Blue Doctor Butterfly vs Klamath Weed Beetle

Side-by-side species comparison

Attribute Blue Doctor Butterfly Klamath Weed Beetle
Scientific Name Rhetus periander Chrysolina quadrigemina
Order Lepidoptera Coleoptera
Family Riodinidae Chrysomelidae
Size 55-65 mm wingspan 5-7 mm
Habitat Rivers & Streams Grasslands
Diet Herbivores Herbivores
Regions South America (Brazil, Peru, Colombia, Ecuador, Venezuela, Bolivia) Europe (native), introduced to North America, Australia
Conservation Least Concern Least Concern

Blue Doctor Butterfly

A large metalmark butterfly with brilliant metallic blue upperwings and distinctive red-spotted underwings with long tail streamers. It is one of the largest and most spectacular members of the family Riodinidae. Males are territorial and frequently seen perching on sunlit leaves.

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Did You Know?

Despite being a metalmark butterfly rather than a swallowtail, it has evolved long tail streamers on its hindwings through convergent evolution.

Klamath Weed Beetle

A dark bronze to coppery-brown beetle with a convex, heavily punctured body. It was introduced to control the invasive Klamath weed (St. John's wort) and became a classic biocontrol success story.

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Did You Know?

Its introduction to California in the 1940s reduced Klamath weed infestations by over 99%, saving millions of acres of rangeland.