Gymnancyla canella

A rare species but easy to find if it's present. The larva feeds on Prickly Saltwort Salsola kali and is reputed to be the only species to do so, although there are bound to be some polyphagous species that will use it occasionally. The larva feeds initially in the stem or a side shoot but later may feed externally in a web which is made conspicuous by the sand grains that become trapped in it.

                                                                        Larval web

Ectoedemia albifasciella

There are four species of Ectoedemia which mine the leaves of deciduous oak but this is the only one around at the moment (many will already be vacated). If the larva is still present it has a pale head.

The mine typically starts as a narrow linear gallery that follows a vein and is later absorbed into the blotch but the linear frass can still be seen. The gallery occasionally doesn't follow a vein as can be seen on two of the mines in the leaf below.

Stigmella plagicolella

It seems to be an awful autumn for Nepticulid mines so far. Hopefully things are just running late. One of the few species which seems to be reasonably easy to find at the moment is Stigmella plagicolella. This is also one of the easiest mines to identify as it is the classic 'tadpole' mine, with a narrow gallery leading to a blotch. It is found on Blackthorn and related species of Prunus.

Acrolepia autumnitella

It's been a long time since my last post, for which my apologies to the (very) small group who follow this blog. There's lots happening at the moment and I regularly submit pictures to the Sussex Moth Group web site so do keep an eye on that, although I appreciate you won't know what I've submitted recently and there isn't room in the caption to cover information about specific identification features!

Anyway I'll try to post at least some of the pictures on here to give you some things to go and hunt for. Do mention this blog to anyone you think might be interested, the more people there are reading it the more pressure there is on me to actually post stuff!

Anyway, I'll kick off with Acrolepia autumnitella. This is a good one to look for at the moment as you can breed the adult through very quickly and with minimal effort.

The larva mines Bittersweet (aka Woody Nightshade) Solanum dulcamara. It is an unusual mine for a Lep. as almost all frass is ejected and the mine therefore looks rather like some fly mines. If the mine is tenanted, the larva is clearly not a fly maggot! The picture above is an early mine, that below is almost full size. Note that there are characteristic patches where there is still a thin layer of green within the mine.

 

 

Taleporia tubulosa

This is the other common Psychid (together with Psyche casta and Luffia ferchaultella) which can be found in most woods. The case is totally distinctive, being about 1.5cm long and very narrow, with no grass stems or other attachments to the case. If you look at the tip of the case, you'll see that it is tri-valved.

Psychids do come to light but only very infrequently in comparison to their abundance in the larval stage so they are well worth recording now.

Psyche casta

This is another common species that most people should be able to find. The larval cases are covered in sections of dead grass and are unmistakeable. I say that but it isn't strictly true! There is another species called Psyche crassiorella which makes an identical case (although it is supposed to be slightly larger). However, casta is very common and crassiorella hasn't been recorded in the UK for at least 30 years so you are pretty safe recording cases as casta. If you really want to be sure, you will need to breed the adult and count its antennal segments (although there is a lot of overlap in the number of segments) or dissect.

Psyche casta cases can be found in a wide variety of situations, from tree trunks to fence posts, road signs and wheelie bins!

The blog has now passed 1000 page views since it started in early January. Considering the time of year and the awful weather, I'm really pleased with the level of interest. Many thanks for your support.

One for everybody - Coleophora serratella

A lot of the things I've posted recently have been quite local, or at least habitat restricted. This has not been through design, they just happen to be the things I've bumped into. Todays species in contrast, is something that everyone should be able to find.

Coleophora serratella feeds on a range of deciduous trees but is particularly common on birch. Like almost all the species in this genus, the larva inhabits a case from which it makes blotch mines with an entrance hole on the underside of the leaf.

The larva mines as far as it can reach whilst keeping it's 'tail' within the case and then it moves to make a fresh mine, either on the same leaf as shown above or on another leaf nearby. 

C. serratella makes two different cases; one in which it overwinters and feeds briefly in the spring, and then a larger case in which it completes its development.

