Lesser Grain Borer vs Klamath Weed Beetle

Side-by-side species comparison

Attribute Lesser Grain Borer Klamath Weed Beetle
Scientific Name Rhyzopertha dominica Chrysolina quadrigemina
Order Coleoptera Coleoptera
Family Bostrichidae Chrysomelidae
Size 2-3 mm 5-7 mm
Habitat Gardens Grasslands
Diet Seed Feeders Herbivores
Regions Worldwide tropical and subtropical regions Europe (native), introduced to North America, Australia
Conservation Not Evaluated Least Concern

Lesser Grain Borer

A cylindrical dark brown beetle that bores into whole grain kernels, reducing them to powder. It is especially destructive in warm tropical grain stores.

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Did You Know?

It produces a distinctive sweet, musty odor that can taint infested grain.

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.