Tuesday 7 February 2023

Cosmopterix pulchrimella

Since it was first discovered in Britain in west Dorset in 2001, Cosmopterix pulchrimella has spread rapidly. Initially the main spread was along the south coast but it is now found inland and as far north as Cambridgeshire.

The larvae mine the leaves of Pellitory-of-the-Wall Parietaria judaica, forming an irregular blotch. The mine initially looks whitish but rapidly turns brown. If held up to the light, a fine speckling can be seen within the mine. The mine shown below is occupied but the larva is often surprisingly difficult to see, in this instance it is at the far left hand end of the mine.

No other Lepidoptera are known to mine Pellitory in Britain but three Agromyzid flies have been recorded. These all make gallery mines. Sometimes the gallery mines can be sufficiently contorted that they form a false blotch but the gallery nature of the mine can still be determined and there are distinct frass grains so confusion with C, pulchrimella should not occur.

Large quantities of the foodplant are not needed, even a small isolated plant can be occupied. The attractive moth can easily be bred.

Sunday 14 April 2013

Coleophora cases on heather

Now is a good time to search for the two Coleophora species that feed on heather. Coleophora pyrrhulipennella cases are black and made of silk, whereas those of C. juncicolella are made from fragments of heather and are incredibly cryptic.

Both species are best found by sweeping heather. The pyrrhulipennella case is sufficiently obvious that it can be found by searching through the swept detritus.

However, the cases of juncicolella are so difficult to find that the best technique is to place your sweepings in a container overnight and you'll then find that the larvae have climbed up the sides.

It may or may not be of note that I swept lots of cases from an ungrazed heath two days ago but none at all with a similar amount of effort on a grazed heath today.

Saturday 30 March 2013

Biselachista cinereopunctella

Despite the cold weather Biselachista cinereopunctella larvae seem to be about on schedule. The larvae mine Glaucous Sedge Carex flacca and the attractive larva is very distinctive. The moth has a preference for plants growing in shaded situations.

Thursday 4 October 2012

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

Thursday 27 September 2012

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.