GEOMETRIDAE – THE GEOMETERS
Geometridae – The Geometer Moths are known for their distinctive flight pattern, resembling zigzags or W-shaped paths. Their wings are often subtly colored with patterns that help camouflage them when resting on vegetation. The caterpillars of some species have legs only at the front and rear of the body, allowing them to move with an undulating gait, appearing to measure distances. These larvae can sometimes cause damage to host plants such as trees and shrubs. Geometridae are found in a wide range of habitats across the world and exhibit high species diversity.
- Agriopis aurantiaria – Scarce Umber
- Camptogramma bilineata – Yellow Shell
- Cyclophora puppillaria – Blair’s Mocha
- Ematurga atomaria – Common Heath
- Entephria flavicinctata – Yellow-Banded Carpet
- Epirrhoe alternata – Common Carpet
- Hypomecis punctinalis – Pale Oak Beauty
- Idaea rusticata – Least Carpet
- Idaea seriata – Small Dusty Wave
- Operophtera brumata – Winter Moth
Characteristics
- Slender-bodied moths with broad wings, often held flat at rest
- Cryptic coloration (camouflage of bark, lichen, or dead leaves)
- Primarily nocturnal, sometimes active at dusk
- Filiform or slightly pectinate antennae in males
- Delicate bodies with weak scaling, often scalloped wings
Habitat
Geometridae are found in:
- Forests, woodland edges, hedgerows, gardens, wooded meadows
- Mountainous regions, heathlands, scrub
- Dry or moist environments, depending on species and host plants
Biology
- Eggs laid on leaves or branches
- Elongated caterpillars, lacking mid-abdominal prolegs → move in a “looping” gait
- Herbivorous, often well-camouflaged (twig mimics)
- Pupation in soil, under moss, or in a very discreet cocoon
- One or several generations per year depending on the species
Common Subfamilies
- Ennominae – Many species with subtle patterns (Erannis, Biston, Colotois)
- Larentiinae – Often small, mountain species (Chloroclysta, Eupithecia)
- Sterrhinae – Small moths, pale wings (Idaea)
- Geometrinae – Green moths, sometimes iridescent (Hemithea aestivaria)
Iconic Species
- Biston betularia – Peppered Moth: famous for industrial melanism
- Opisthograptis luteolata – Brimstone Moth: bright yellow with scalloped wings
- Chloroclysta truncata, Idaea aversata, Campaea margaritata – Common in Europe
Noteworthy Traits
- Inchworm caterpillars are easy to recognize by their silhouette and movement
- Adults are attracted to light, but well-camouflaged during the day
- Some species are multivoltine, others univoltine with short flight periods
- Used as indicators of plant diversity and habitat quality
