Lecanium scale Figure 3. San Jose scale Figure 4. In Ontario, San Jose scale is the most serious scale pest. These insects are soft-bodied homopterans. Female scales do not lay eggs but give birth to living young.
Crawlers are minute, orange-yellow and oval, with six legs and one pair of antennae.
Sexes are differentiated by body form and shape of the wax exuviae. Adult female San Jose scale with shell removed. In contrast, the females are dark yellow with an oval shape tapering to a point at one end. The outer shell of female San Jose scale remains relatively circular with a nipple, while male exuviae is elongated with the nipple offset to one end, while oyster-shell scale are elongated. The females are nearly round and about 1.6mm across with a raised nipple in the centre, and they remain under their scale coverings their entire lives.