This week’s guest blog comes from Helen Rowe and explores the winged wonders that are our native butterflies and moths. As well as being Aberdeenshire Council Countryside Ranger for the Marr area, Helen is a keen Lepidopterist (studies butterflies and moths). She is the South Aberdeenshire county moth recorder (checks volunteer recorders’ moth sightings in the area for submission to our local biological records centre, NESBReC and the National Moth Recording Scheme) and Aberdeenshire area organiser for Butterfly Conservation East Scotland Branch (coordinates local events and surveys).
From childhood I’ve loved butterflies and moths for their beauty and diversity, with camouflage or warning colours to try to evade predation through their life-cycle stages. The variety of colours and complexity of patterns the adults display comes from the arrangement of microscopic scales that cover their wings and bodies like a mosaic of tiny overlapping roof tiles. Lepidoptera, the scientific name for their insect order is from ancient Greek words lepís = “scale” + pterón = “wing”. They’re also important in ecosystems, as a food source, e.g. many nesting birds feed their chicks on caterpillars, e.g. up to 10,000 may be needed to rear a brood of blue tits – we have a nest in our garden due to hatch any day now! – and several are pollinators. Over 1000 species have been recorded in NE Scotland (up to 30 butterflies & the rest are moths), but I’ll focus on a few that are on the wing now, perhaps to look out for on exercise walks from home, depending where you are, and some may be seen in your garden. Peacocks and Small Tortoiseshells that have overwintered as adults are still around at this time of year but are starting to look faded and worn. It can be hard work for males to find a mate – if you’ve ever seen butterflies spiralling rapidly up in the air together, these are typically rival males battling it out for territory to court females. The urgent search for a mate sometimes results in cases of mistaken identity. I recently witnessed a Small Tortoiseshell trying to court a Peacock – the latter just sat still with wings tight shut until the former gave up making advances and flew off. Females of both species will now be laying egg batches on sunny nettle patches to start the next generation.
A couple of weeks ago in Aberdeen I was pleased to see a Comma, named after the white punctuation mark on the underside of its wings. Still uncommon in Aberdeenshire, numbers of this dead leaf-disguised butterfly have increased in recent years, especially on Deeside, with both spring and late summer/early autumn sightings indicating it’s now overwintering and breeding locally, perhaps as a result of climate change, but has also made a comeback in many parts of the UK. This species is thought to have transitioned to nettles as its main caterpillar food-plant relatively recently. It also feeds on elm, but many trees succumbed to disease and it was once known as a pest on hops in the now long-gone hop gardens of southern England.
We’re now seeing some of the white butterflies, having emerged from their overwintering chrysalis stage. The Green-veined White, that is not a ‘cabbage white’ but as a caterpillar feeds on leaves of crucifers, e.g. Cuckoo Flower, Garlic Mustard, is the commonest in our region. At close range it can be identified by the dark-greenish speckled veins on the underside of its wings.
The Orange-tip is also widespread, and the male has very distinctive orange wingtips, but both sexes have a marbled yellow/black mix on white pattern on their hindwing undersides. It also lays eggs on crucifers, but the caterpillars eat the flowerheads and developing seed pods. They’re also cannibalistic so usually only one orange egg is laid per flower, to avoid them meeting and eating each other! Can you spot the egg in the photo?
A fiery gem of a butterfly, the Small Copper is one to especially keep an eye out for at the moment as Butterfly Conservation Scotland is running a survey to find out more about where this species occurs: https://butterfly-conservation.org/in-your-area/scottish-office/scottish-small-copper-survey
Green Hairstreaks are also on the wing now – look for them around patches of blaeberry – their usual larval foodplant in our area, though their colour against fresh green leaves and diminutive size makes them hard to spot until they move – territorial males will fly up from favoured perches to counter any intruders to their patch. The bright green underside wing colour is an iridescent optical illusion created by the structure of their scales.
Speckled Woods should also be appearing – like the Comma, they were rarely seen in Aberdeenshire (apart from in the north-west towards the Moray Firth) until recent years, but have been spreading from the NW as well as from the south and can now be locally common in some woodlands.
My favourite spring butterfly is probably the Pearl-bordered Fritillary, having studied this species for many years, including annual surveys along Cambus O’ May riverbank (although that may not happen this year!) – and also because it has a beautiful chequered pattern. The name comes from the string of pearls that borders the underside of the hindwings and ‘fritillary’ is from the Latin word fritillus, meaning dice box (which were formerly chequered). A speciality of Deeside from around Potarch all the way up to Mar Lodge Estate, this is a fussy butterfly. It likes sheltered, usually south-facing slopes, with bare ground and/or leaf litter, often bracken, for the caterpillars to bask on in early spring to warm up, which aids their digestion! They only eat violets and the adults need nectar plants such as bugle and dandelion, so all these ingredients are needed to support a colony. This butterfly used to be common across much of Britain and was known as the ‘woodman’s friend’ as it followed woodland clearings created by coppicing, a practice which died out and the butterflies with it. Thankfully it seems to be thriving on Deeside, with record counts made on some sites last spring.
Many moth species are in the larval stage at present (to help feed all those hungry bird nestlings!), but a number are adults now. Day-flying Emperor Moth males may be seen whizzing around moorland and open woodland to detect female pheromone (chemical scent cocktail) trails from up to a few miles away with their feathery antennae. The adults of this species lack mouthparts so must find a mate before ‘their batteries run out’, probably a week after emergence from their cocoons at most. The false eyespots on their wings may scare off some predators. Their caterpillars eat various plants but are often on heather in the highlands.
Another mainly diurnal moth out now is the Ruby Tiger – as well as having reddish wings, its body and parts of its legs are red underneath as an ‘I taste nasty’ warning to would-be predators.
A recent highlight for me was successfully rearing a Puss Moth I found as a small caterpillar last year, which overwintered as a cocoon kept in the garden shed. Many species are easy to rear from eggs or larvae to pupae then adults if you have the right food-plants available – this one likes aspen and willow. I used to do so as a child and still rear species found locally, as caterpillars always provoke interest with school groups and at ranger events. The furry cat-like moth looks very different from its caterpillar, which has multiple defences – when threatened it waves its head about displaying quite a startling face, spits acid and protrudes pink ‘whips’ from its two tails!
Butterflies and moths are very sensitive to environmental change so are useful indicators of the health of our environment, and long-term studies have shown changes in distribution and abundance of many species, and although some are increasing, several are declining. So see what butterflies and moths you can spot in your garden or nearby and send in your sightings. Check out these Scottish regional ID guides: https://butterfly-conservation.org/in-your-area/scottish-office/butterfly-and-moth-identification-guides and habitat and species leaflets: https://butterfly-conservation.org/in-your-area/scottish-office/habitat-and-species-leaflets