Problem Solver


Scale Insects


What is Scale?

Scale spend most of their lives as immobile adults under a coating, sucking the sap from stalks, leaves and stems.
Hard scale has an oyster like coating and is difficult to control. Soft scale are usually found on the mid-rib of leaves
and stalks of host plants. The most common type is white wax scale, seen as large patches of white waxy material
along the stems and shoots. The wax covers the insects which feed on the sap. Adult scale lays up to 1000 eggs that
hatch into crawlers. These crawlers move to a nearby feeding site where they set up home feeding on the sap of the
plant. It is at this crawler stage the scale is most vulnerable as there is no waxy coating to protect them.

What are the symptoms?

If your citrus tree is dropping leaves, twigs and branches are dying back, and/or the fruit is stunted or distorted.
If you’ve noticed small yellow spots appearing on your citrus leaves any of these symptoms may indicate an
infestation of citrus scale pests. Other signs are white patches on stems or pink or brown raised dome like
structures on leaves and stalks about 3-5mm. Sooty mould can also be present.

Yates® Nature’s Way® Citrus & Ornamental Spray is a ready to use, organically certified blend of pyrethrin (an extract from the pyrethrum daisy) and vegetable oil. Regular spraying on the undersides of the leaves (so it comes into direct contact with the scale) will help bring scale insects under control.

jul16-organicscale-main Scale-and-sooty-mould

NOTE: There are other different types of scale and some scale insects are host specific, such as rose scale, white palm scale, gum tree scale and tea scale (camellias.) Others attack a variety of hosts such as white wax scale occuring on gardenias and citrus; and cottony cushion scale occuring on figs, rose, magnolias, grevilleas and citrus.