Similar in appearance to the Hornet Moth it can be distinguished by the black head and shoulder and a yellow collar. It is also smaller in size.

They usually overwinter twice as larvae. In the first year the caterpillars feed close to the ground but move slightly higher up the tree trunk in the second year.

Size and Family

Similar in appearance to the Lunar Hornet Moth it can be distinguished by the yellow patches on the head and shoulder and a black collar. The adults can be found resting on poplar trunks after they have emerged in June.

They overwinter at least twice as larvae for the first and sometimes second winter and as fully grown larvae in cocoons for the second or third winter. They mainly feed on the wood just below the bark surface near ground level and emerge from a hole near the base of the trunk.

Their English name is derived from the males of the spp. humuli which are entirely white, however the females are larger with a striking yellow forewing with distinctive orange markings. The Shetland spp. thulensis is smaller with a creamy white forewing marked with brown. When at rest they hold their elongated wings almost vertically against their body.

At rest the wings are held at a low angle and the males hold their abdomen upturned. The females are slightly larger and paler in colour. The forewings have two curved cross-lines and the area between them can often be a darker shade.

The adults mainly fly at night and are attracted to light. They occasionally fly in sunshine in the oak canopy. The caterpillars can be found from late July to early the following May overwintering as larvae inside a cocoon.

The wings are a pale yellow colour which fades whiter with age, with two darker lines crossing the forewings and one line crossing the hindwings.

The adults are occasionally disturbed during the day but they are strictly nocturnal flying rapidly at night. They are attracted to light. They overwinter as caterpillars in a bark crevice.

Although there is some variation in the colour and intensity of the wing markings the most familiar form is a yellowish moth with a brown central band and obvious single black spot on the forewing. Other forms are more uniformly orange-brown in colour, deep brown or even blackish. The wings have a lightly scalloped edge.

They overwinter as an egg on the foodplant and the caterpillars can be seen between March and June.

This moth is most easily distinguished from other sallows by the deep red or pinkish-brown head and shoulders in contrast to the yellow thorax. The bright orange-yellow forewing is slightly hooked with deep-red or reddish-brown markings forming a bar from the leading to trailing edge.

They overwinter as eggs, laid in short rows on twigs close to the tree buds. The larvae can be found between late March and early June.

The forewings have two well-defined pale cross-lines and two blackish spots in the centre. The males are often darker and smaller than the female. The males can occasionally be seen flying high around oak trees.

The larvae can be seen from June to July and late August to September which then overwinter as pupae in a tough brown cocoon which is spun inside a tightly folded oak leaf.

The caterpillars have a similar colouration to the adults and can be seen from late August to the following June, overwintering on the food plant.

The adults can sometimes be found at rest on Bramble and other low foliage. They are attracted to light.

The forewings are long, narrow and rounded. They are variable in colour from reddish brown to blackish brown but with a small black dot close to the leading edge at the tip. The yellow hindwings have a narrow black band without the dark crescent or clouding found in other yellow underwings.

The adults come to light in large numbers and may be disturbed from plant debris or ground vegetation during the day. The larvae can be found from August to early spring, feeding at night and hiding underground during the day.

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