TYPE HOSTS DESCRIPTION Cottony Cushion Scale - Icerya purchasi and actylopius sp. Helen Atthowe - Missoula County Extension Woody ornamentals Adult female scale has a fluted cottony egg sac secreted from the body of the scale. Juniper Scale - Carulaspis juniperi USFS - Missoula Montana Junipers. White, circular 1/16 inch in diameter. Crawlers emerge May - June. Lecanium Scale - Lecanium corni Helen Atthowe - Missoula County Extension Fruit and decidious trees, and shrubs. Crawlers are salmon colored and emerge May through June; there is one generation per year. The scale coverings are dark brown, dome-shaped, and smooth. Oystershell Scale - Lepidosaphes ulmi     Missoula County Extension Whitney Cranshaw, Colorado State University, www.ipmimages.org   Lilac, poplar, willow, privet, sumac, aspen, and green ash. Also fruit trees. Pale yellow, tiny crawlers emerge May - June. Scales are grey-brown and shaped like a miniature oyster. There is one generation per year. Pine Needle Scale - Chionaspis pinifoliae USFS - Missoula, Montana Conifers, especially Mugo pine. Crawlers are bright orange-red and emerge April - May, with one generation per year; scale is white and elongate.

LIFE CYCLE: Scales have piercing-sucking mouthparts and suck sap from plants much like an aphid. However, scales are covered with a waxy, protective covering during most of their life cycle which makes their control more difficult than aphids. They are found on branches, needles, and sometimes fruit.

Scales usually overwinter in the egg stage beneath the protective scale coverings. Eggs hatch and tiny crawlers emerge in the spring, usually May or June, depending on the weather. They crawl some distance before settling down and starting to feed. They begin to excrete a waxy covering which eventually becomes the protective covering.
Treat the CRAWLER STAGE.

CONTROLS:

Biological: Scales have many predators and parasites. Researchers at the University of Illinois report that white clover planted in landscape and Christmas tree plantings enhances the parasitoid wasp (Aphytes chilensi) that attacks pine needle scale (Chionaspis). Ground covers, in general, are important in natural scale control.

Cultural: Rub scale off plants by hand with a glove or toothbrush.  Prune off infestations. 

Chemical: Time oil or soap sprays to coincide with crawler hatch. Don't put dormant oil sprays on too early. Wait until buds have broken and 1st green tissue is showing. If scale has been a problem, a second oil (or soap) spray may be necessary once leaves are fully expanded. Add pyrethrum to the oil spray. Spray Neem oil at least once. Often, two applications of Neem oil, 7-14 days apart, are more effective. Remember oils and soaps can harm predators and parasites, so only spray if scale is a serious problem. For indoor plants spray insecticideal soap plus pyrethrum 2-3 sprays 7-10 days apart.