Pond Pests – What Every Pond Owner Should Watch Out For

A well-maintained pond is surprisingly resilient to pests and diseases, but occasional problems can arise. Knowing what to look for and acting quickly can prevent minor issues from becoming major headaches.

Rodents and Pond Liners

Many pond owners are unaware that rodents can sometimes damage pond liners. Although uncommon, there have been reports of voles and other burrowing rodents gnawing through liners, causing frustrating leaks and water loss.

If voles are known to be present in your area, it is worth taking preventative measures during pond construction. Installing a plastic-coated wire mesh beneath the pond liner can provide an additional layer of protection against sharp teeth and burrowing activity. A good quality underlay will also help protect the liner from both animal damage and sharp objects in the ground.

Inspect New Pond Plants Carefully

Many pond pests arrive as unwelcome hitchhikers on newly purchased aquatic plants. Before introducing plants to your pond, inspect leaves, stems and baskets carefully for eggs, insects or signs of damage.

Quarantining new plants for a few days can help prevent pests from spreading throughout the pond.

Water Lily Aphids

Water lily aphids are among the most common pond plant pests. These small dark brown or black insects cluster on the undersides of floating leaves and feed on plant sap.

A heavy infestation can cause leaves to yellow, curl or become distorted. Fortunately, aphids can usually be controlled without chemicals. A strong jet of water directed at affected leaves is often enough to dislodge them. Avoid using pesticides, as even products marketed as natural can be harmful to fish, amphibians and beneficial pond insects.

Water Lily Beetles

Water lily beetles can cause significant damage to water lilies if left unchecked. Adult beetles lay eggs on the leaves, and the emerging larvae feed on the foliage, creating holes and skeletonised patches.

Regular inspection of water lily leaves is the best form of control. Remove any eggs, larvae or heavily damaged leaves as soon as they are discovered to prevent the infestation from spreading.

Leaf-Mining Larvae

Small fly larvae can sometimes tunnel between the surfaces of water lily leaves, creating distinctive winding trails. While usually not fatal to the plant, repeated attacks can weaken it and spoil its appearance.

Removing affected leaves promptly is usually sufficient to keep the problem under control.

Pond Snails – Friend or Foe?

Many new pond owners worry about finding snails on their aquatic plants. In reality, most pond snails are beneficial. They feed on algae, dead plant material and organic debris, helping to keep the pond clean.

Only in very large numbers can snails become a nuisance, and even then they are rarely harmful to healthy pond plants.

Regular Checks Prevent Problems

The best defence against pond pests is regular observation. Spend a few minutes each week checking your plants for signs of damage, discoloured leaves or unusual insect activity. Early intervention is usually all that is needed to prevent serious problems.

A healthy pond with a good balance of plants, wildlife and water quality will naturally resist most pest issues, allowing you to enjoy your pond with minimal maintenance and maximum enjoyment.