Moth Report Spring 2024

Mike Halsey writes:

With some sadness, this is my final report for the Society’s newsletter. I’ve just looked back and noticed that, in the best of English traditions, most reports have started with a comment on the weather! Continuing this to the bitter end, the extremely wet Spring has made it hard to get out in the field (with a lot of the Reserve under water) but this doesn’t curtail Lepidopteran activity, and on the few occasions when work has been possible, there’s been lots to see. Hopefully, as I write, we’ve seen the last of any truly cold weather; certainly the budding of trees suggests this, with some willows having been in good leaf since early February, and back garden magnolias having, for the first time in many years, successfully flowered without being frost-burnt.

In all stages of their life-cycles, moths have evolved various defences against predation; strategies include such things as concealment, camouflage or chemical defence (e.g. being toxic or possessing stinging spines).  Below  is a picture of a common moth, a species frequently seen at Fleet Pond in Spring, the Pine Beauty. It flies at night and is attracted to light, but by day sits on the tips of pine fronds, demonstrating wonderful camouflage.

In February, it was nice to see a couple of specimens of one of the late winter species not previously seen at the Pond – the Small Brindled Beauty. The photo below shows two somewhat different colour morphs, again displaying great camouflage.

I’ve commented numerous times over the past two years on the changing fauna, including species arriving in the UK from the continent (and beyond) and settling … also on one of underlying reasons for this, i.e. the changing climate. One of the recent colonisers has been the Gypsy Moth, having a male flying by both day and night in late July and August, and a female which, while winged, doesn’t fly.  Males – quite powerful fliers – have regularly been seen in the UK over the past decades, normally arriving from Continental Europe at the same time as other species that are not ordinarily UK resident, but with a flightless female, it’s hard to conclude how the species has come to naturally colonise the UK; it’s possibly been through accidental importation with plant material, the UK having poor bio-security.  However it happened, it’s clearly very much resident now in many places, including at Fleet Pond, with a batch of eggs found this winter on an oak tree along the track near the station car park (pictured below).

The eggs are covered in hairs from the tip of the female’s abdomen and act as defence against parasitic wasps.

The larvae (pictured below) are covered in quite sharp bristles and probably make it difficult for most wasps to get close enough to the larva to be a serious threat.

There’s a lot to look forward to now we’re well into Spring and the weather is starting to warm up.  We’re right in the middle of the ‘Eriocraniidae’ season now; these are early-evolving moths (the family arose something like 140 million years ago); they’re small and difficult to photograph, but at the risk of repetition, I’m going to sign off by including a photo below, which I included last year, of a species called Eriocrania sparrmanella simply because I don’t like to miss opportunities to include something so extraordinarily beautiful. Who can possibly say moths are dull?

And with so many areas of the reserve recently ‘opened up’ with the removal of holly, bramble and other understory, if you do see lights out in the marsh or on the heaths at night, feel free to come along and say Hi.

Photo credits: Pine Beauty – Keith Tailby; Eriocrania sparrmannella, a cropped section of an image taken by Patrick Clement; all other photos – Mike Halsey.