Small Eggar

    Scientific name: Eriogaster lanestris

    Flies at night in January to March and occasionally comes light.

    The female is larger than the male, having a large tuft of grey hair at the end of abdomen, which is used to cover the egg batches.


    • Small/Medium Sized 
    • Wing Span Range (male to female) - 36-47mm

    Conservation status

    • Nationally Scarce

    Caterpillar Description

    Overwinters as a pupa in a hard, brown, rounded cocoon, usually near the ground, but has been found in a bat box up a tree. The pupa often passes two or three winters before the adult emerges, and in captivity sometimes up to seven. Larvae April to July, living gregariously, until part way through the final instar, in a compact web, which can reach the size of a small football, often basking on this during warm sunshine. Hedges and bushes lightly trimmed in the autumn are preferred to uncut ones.

    Particular Caterpillar Food Plants

    Blackthorn (Prunus spinosa) or Hawthorn (Crataegus monogyna), occasionally elms (Ulmus spp.), Spindle (Euonymus europaeus), Apple (Malus domestica) and Grey Willow (Salix cinerea).


    • Countries – England, Wales
    • Most frequent in Somerset and Dorset, also in Gloucestershire, Wiltshire, Sussex, Oxfordshire. Also found along parts of the Welsh border, in parts of the East Midlands and East Anglia, parts of Yorkshire and historically from Lancashire.
    • Distribution Trend Since 1970’s = Britain: Declining


    Hedgerows and scattered bushes in open country.