The Aphid

We will start with the most troublesome little critter, the Aphid. In warm, humid weather, this little guy reproduces at an alarming rate of speed. They will eventually cause widespread smothering and disfigurement of your plant.

During the early part of autumn, eggs from the summer Aphids will be laid on the branches and bark of plum and cherry trees. Hatching in the springtime, the winged female will fly to the host plants in your pond. Here they live like happy campers, reproducing and giving birth to live wingless females. The bad part is they continue this cycle every few days and infest quickly.

To eliminate or reduce this process, spray your trees with a dormant oil winter spray. Only do this when your trees are in winter dormancy. If you are infested in the summer, the only way to get rid of them is to shoot clear water from a hose. This knocks them off into the water were all manner of other creatures and your fish devour them. Some may crawl back on, but eventually this method will help to rid them from the pond.

The Waterlily Beetle

This little fellow is one of the more destructive little pests that you may have to deal with in your pond. He is called The Waterlily Beetle because he only cares about the succulent waterlilies in your pond. You can spot him as small dark brown beetles on your lily pads. The larvae are shinny black in color. They will strip away the leaves in short order along with the blooms and stalks.

The adult hibernates in pond-side vegetation in the winter and emerges usually in late spring when the lily pads start to reach the surface of the water. They finally migrate to the lilies and deposit eggs on the leaf surface, ready to begin the cycle of life.

Sadly, there is not much you can do to stop them. Shooting them into the water with a garden hose will make a tasty snack for your fish, but won't rid the pond of the problem. Clearing away marginal vegetation during autumn will help. Removing their winter home will help keep down the population in spring. The only other solution is to hand pick, yes hand pick them of and destroy them. Not a fun job, but it may be necessary to reduce the population.

Brown China Moth

Here is another pest that can destroy your waterlilies in short order. To the eye, it just looks like any other moth flying around, but this pest is looking for a quick meal. He will eventually shed the floating leaves and in turn, make a shelter for itself, sticking two pieces of leaf together making a cocoon. They are easily spotted because of their grayish color and silky consistency.

This moth lays her eggs on the underside of the floating leaves during the summer months. Caterpillars emerge and burrow into the undersides of the juicy foliage. Small infestations can be removed by hand, but net out any floating debris or caterpillars that are floating in the water.

Caddis Fly

The Caddis fly produces larvae that feed on the foliage of aquatic plants and live totally submerges in the larvae stage of life. Eggs are laid in long strings, usually around aquatic plants. Once again, ridding the pond of them is difficult. Fish will help you, but picking them off by hand is the only other cure.

Pond Snail

The Ramshorn and Japanese trapdoor snail are rarely destructive in nature. But, some species like the greater pond snail or freshwater whelk can be very destructive. Aquatic plants with floating foliage are the most vulnerable. Usually, the snails with tall pointed shells are the most destructive. These lay eggs in cylinders of jelly that attach themselves to your plants.

If you have a problem in a small confined area like a barrel pond or small pre-form pond; you can add aquatic snail killer to the water. This however is impractical for a larger pond. You may want to place lettuce leaves in the pond and allow them to float overnight. In the morning gather them with a net and destroy the snails on them.

Waterlily Leaf Spot

There is generally to varieties of leaf spot that damage your waterlilies. One appears an as dark spot on the leaves which eventually rot through them. The other starts at the leave edges and causes them to turn brown in color.

You should remove the damaged leaves and discard them as soon as you see the problem appear. In ponds with NO fish, you can add copper fungicide, like Bordeaux to the water to take care of the problem.

Waterlily Crown Rot

Two different types of crown rot are caused by two different organisms. Healthy plants suddenly develop blackening of the leaves and flower stems and become soft and rotten. Then the rootstocks start to smell and turn into a jelly consistency.

You should remove all infected plants and destroy them and the soil they were in. Do not use the soil or pots to replant as they to will become infected. The pond then needs to be cleaned by swirling a muslin bag filled with copper-sulfate crystals through the water. REMOVE ALL FISH before beginning this treatment and DO NOT return them until the pond has been drained, rinsed out and refilled.

The more recent strain of crown rot is caused by a number of pathogens. It is believed that this problem originated from the Far East on imported waterlilies. It eventually turns the crowns into a brown mass. There is NO cure for this strain. The best thing you can do is remove and destroy the plants. Then the pond should be cleaned thoroughly with a solution of sodium hypochloride before being flushed out with clean water. Once clear water is run back in, new plants can be introduced to the pond.