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.