Green Dock Beetle

Gastrophysa viridula · Order: Coleoptera · Family: Chrysomelidae

Also called: Green Dock Leaf Beetle

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.
Green Dock Beetle
Photo: TristramBrelstaff, CC BY-SA

The green dock beetle is a small metallic green beetle that lives where dock plants grow. It feeds mainly on dock and green sorrel, and its larvae can only develop on Rumex species. It breeds from March to October, producing several generations each year, with the final generation hibernating as adults.

Source: Wikipedia

How to recognize it

The legs are also metallic green and are strongly built.

Source: Wikipedia

Size

Males are about 4 mm long, while females are about 7 mm long.

Source: Wikipedia

What it eats

Adults feed mainly on dock and green sorrel, and only occasionally on other plants in the Polygonaceae, Brassicaceae, Violaceae, and Boraginaceae families. Larvae can complete development only on Rumex species.

Source: Wikipedia

Life cycle

Breeding occurs from March through October. There are two to four generations per year, and the last generation hibernates as an adult.

Source: Wikipedia

When you see it

The beetle’s active season runs from March to October.

Source: Wikipedia

Lookalikes

In North America, a similar species called Gastrophysa cyanea is also referred to as the green dock beetle.

Source: Wikipedia

Where it is found in the US

Recorded in 2 of 51 states and DC. Most records: Nebraska, Colorado.

Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Same family (Chrysomelidae)

Spotted Cucumber BeetleSpotted Cucumber BeetleDiabrotica undecimpunctataDamages trees, gardens or cropsBean WeevilBean WeevilAcanthoscelides obtectusDamages trees, gardens or cropsCowpea WeevilCowpea WeevilCallosobruchus maculatusDamages trees, gardens or cropsSwamp Milkweed Leaf BeetleSwamp Milkweed Leaf BeetleLabidomera clivicollisDamages trees, gardens or cropsAlder Leaf BeetleAlder Leaf BeetleAgelastica alniDamages trees, gardens or cropsDogbane Leaf BeetleDogbane Leaf BeetleChrysochus auratus

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Gastrophysa_viridula

Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia

Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.