Cryptolestes pusillus

Small, flattened beetle typical of the genus Cryptolestes. Distinguishable from the closely related Cryptolestes ferrugineus (rust-red grain beetle) by differences in pheromone response patterns; C. pusillus shows less specificity to its own aggregation pheromone components and paradoxically responds more strongly to heterospecific pheromones of C. ferrugineus. Antennal morphology and electroantennogram responses can aid identification, with females showing larger EAG responses than males.

Stored grain products and bulk paddy grain; associated with human-modified environments including granaries, warehouses, and food storage facilities.

Native to Europe; now present in North America (including Canada, where it is considered a pest), Oceania, and other regions. Distribution records indicate widespread establishment in stored product systems globally.

Grain products; specifically documented feeding on bulk paddy grain and various stored cereals.

Egg, larva, pupa, and adult stages. Laboratory studies indicate incubation periods of approximately 4–7 days and total developmental periods of 40–72 days depending on conditions. Adult longevity has been recorded at 65–170 days under laboratory conditions, varying with environmental factors.

Exhibits aggregation behavior mediated by pheromones. Responds to synthetic lactone components of aggregation pheromones; females demonstrate larger electroantennogram responses than males. Shows less pheromone specificity than congeners, with equal response to both components of its own pheromone and stronger behavioral response to pheromone components of Cryptolestes ferrugineus than to its own—a novel preference among cucujid beetles.

Pest of stored grain products; serves as prey for predatory insects such as Xylocoris flavipes (Hemiptera: Anthocoridae) and as host for ectoparasitoids including Plastanoxus westwoodi (Hymenoptera: Bethylidae), which parasitizes larvae and pupae.

Significant economic pest of stored grain products, particularly in Canada and other regions with developed grain storage infrastructure. Subject to integrated pest management research including biological control and botanical extract treatments.

• Cryptolestes ferrugineusSimilar morphology and ecology as a stored grain pest; distinguished by pheromone response patterns, with C. pusillus showing greater response to C. ferrugineus pheromones than to its own.

• stored product pest
• grain beetle
• biological control model
• pheromone response
• cosmopolitan pest

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Grasshopper Collections and Survey
• Plains Lubber Grasshopper
• Rust-red grain beetle,Cryptolestes ferrugineus, and flat grain beetle,Cryptolestes pusillus: Antennal and behavioral responses to synthetic components of their aggregation pheromones
• Fertility Life Tables of <i>Plastanoxus westwoodi</i> (Kieffer) (Hymenoptera: Bethylidae) on <i>Cryptolestes pusillus</i> (Schon.) (Coleoptera: Cucujidae)
• Effect of Temperature on the Predator, <Xylocoris flavipes</i> (Reuter) (Hemiptera: Anthocordiae) Feeding on <i>Cryptolestes pusillus</i> (Schon.) (Coleoptera: Cucujidae)
• Effect of Acetonic Extracts of <i>Calotropis procera</i> R Br.in (Ait.) on Reproductive Potential of Flat Grain Beetle <i>Cryptolestes pusillus</i> (Schon.) (Coleoptera: Cucujidae)
• Trap Count Characteristics of the Flat Grain Beetle Cryptolestes pusillus in Bulk Paddy Grain: Relationships with Insect Density.