Another hop-dog, in the garden

 

My youngest son found this his exquisite little caterpillar of pale tussock moth Calliteara pudibunda while he was cutting down the rampant ornamental hops that festoon our garden hedge. Aside from its colour and spectacular hairiness, one of its features that fascinates me is the way it exposes bands of black skin between its segments as it walks. Its undulating progress reminds me of an accordion and I half-expect a tune to emanate from it as it hurries along.

If you disturb a pale tussock moth larva it immediately adopts a ‘curled-up hedgehog’ mode, becoming a defensive ball covered in rosettes of long, neon green whiskers, with a mane of bristles, with dense tufts like miniature shaving brushes on its back, and a menacing spike of rose-pink hairs at the tail. Everything about it warns “don’t touch me”

This caterpillar might 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: finely barbed and filled with irritating fluid, they can cause dermatitis. Calliteara pudibunda was once a notorious pest of hop fields, which might explain the naturalist Gilbert White’s journal entry for 8 October 1781, noting that “several 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, which 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. By early autumn they are fully fed and only interested in finding somewhere dry and secure, ambling off (to the tune of an imaginary accordion) among the leaf litter, where they’ll pupate inside a cocoon woven from recycled defensive bristles.

 

 

Reflexed stonecrop Sedum rupestre - a drought-adapted wall plant

 

Reflexed stonecrop Sedum rupestre, thriving amongst withered mosses on a drystone wall in Weardale.

A triple-whammy of heatwaves has frazzled plant life in parched earth everywhere, but few plant habitats suffer such a severe test of drought tolerance as a sun-drenched stone wall. Stonecrops take it in their stride, thanks to succulent leaves that can store water.

The commonest and most widespread native Sedum species is biting stonecrop Sedum acre, whose starry yellow flowers adorn walls and sand dunes. Its leaves are said to be edible, with a peppery ‘biting’ taste, which may be why reflexed stonecrop was introduced from mainland Europe in the 17th. century as a salad crop, eaten when its new leaves are fresh and succulent in spring. Reflexed sonecrop escaped from gardens soon after it arrived and was first recorded in the wild in 1660.

The plant in the photograph is growing on the garden wall of a Weardale farm that dates from the late 17th. century, so maybe the original occupants also grew it for food.

 

 

Vine weevil 'playing possum'

 

Our bath acts as a giant pitfall trap for spiders, woodlice and silverfish that often become trapped when they come to drink from a dripping tap, but this was the first weevil that has fallen in.

At first, I thought it was dead, laying on its back with legs in the air but it was performing thanatosis - the strange behaviour of some animals that pretend to be dead when they are threatened. It’s also known as ‘playing possum’, because the most famous exponent is the Virginia opossum, but many other animals do it, from grass snakes to tiny insects..

This particular individual seemed to have had a close encounter with a spider’s web and was wearing some of it like a silken vest.

The adult vine weevil is a slow-moving cumbersome beetle that cannot fly, so when disturbed it simply tucks its legs under its body and either drops to the ground or rolls onto its back, keeping perfectly still. In this state it’s hard to spot in the soil. Eventually, when it thinks the coast is clear, it stretches out a tentative leg, rocks itself until those sickle-shaped claws grip a leaf, hauls itself right-way-up and ambles away.

Vine weevils are notorious horticultural pests, because their larvae feed on the root systems of garden plants - especially those grown in pots. The first sign of their presence is wilting of the leaves, by which time they have destroyed most of the root system, symptoms I became aware of when my collection of show auriculas was devastated by their larvae.

Vine weevils are parthenogenetic, laying fertile eggs without the need for a male to fertilise them, so it only takes one weevil to start an infestation.

 

Since they can’t fly, the vine weevil in our bath must have either climbed in through an open window, arrived on our clothing or had been carried in on towels dried on the washing line in the garden.

A random digression on thanatosis

If, like me, you were a teenager in the 1960s you might have listened to a rock band called the Grateful Dead, headed by Jerry Garcia and noted for their eclectic range of musical genres.

Taxonomists - those who assign scientific names, rooted in Latin and Greek, to newly-discovered species, - are not generally noted for whimsy, but in 1987 one fan of the Grateful Dead, entomologist John H. Epler, honoured them with a scientific name for a new midge species that performs thanatosis - Dicrotendipes thanatogratus. The specific epithet, thanatogratus, means ‘grateful dead’, amalgamating thanatos (Greek for “death”) with gratus (Latin for “grateful”)