Garden Tiger

• When disturbed it flicks open its forewings to show the red hindwings, a warning flash accompanied by the secretion of a toxic fluid from the back of the neck.
• Its populations have fallen by more than 90% in the United Kingdom since the 1980s, a decline documented by light-trap monitoring that has become one of the most cited examples of the collapse of European insects.
• Its caterpillar is polyphagous, feeding on nettles, dandelions, brambles and dozens of other plants, which makes its decline all the more puzzling.
• It is a textbook example of double aposematism: the forewings, marbled in brown and cream, camouflage the moth at rest, but when disturbed it opens them and reveals red hindwings with black spots.
• And the warning is real: it accumulates toxic compounds from the plants it eats as a caterpillar, and it also secretes a yellow fluid from its thorax when attacked.
• It also emits ultrasonic clicks that interfere with the sonar of bats, a mechanism shared by several arctiid moths.
• The caterpillar, very hairy with long brown and black hairs, is popularly known as the woolly bear; its hairs cause skin irritation in some people.
• Its populations have fallen sharply in the United Kingdom and other northern European countries since the 1980s, and the decline is linked to milder, wetter winters.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Meadows, gardens, verges and woodland edges of Europe and temperate Asia

Size at birth

The caterpillar overwinters when it measures about 15 mm and reaches about 60 mm when fully grown

Sexual maturity

The adults emerge in June or July and fly at night; the male detects pheromones with bipectinate antennae

Gestation / incubation

The eggs hatch in about ten days; the caterpillar feeds for a few months, overwinters and resumes feeding in spring before pupating

Litter / clutch size

Clutches of 50 or more eggs on the leaves of a variety of herbaceous plants

Sources consulted: https://es.wikipedia.org/wiki/Arctia_caja; Wildlife Insight, ficha Garden Tiger moth; ficha de especie de Arctia caja; UKmoths; UKmoths, ficha Garden Tiger; Wildlife Insight

Best time: Adults on the wing at night in July and August, drawn to light; the caterpillars are easiest to see in autumn and early spring