Tuesday, November 5, 2024

Pale tussock moth caterpillar Calliteara pudibunda

 

We found this larva of a pale tussock moth crawling along the parapet of Prebends bridge, across the river Wear, in Durham.



Everything about it warned ‘don’t touch me’. It would present a challenge for most insectivorous birds, although cuckoos, with a gizzard that can cope with irritating hairs, sometimes eat them. Those deterrents inflict discomfort on tender human flesh too; finely barbed and filled with irritating fluid, they can cause dermatitis. Calliteara pudibunda was once a notorious pest of hop fields, which might explain naturalist Gilbert White’s journal entry for October 8th. 1781, noting that  ‘ …women and children have eruptions on their hands ….after they have been employed in hop picking’.  More recently, families from London’s East End, travelling to Kent for traditional hop picking work every autumn, would have been painfully familiar with these caterpillars, that they knew as ‘hop dogs’.

Pale tussock larvae are not picky about food plants and defoliate at least a dozen broadleaved tree species, including beech, hawthorn, sycamore and lime, all well represented along this riverbank. But, out of curiosity, I offered our captive some young shoots from the hop vine that twines through our garden fence. It had a nibble but was fully fed and only interested in finding somewhere dry and secure amongst the leaf litter, where it will pupate inside a cocoon woven from recycled defensive bristles.

Hatched from an egg laid last June, this wanderer - provided it hasn’t already been parasitised by an ichneumon wasp - should survive winter, metamorphosing as a beautiful pale grey moth next spring.