also been seeing it in VC22 down at Cothill. I found larvae in the winter at Hitchcopse Pit and in a field near Frilford Heath, which were the 2nd and 3rd VC22 records, and then saw the adult in the same places in June (and another field margin nearby). This species feeds on Viper's Bugloss, and can be found as a larva overwintering in the stems. At both sites I found larvae in the first stem I opened up, and adults were super abundant in June, giving almost any plant a cursory tap with a net handle would flush a few. Basically it seems to be very easy to find where it occurs (but very under-recorded) so if you have any Viper's Bugloss near you, do keep an eye out!

Tinagma oncerostomella - Arncott MOD

Dave also mentioned that we didn't manage to find any of the larvae of the interesting Dyer's Greenweed feeding micro moths at Arncott, but they did at least seem to be having a good year elsewhere. Densities of the gelechiid Mirificarma lentiginosella were extremely high at Wendlebury Meads - I found them on 29/30 plants I checked, and one plant had 22 larvae on! Sadly I didn't find Agonopterix atomella there, but it was present in good numbers at Otmoor MOD in early June when I visited with Nick Bowles, and seems to have had a good year across all the sites regularly surveyed by Butterfly Conservation, good news for this rare moth!

A young Agonopterix atomella larva peeking out of its spinning on Dyer's Greenweed at Otmoor MOD