Synonyms and other taxonomic changes
The classification used at BugGuide follows
All-Leps, which appears to follow Scoble
et al (1999), the same source followed by CBIF's
The Geometroidea of CanadaExplanation of Names
GEOMETRIDAE: from the Greek "geo" (the earth) + "metron" (measure); refers to the larvae, which appear to "measure the earth" as they move in a looping fashion
Numbers
more than 1,400 species in 6 subfamilies in North America listed at
All-Leps
about 35,000 species worldwide
Size
adults small to medium-sized (wingspan 15-50 mm)
Identification
adults usually have slender bodies and relatively large, broad forewings, often crossed by thin wavy lines; females of some species are wingless or have flightless atrophied wings
when at rest, many geometrid moths hold their wings away from the body and flat against the substrate (in contrast to most noctuid moths, which tend to fold their wings over their abdomen); some species/genera hold their wings in a characteristic position such as: flat & at right-angles to the body, or inclined 45 degrees above horizontal, or vertically over their back like a butterfly
forewing cubitus vein appears 3-branched; hindwing subcostal vein bends abruptly downward at base
larvae generally have only two pairs of prolegs (at the hind end) rather than the usual five pairs in most lepidoptera; the lack of prolegs in the middle of the body necessitates the peculiar method of locomtion, drawing the hind end up to the thoracic legs to form a loop, and then extending the body forward
Range
throughout North America and the world
Habitat
larvae found on host plants in various vegetated habitats
adults usually nearby, but most are nocturnal and attracted to light; a number of species are day-flying
Season
early spring through late fall, depending on species
Food
most larvae feed on the leaves of woody plants (coniferous and deciduous trees, shrubs); some species eat herbaceous plants
many species are economically important pests of fruit trees, forest trees, and berry crops
See Also
The genus
Zale in the Erebidae, which has pretty much the same characteristic outline as the Geometridae:
Internet References
pinned adult images and provincial/territorial lists of the 500+ species in Canada (Troubridge and Lafontaine, The Geometroidea of Canada)
live larva images of 38 eastern NA species, plus descriptions and information on biology etc. (geometrid Caterpillars of Eastern Forests; US Geological Survey)
adult thumbnail images of geometers from Thailand, showing diversity of color, pattern, and form (thaibugs.com)
brief overview of family with sample adult photos of each North American subfamily (Friends' Central School, Wynnewood, Pennsylvania)
