Mottled umber in caterpillar form, Germany
The mottled umber (Erannis defoliaria) is a moth of the family Geometridae. It is a common species throughout much of the Palearctic region.

Distribution

The species can be found in West Europe from North Scandinavia to the North Mediterranean region then East to the Caucasus, North Iran, Russia, Russian Far East, and Ussuri.


Wingless female

Illustration from John Curtis's British Entomology Volume 6
Description

The female of this species is wingless and rather spider-like and can be found on the trunks and stems of its larval food plants. She is white or yellow and black-patched. The male is fully winged (wingspan 40–45 mm) and very variable. The ground colour of the forewing is pale yellow or light yellow ochre and suffused dark grey.The basal and distal fasciae are dark brown.The basal fascia is bordered on the inner side by a brown cloud; the distal fascia has a brown cloud on the outer edge.There is also a brown cloud along the costa.There are two dark brown oblong spots in the upper half of the terminal area. The hindwing is grey-white with grey suffusion.There is a grey-black discal spot on both wings.There are numerous and significant deviations from this colour pattern and some specimens are very dark. Truly melanic forms are also frequent. As with the peppered moth, the darker forms tend to be prevalent in industrial areas.

Biology

The adults are active from September to December and the males are attracted to light.

The larva is also very variable from cream to dark brown. It feeds on a wide variety of trees and shrubs (see list below) and can be a serious pest in orchards. The species overwinters as an egg.


Caterpillar
^ The flight season refers to the British Isles. This may vary in other parts of the range.
Recorded food plants

Abies - Fir
Acer - Maple
Amelanchier
Betula - Birch
Castanea - Chestnut
Corylus - Hazel
Cotoneaster
Crataegus - Hawthorn
Fagus - Beech
Hippophae - Sea-buckthorn
Larix - Larch
Lonicera - Honeysuckle
Malus - Apple
Prunus
Pyrus - Pear
Quercus - Oak
Ribes - Currant
Rosa - Rose
Sorbus
Tilia - Lime
Ulmus - Elm