Bonsai Pests

Aphids

One such common problem is the aphid. Bonsai are definitely not immune. While working on a Podocarpus bonsai with a new client, I discovered a bad infestation of blue aphids. That’s right blue! If that surprises you read on.

(The following information is excerpted from a University of Florida, Institute of Food and Agricultural Sciences publication.) "'Aphids’ or ‘plant lice’ may infest almost any plant. Aphids have piercing-sucking mouth parts and cause damage by sucking the plant juices.

However, their ability to transmit plant virus diseases may be more harmful than any direct feeding damage."

That line alone made me pay more attention to aphids of all colors! As these red aphids indicate, they do come in many different colors.

"Aphids are soft bodied pear-shaped insects generally less than 1/8 inch long and usually green in color but many are black, brown, pink, yellow, blue, or white.

They are commonly found on the stems or undersides of leaves in clusters or colonies of individuals.

Most aphids are wingless but when colonies become overcrowded or the host plant becomes undesirable, winged forms are produced which establish new colonies.

The most distinguishing feature in the identification of aphids is the two short cornicles or tubes which extend from the end of their body. Aphids are unlike most insects in two ways: almost all are females and reproduce without mating, and they seldom lay eggs but give birth to living young. Aphids have the ability to reproduce rapidly and there are many generations per year."

In other words, check for bonsai plant pests on your trees frequently. This is an important aspect of growing bonsai.

"Aphids excrete large amounts of honeydew which provides an excellent medium for the growth of a black fungus called 'sooty mold’.

Besides being unattractive, sooty mold interferes with photosynthesis and can retard the growth of the plant. Sooty mold usually weathers away following management of the insect infestation."

A little scrubbing with an old toothbrush and soapsuds will also help remove sooty mold.

"Ants feed on the honeydew and when ants are observed, plants should be examined closely for these sucking pests."

If you have ants, you very likely have aphids. Aphids may be one of your most problematic bonsai pests, especially if you are an indoor grower.

Non-Insecticidal Management

"Many homeowners are able to remove aphids and keep populations below damaging levels by spraying their landscape plants with a forceful stream of water. Use a garden hose with an adjustable nozzle and spray undersides of leaves and stems.

Insecticidal soaps are available that are formulated for managing insects and related pests. If one of the commercial soaps is unavailable, 3-4 tablespoons of liquid dishwashing soap per gallon of water may be applied as a foliar spray to the plants. Soap is effective in managing aphids, safe for people and the environment."

Insecticidal Management

Spray the plants to the point of run-off. Be especially careful to cover the undersides of the leaves and all parts of the twigs thoroughly."

‘Welcome to a World of Little Suckers’

by Mr. Gordon Ramel. The site includes a detailed article on "Relations with Ants".

Ants are another one of those bonsai pests you should get to know.

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