The body then secretes a wax that, combined with old skins, hardens to form a white scaly cover. At maturity, the cycle repeats. San Jose Scales have two to three generations each year. Rose Scale has a similar life cycle, with eggs hatching in late May or June, and a second generation appearing in August. And once they choose a spot, they stay put.
Crawlers move from plant to plant only by wind, birds or fruit drop.
San Jose Scale is a major pest of fruit trees and can attach to developing fruit. When the fruit falls to the ground, the crawlers can move to nearby plants. On roses, they tend to be found on stems near growing tips. On fruit, the scale tend to cluster around the stem and blossom ends, and red rings in the fruit s skin will form around the scale, giving the fruit a spotted or mottled appearance. San Jose Scale can be found on many types of fruit trees, bush berries such as currant and gooseberry, and trees such as poplar, birch, lilac, alder, arborvitae, dogwood, maple, spirea.