Scientific name: Lepisma saccharina Family: Lepismatidae Order: Zygentoma Risk level: Moderate Category: Insect
? What is a silverfish
The silverfish (Lepisma saccharina) is among the oldest insects on Earth; its form has remained unchanged for 300 million years. Its flattened, silvery-scaled body measures 12–25 mm and has three tail-like appendages. It avoids light and moves quickly when exposed. Its presence is a precise indicator of high indoor humidity.
Silverfish life cycle
It undergoes complete metamorphosis. Eggs are laid directly on food. The larvae are the damaging stage. A full generation takes 4–8 weeks, and multiple generations can develop in an infested store.
Where silverfish occur
They are found in food warehouses worldwide and are common in the Gulf, Saudi Arabia and Egypt, especially in warm stores.
Damage and risks associated with silverfish
They damage starchy materials, paper, silk and cotton. They pose a risk to archival collections, rare manuscripts and historical books.
Signs of silverfish
Adult insects may be seen around light sources; larvae and silk threads may be found in food (moths), along with droppings and hollow grains (weevils and beetles), or small white eggs on food surfaces.
Where silverfish are found
They occur in damp bathrooms and kitchens, under loose tiles, alongside pipes, and in dark, highly humid places. They flee into cracks as soon as exposed to light.
Silverfish control methods
Monitor with pheromone traps. Treat the warehouse with pyrethroids. Fumigate stored products with phosphine or methyl bromide. Physical control can use temperatures below 10°C or above 55°C. Rotate stock using FIFO.
Silverfish control products
Use pyrethroids in warehouses, phosphine (PH3) for fumigation, deltamethrin for residual spraying, and diatomaceous earth for grains.
Food-facility control requirements
FSSC 22000 V7: stored-product pests are high-priority; pheromone traps and weekly records are mandatory. BRCGS: finding stored-product pests in a product is a major non-conformance (NC).
A fact about silverfish
The silverfish is among the oldest living organisms on Earth, with no major evolutionary change. It is considered an example of “evolutionary stasis” (Bradytely), in which an organism remains unchanged for millions of years because its environment has not changed enough to require adaptation.
Frequently asked questions
Q: How do stored-product pests enter a facility?
A: Usually through incoming shipments. Carefully inspecting samples from each shipment and quarantining new purchases are essential steps.
Q: Is low temperature enough to eliminate stored-product pests?
A: Yes. Temperatures below 10°C for two weeks stop reproduction and kill the weaker life stages. Below −18°C for three days kills all stages.
