Description
Armoured scales (Diaspididae) are a family of insects in the order Hemiptera, with about 1,400 species, most of them pests of cultivated plants. They originate from Eurasia and North Africa but have now been introduced to other continents as well.
Armoured scales are small insects, up to a few millimetres long. Their bodies are flattened, and their legs, eyes and antennae are partly or completely reduced. They reproduce parthenogenetically or sexually. In some species the larvae hatch inside the female's body. After hatching, the larvae look for a suitable feeding site, then form a protective shield and lead a sedentary life. The males are winged insects.
Scale insects are recognised above all by the sticky, honey-like patches on the attacked plants. On closer inspection you will find brown caps (shields) that can be lifted off with a needle.
Control
They are best fought with products intended for aphids, applied three times at weekly intervals. If the scales have not attacked the plant too heavily, they can be scraped off with the tip of a knife and the plant sprayed with a soap-and-spirit solution.