Reishi Mushroom Beetle (Cis chinensis): The Tiny Enemy Hidden in Medicinal Mushrooms

For those involved in cultivating or trading medicinal mushrooms like reishi, the Reishi mushroom beetle (Cis chinensis) is an insidious threat that’s often overlooked. Despite its tiny size — just 1.7 to 2.7 mm — this beetle can cause significant damage to valuable dried mushroom stocks, threatening both product quality and economic returns.

Anatomy & Biology: Small But Highly Specialized

• Common name: Reishi mushroom beetle (Cis chinensis Lawrence)
• Scientific name:Cis chinensis (Lawrence)
• Family: Ciidae
• Order: Coleoptera

Adult beetles are dark brown, with a body length roughly twice their width. The head is usually darker than the elytra (forewings), and their antennae, mouthparts, and legs are yellowish.

The thorax is smooth and lacks serrations along its edges, featuring small pits on its surface. The forewings are smooth with tiny scattered pits and cover the abdomen completely.

Complete Metamorphosis: A Rapid Lifecycle

The Cis chinensis undergoes complete metamorphosis, consisting of:

• Egg stage: 3–5 days. Females lay eggs in clusters, producing between 254–884 eggs.
• Larval stage: 16–31 days, with four molting phases.
• Pupal stage: 3–5 days.
• Adult stage: Males live 131–517 days; females live 108–427 days.

Favorite Food Source: Dried Reishi Mushrooms

This beetle primarily targets dried reishi mushrooms and dried lion's mane mushrooms.

Destructive Behavior: From Cracks to Total Devastation

Female adults lay eggs in cracks and crevices of dried reishi mushrooms. Once hatched, larvae immediately start feeding within the mushroom flesh, especially around the cap area.

After exhausting this region, they move to other parts, with both larvae and adults contributing to the destruction. The mushrooms become riddled with holes, covered in black dust from frass (insect excrement). Severe infestations can reduce the mushroom to mere hollow shells of the cap, rendering them completely unmarketable.

Global Spread

The Reishi mushroom beetle has been reported in the United States, China, Japan, and throughout Thailand, causing year-round damage to stored dried mushrooms.

Prevention & Control Strategies

Conclusion

The Reishi mushroom beetle may be tiny, but its impact on medicinal mushroom products is enormous. Without strict prevention and control, infestations can devastate valuable stocks and disrupt business operations.

Producers and distributors of dried mushrooms must stay vigilant, incorporating effective heat treatments and careful monitoring to protect these precious health products.