Phyllotreta cruciferae

Definition

A species of flea beetle (Coleoptera: Chrysomelidae) native to the Palearctic and introduced to North America, specialized on cruciferous host plants. Adults are small (1.5–2.5 mm), metallic bronze or black, with enlarged hind femora enabling characteristic jumping dispersal. Larvae feed on roots while adults skeletonize leaves, making it a significant economic pest of canola, rapeseed, and other Brassicaceae crops.

Etymology

Genus from Greek phyllon (leaf) + tretos (pierced, perforated), referring to leaf-mine feeding habit of some congeners; specific epithet from Latin crucifer (cross-bearer), denoting association with cruciferous plants (Brassicaceae).

Example

In the Canadian prairies, Phyllotreta cruciferae is the dominant flea beetle species in early-season canola, with economic thresholds typically set at 25% leaf area damage or 25 beetles per plant before flowering.

Synonyms

• Crucifer flea beetle
• canola flea beetle
• rape flea beetle

Related Terms

• Phyllotreta striolata
• flea beetle
• Chrysomelidae
• Brassicaceae
• Integrated Pest Management
• Economic threshold

Usage Notes

Often co-occurs with Phyllotreta striolata (striped flea beetle) in North American canola; the two species require differentiation for management timing as P. striolata emerges slightly earlier and shows greater tolerance to some neonicotinoid seed treatments. The species complex was historically confused with P. atra; modern identification relies on subtle elytral punctation and male genitalia.