Sawtoothed grain beetle

Definition

A small, flattened beetle (Oryzaephilus surinamensis, family Silvanidae) recognized by the six saw-like projections on each side of the pronotum. A cosmopolitan pest of stored grain, flour, dried fruit, chocolate, and other dry goods; adults and larvae feed on damaged kernels and fines, often spreading fungal contamination. Unlike some stored-product pests, it cannot attack sound, intact grain. The common name sometimes appears as 'saw-toothed grain beetle' or simply 'malt beetle' in older literature.

Etymology

From the serrated, saw-like lateral margins of the pronotum; 'grain beetle' denotes its economic habitat.

Example

In grain elevator monitoring programs, pheromone traps for the sawtoothed grain beetle often capture adults alongside the merchant grain beetle (Oryzaephilus mercator), requiring microscopic examination of the antennal club to distinguish the two species.

Synonyms

• malt beetle

Related Terms

• Oryzaephilus mercator
• stored-product entomology
• silvanid
• Cucujoidea
• grain pest
• Khapra beetle
• Confused flour beetle

Usage Notes

Often confused with the closely related merchant grain beetle (Oryzaephilus mercator), which has a slightly larger eye and differently shaped antennal club. The name 'malt beetle' appears in historical texts and may refer to this species in literary contexts (e.g., the nursery rhyme 'This Is the House That Jack Built'). In IPM contexts, presence indicates prior grain damage or sanitation issues rather than primary infestation of sound grain.