Irregular Pine Scale. is the accepted common name. The scientific name is Toumeyella pinicola. Monterey pine is an especially favorite host, but seven other pine species are also attacked.
When irregular scale is present, you should also look for ant activity. Ants are shepherds for the scale because they want to harvest the honeydew the scale produces. In this regard, the ants will ward off predators and parasites of the scale, thus compounding the scale problem. Attention to ant control is important if good scale control is to be achieved. In old mature trees scale control can be difficult. Often times limiting ant access to the tree(s) will allow parasites to control the scale problem. If this is not possible, the application of a summer oil to the foliage should be made in March on the Central Coast. Young/small trees can be sprayed with a hand sprayer. Large trees will require the use of high pressure equipment, and the services of a professional applicator.