Chickweed Geometer (Family Geometridae)

Salutations, BugFans,

This lovely little Chickweed geometer moth appeared on the BugLady’s tomatoes (the male, note the fuzzy antennae) and her front porch (the female—note the plain antennae). She blames her lamentable inattention to small moths for not noticing them before, because they are allegedly pretty common.

Chickweed geometers are members of the family Geometridae. As BugFans will recall, geometer caterpillars are called inchworms—they are missing several sets of prolegs in their midsection and that causes them to “inch” (hike their rear end toward their front) rather than “undulate.”

Proceeding on the assumption that scientific names are not just meaningless tongue twisters, the BugLady loves to find out the etymology of insect names. Geometer means earth measurer. says that the genus part of a Chickweed geometer’s scientific name (Haematopsis grataria) comes from the Greek haima or haimatinos, meaning blood/of blood, probably referring to the pink markings on the wings, which can approach blood red in some individuals. On-line dictionaries attribute the species name, grataria, to a Catalonian word (Catalonia is a region of Spain) meaning “to scrape, itch, squawk or scratch.” The BugLady is going to have to chew on that one for a while. According to Donald Borror’s Dictionary of Word Roots and Combining Forms, the prefix grat, from the Latin, means pleasing or favor. A choice between grace and irritation.

Except for the far east and west coasts, CGs are found from the Rio Grande well north into Canada, especially in the eastern half of the U.S. Because their larvae eat the leaves of chickweed (and clover and smartweed and other low plants) and because lawns may be hotbeds of chickweed and clover, CGs are often found in manicured situations, where their presence is welcomed. Adults may sit on flowers, and they may pollinate flowers, but they probably do not eat. They are eaten by predators, but Sogaard, in Moths and Caterpillars of the North Woods, wonders if their cheery colors signal that they are distasteful.

CGs are another “not much else looks like this” species. Males and females are similar, with wingspreads just under an inch. Because they are colorful and diurnal (day-flying), and they perch with their wings spread flat, they are often mistaken for butterflies. Geometridae is a huge family, but Haematopsis is a tiny genus, with only this species in it.

CGs are seen throughout late spring and summer, until the first frosts. The larvae develop quickly (a month as larvae; two weeks as pupae), there are several broods throughout its range. The caterpillars from the first brood pupate briefly in a cocoon that they spin. Larvae of the final brood overwinter as pupae.

The BugLady