Country diary: trails of the unexpected hawthorn moth larvae

Langstone, Hampshire: In Britain these insects usually have one brood a year, but this year saw a second generation of the leaf-mining larvae's foliage trails. A result of climate change?When webbing first appeared on the cotoneaster that scrambles up the side of my neighbours' garage wall it was easy to mistake it for the work of spiders, but there were no orb weavers in residence. During the past six weeks, sheets of grey silk have spun out to veil two-thirds of the shrub. The creators of this premature Halloween decor are tiny brown ochre-coloured caterpillars, the larval stage of the hawthorn moth (Scythropia crataegella).They are predominantly associated with their namesake, but can be found on other members of the rose family and are considered a minor fruit crop pest as they occasionally attack damsons and blackthorns. The young larvae are leaf miners. Where they have burrowed into fresh tissue, the glossy green leaves are marked with pale beige meandering trails. As they mature, they graze the surface, leaving the foliage shrivelled and brown. Some sprays have been completely defoliated, clusters of scarlet berries clinging to the naked branches. The plant should recover, though the damage inflicted may affect the development of new shoots. Continue reading...