The picture above shows the overwintering case that has been afixed to the base of the leaf. Next to the case is an excised piece of leaf that has been used to make the new case. The spring case is shown below.

Larval feeding signs alone cannot be used to record this species as there are other Colephora species which feed on birch (and other trees). If the case is not on one of the leaves where the feeding signs are, looking at adjacent twigs as it may be fixed to them for pupation.

Luffia species

The status of Luffia species in Britain has been confused for some time. The checklist and most books list two species; L. lapidella which has a wingless female but fully winged male and is only known from Cornwall, and L. ferchaultella for which only the wingless parthenogenetic female is known.

My understanding is that recent genetic research has shown that these are in fact a single species and the name lapidella has precedence but until this is published in the forthcoming new checklist or elsewhere, I guess we should stick with calling the form found away from Cornwall L. ferchaultella. 

Whatever its taxanomic status, Luffia cases can be found on tree trunks and occasionally other wood or rock. It seems to be particularly common on oak. The cases are only around 5mm long and are covered in algae so are quite hard to see.

Mompha miscella

The larvae of Mompha miscella can currently be found mining the leaves of rock-roses Helianthemum spp. The mine starts as a gallery but is then expanded to a blotch and can fill the whole leaf. The larva can change leaves. As it matures, the larva develops a strong pink tinge which can be seen when the larva is viewed against strong light.

Oak bark miners

Strange as it may seem, there are species which mine the bark of young oak trees. They are found mining the smooth bark of young saplings, usually ones that are about 3 - 5 inches across at chest height. Apparently they can also mine branches of larger oaks but I have never seen this myself.

Until a couple of years ago, identification was easy; it was Ectoedemia atrifrontella. However E. longicaudella has now been found in Britain and the mines are inseparable. The only way to resolve identification then is to coppice the oak and breed through the adult. As most records in the past have been of mines and therefore can now only be referred to one or the other, we have very little knowledge of the distribution of either species and obtaining definitive records is very worthwhile.

Many of the mines I have seen have been on scrubby oaks on heathland so site managers may be happy for you to contribute some scrub clearance!

Argyresthia glabratella

This species is undoubtedly under recorded but the larval feeding signs can currently be found on Norway Spruce Picea abies. Look for twigs that have lost the needles from the end (some dead needles may be retained at the tip). Then look for a small circular hole in the twig, usually on the underside. The larva pupates within the twig so if you keep it, you should get an adult in June.

Elachista nobilella

This species was only discovered in the UK a few years ago; by Graham Collins in Surrey. It has subsequently been found in most other counties in the south-east but as all the records have been made by a small number of people who are aware of its existence and know how to find it, the true distribution could be much wider.

The larvae mine the leaves of Wavy Hair-grass Deschampsia flexuosa. Surely it isn't possible to fit a larva inside a Wavy Hair-grass leaf? Well it is! Two occupied mines are shown below.

The moth seems to like plants that are in woodland, at least partially shaded and often on a bank or ridge. They also seem to like scattered plants, rather than the extensive 'lawns' that Wavy Hair-grass often forms, although it may just be that it is easier to see the mines when there isn't too much potential habitat! I found a number of vacated mines today so if you want to look for this species, you had better do it soon. A picture of the habitat where one of the occupied mines was found is shown below.

Grass ID guide needed

John Langmaid joined me for some fieldwork on Wednesday so, inevitably, having a grown-up present, I saw a couple of species I've not seen in the larval stage before. Spring is the best time to look for most Elachista species as larvae and as most of them rarely seem to come to light, this is the best way to record them.

The down side is that most Elachistas mine grasses, sedges or rushes! So, get your grasses book out or hire a tame botanist and have a look for:

This is Elachista humilis and the larval foodplant is Tufted Hair-grass Deschampsia cespitosa.

The Nationally Scarce Elachista obliquella produces a simlar mine on False Brome Brachypodium sylvaticum although the leaf is somewhat more twisted by the mine.

