Pine Bark Adelgid – Pineus strobe

Pine Bark Adelgid (Pineus strobe)

Common Name: Pine Bark Adelgid

Latin Name: Pineus strobe


Adult adelgids are tiny, purple to yellow, and coated with white wax threads.

Nymphs (immatures) are similar to adults except for their size.

Nymphs are bare and golden at first. They quickly darken and start secreting white, waxy threads.

The eggs are around 3 mm extensive and range in colour from milky to light yellow-brown.

Host plant: 

Scots and Austrian pine are common host plants.


The pine bark adelgid (Pineus strobe) is found in North America, Europe, and the United States anywhere white pines grow.

Damages caused by 

A tree affected with pine bark adelgid may appear to have snow on its branches and trunk. Infestations seldom reach this point in the Christmas tree industry. If pine bark adelgid is present, the white, fuzzy mass will appear on buds, elongating candles, and needle bases. A nymph, a wingless, purple adult female (approximately 132 inches long), or up to 25 light yellow-brown eggs may be found in this clump. During the growth season, winged forms may be present.

Life history and habits:

Pine bark adelgids can overwinter at any stage, most commonly as immature females. In the late winter, development continues, and eggs are laid in the spring. These eggs grow in both winged and wingless forms. Individuals with wings go to other trees and begin eating. Wingless forms continue to feed on the tree and breed indefinitely. Every year, there are five or more generations.