Cottony Cushion Scale – Definition & Detailed Explanation – Tree Diseases and Pests Glossary

I. What is Cottony Cushion Scale?

Cottony cushion scale, also known as Icerya purchasi, is a type of scale insect that feeds on the sap of plants. These insects are named for the fluffy white cotton-like substance they produce to protect themselves and their eggs. Cottony cushion scale insects are typically found on the stems, leaves, and fruit of a variety of plants, including citrus trees, ornamental shrubs, and houseplants.

II. What are the symptoms of Cottony Cushion Scale infestation?

The presence of cottony cushion scale insects can often be identified by the white, cottony masses they create on plant surfaces. In addition to the visible cottony substance, other symptoms of infestation may include yellowing or wilting of leaves, stunted growth, and a general decline in plant health. As the insects feed on plant sap, they can also excrete a sticky substance called honeydew, which can attract ants and promote the growth of sooty mold.

III. How does Cottony Cushion Scale spread?

Cottony cushion scale insects can spread through various means, including wind, birds, and human activity. They can also be transported on infested plant material, such as cuttings or nursery stock. Once established on a plant, cottony cushion scale insects can reproduce rapidly, with females laying hundreds of eggs at a time. These eggs hatch into mobile crawlers that can move to other parts of the plant or be carried to new plants by wind or other means.

IV. What are the potential risks of Cottony Cushion Scale infestation?

Cottony cushion scale infestations can pose several risks to plants and ecosystems. In addition to causing direct damage to plants by feeding on their sap, these insects can also weaken plants and make them more susceptible to other pests and diseases. The honeydew excreted by cottony cushion scale insects can attract ants, which can protect the insects from natural predators and further damage plants. Additionally, the growth of sooty mold on honeydew-covered surfaces can interfere with photosynthesis and reduce plant vigor.

V. How can Cottony Cushion Scale be controlled and treated?

There are several methods available for controlling and treating cottony cushion scale infestations. One common approach is to physically remove the insects by hand or with a strong stream of water. Insecticidal soaps or horticultural oils can also be effective in controlling cottony cushion scale populations. Biological control agents, such as ladybugs or parasitic wasps, can be introduced to help manage infestations. In severe cases, chemical insecticides may be necessary, but these should be used as a last resort and with caution to minimize harm to beneficial insects and the environment.

VI. What are some preventative measures against Cottony Cushion Scale?

To prevent cottony cushion scale infestations, it is important to practice good plant hygiene and regularly inspect plants for signs of pests. Avoid over-fertilizing plants, as this can attract scale insects and other pests. When purchasing new plants, inspect them carefully for signs of infestation before bringing them into your garden. Prune and dispose of infested plant material properly to prevent the spread of insects. Encouraging natural predators, such as ladybugs and lacewings, can also help keep cottony cushion scale populations in check. By taking these preventative measures, you can help protect your plants from the damaging effects of cottony cushion scale infestations.