Cadelle Beetle (Tenebroides mauritanicus)

A Silent Threat in Global Grain Storage Facilities

The Cadelle Beetle (Tenebroides mauritanicus) is a cosmopolitan pest in the family Trogossitidae, commonly found in grain storage facilities, agricultural warehouses, and dry crop storage areas. This beetle causes damage by direct feeding and by creating access points for secondary pests. Its high tolerance to environmental conditions makes it difficult to manage if not controlled properly.

Taxonomic Information

• Common Name: Cadelle Beetle
• Scientific Name:Tenebroides mauritanicus (Linnaeus)
• Family: Trogossitidae
• Order: Coleoptera

Morphology

• Body Length: 5.0 – 11.0 mm
• Color: Glossy black
• Antennae: Clavate (club-shaped)
• Forewings (elytra): Hardened with longitudinal grooves
• Hindwings: Membranous and transparent
• Legs: Walking type

Distinctive Features:

• Head and thorax tightly fused
• Noticeable narrowing between thorax and abdomen ("waist-like")
• Smooth pronotal margin, slightly pointed at the top

Life Cycle (Complete Metamorphosis)

• Duration: 7–10 days
• Female lays up to 1,000 eggs
• Eggs are elongated and off-white

• Duration: ~43 days
• Flattened body, grayish-white
• Undergoes 3–7 molts

• Duration: ~7 days
• Pupates inside seeds or wood crevices

• Lifespan: 1–3 years
• Total life cycle: ~2 months

Host Plants & Damage Symptoms

Common Hosts:

• Grains (e.g., maize, sorghum, wheat)
• Oilseeds (e.g., palm kernel, olive, sunflower)
• Seeds from the Gramineae and Compositae families

Damage:

• Eggs laid in cracks of seeds or wooden structures
• Larvae bore into the seed’s embryo, damaging germination potential
• Final instars construct pupal chambers inside seeds
• Both larvae and adults tolerate low oxygen (e.g., sealed storage)
• Can also prey on eggs and larvae of other storage insects

Distribution

Tenebroides mauritanicus is widespread in tropical and subtropical regions and can be found year-round in poorly managed storage facilities.

Prevention & Control Measures

✅ Preventive Actions:

• Remove and discard infested products promptly
• Avoid storing grains in humid or uncontrolled environments
• Inspect for cracks in seeds and packaging—common egg-laying sites

✅ Control Methods:

• Apply targeted insecticides to high-risk areas
• Consider fumigation in warehouses with a history of infestation
• Maintain regular cleaning protocols to eliminate food and harborage sources

✅ Conclusion

The Cadelle Beetle (Tenebroides mauritanicus) poses a serious threat to grain storage due to its long lifespan, hidden egg-laying behavior, and ability to survive in oxygen-limited conditions. An effective Integrated Pest Management (IPM) approach should include sanitation, routine monitoring, structural maintenance, and targeted control to ensure stored products remain safe and marketable throughout the supply chain.