Nemapogon clematella

The larvae of Nemapogon clematella feed in fungus on a variety of trees and shrubs and can be detected by frass exuded from the fungus. This seems to be particularly easy to find on the small black fungus that occurs commonly on dead Hazel stems in overstood coppice. The moth can be bred easily.

Norway Spruce

So why have I got a bag of Norway Spruce cones in my house? Well it isn't to spray them for christmas decorations!

The larvae of two species can be bred from Norway Spruce cones collected at this time of year; Assara terebrella and Cydia strobilella. Cones containing A. terebrella larvae are reported to be stunted and sometimes deformed but those with C. strobilella rarely show any external signs of being occupied so you just need to collect a random selection. Whilst A. terebrella comes to light, people don't often trap conifer plantations so it is under recorded. C. strobilella flies around the top of spruces in afternoon sunshine and is therefore rarely recorded as an adult.

Cones that are collected now should be kept in a container that allows circulation of air (to prevent mould) but you will obviously need to have some sort of netting over the container to prevent any emerging adults from disappearing before you notice them! I give the cones a light spray with water occasionally.

Broom - adding to the confusion

I found some more mines on Broom over the weekend and, wanting to try to get a decent photo of the mine of Trifurcula immundella or Leucoptera spartifoliella, I brought one back. It's a difficult mine to photograph but you should be able to see that it starts on the uppermost right hand branch, goes down the right hand side of the main stem before moving to the front of the stem by the middle right hand branch then turning by the lower left branch to start travelling back up again. This mining down then up method is referred to immundella in some of the literature but there was no sign of an egg, even under the microscope, which means it should be spartifoliella. I decided to open the mine to make sure and the larva is clearly immundella. I would recommend that if you can't see an egg, you open the mine and have a look at the larva to confirm which species it is.

Moths on Broom in winter

There are a few things that can be looked for on Broom at this time of year (and it's much easier when there are no leaves in the way!). They range from the very common and easy to find, to the somewhat more difficult but if you know somewhere with a few bushes you should be able to find at least one species.

Agonopterix assimilella larvae seem to be everywhere I look. They spin a couple of twigs together as shown below (although the silk may not be quite as obvious as in this example).

It is important that you gently pull the twigs apart until you can see the larva and check that it looks like the photo below. This is because the dreaded Light Brown Apple Moth has been recorded on Broom and makes a similar spinning. No doubt there will be other polyphagous species that also do something similar.

The other three species are all miners. In all cases they mine the most recent years growth so the mines will be found relatively near the end of the twigs. The mines of Leucoptera spartifoliella and Trifurcula immundella are, in my opinion, inseparable. Some literature states that one species mines up the twig and then back down, whilst the other mines down the twig and then back up. However in my experience this is not reliable. My pictures of the mines are not great, nor are those I can find on the web but both mines are blackish as can be seen in the photo below.

The way to separate the species is that the egg of T. immundella stays fixed on the twig at the base of the mine, whilst that of L. spartifoliella falls off soon after the larva hatches. The photo shows the egg of immundella at the start of the mine.

If you want confirmation, you can carefully dissect the mine and look at the larvae which are very different:

The larva of T. immundella is shown above and that of L. spartifoliella below.

The final species, and perhaps the hardest to find, is Phyllonorycter scopariella. The mine is shorter than the two preceeding species and tends to be greyer or browner. The books say that the mine is 'inflated' and this is true if you use your imagination a bit!

Pond dipping

Whilst looking for a rare Coleophora in Norfolk on New Years Day I noticed some reedmace with damage to the seedheads (see below).

This rang a vague bell about 898 Limnaecia phragmitella so I picked a seedhead to have a look for larvae. I expected the larvae to be hidden within the seedhead but they were feeding on the outside. This species will feed on both Common and Lesser Reedmace.

Finishing off Holm Oak

Below are upper and underside views of the blotch mine caused by Phyllonorycter messaniella on Holm Oak. At this time of year the underside 'skin' of the leaf mine is often torn but it should still be recognisable.
If the mine is intact, note the crease which is a feature of many Phyllonorycter mines.