The Notodontidae are commonly known as the Prominents or Kitten moths. There are around 2800 species described worldwide, and about 22 species have been recorded in the British Isles of which 18 are native and the others are visitors from the continent. There are no Notodontontidae in New Zealand.
The adults are furry, thick-bodied moths that do not feed and are rarely seen during the day. Fore wing length ranges from 16 - 50 mm. The caterpillars vary quite a bit in shape. Some have "tails" and projections that they raise to frighten off predators.
Above is the caterpillar of Phalera bucephala, the Buff-tip. Caterpillars can be seen feeding from July through to October. Initially they feed in groups by day and night, but later they disperse to feed singly. The foodplants include sallows, birches, oaks, hazel, and many other broadleaved trees and shrubs, usually in sunny sites such as open woodland, scrub and hedgerows. It is fairly common but rarer in the north. The caterpillar can grow up to 60 mm. And is covered in white hairs with an inverted yellow V-shaped marking on its head. This photograph above was taken in late August when the caterpillar was crossing a road probably looking for a place to dig into the soil. It will overwinter in an earthen cocoon.
The caterpillar above built a cocoon in a tub of soil I provided, and the next spring hatched out. I gently combed through the soil with my fingers and extracted the cocoon, above. The line of fracture is clearly seen, as are the spiracles. The white filmy stuff would have linked the spiracles to the outside, and were pulled out as the adult (below) emerged.
Adults have a forewing length of 22 - 26 mm in the male and 26 - 34 mm in the female, and a wingspan of 44 - 68 mm. At rest this moth looks just like a twig broken at one end, this is perfectly seen in the photograph above and below. They fly from May - August.
There is one generation a year. Eggs are laid in groups on the underside of foodplant leaves. The caterpillars can strip a branch of leaves, but should not damage a healthy plant.
This is the adult at rest on my finger. It is adorable.
This is a less common pose showing the markings on the forewings. The body of the moth is incredibly hairy/scaly, but very beautiful. However I imagine a bat would have to spit out all those scales to enjoy the fat, tasty morsel of the body.