''Pulvinaria innumerabilis'' (cottony maple scale) is a small, flattened, brown

scale insect Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than the ...

about 1/8" long. In early summer mature females begin to secrete white, waxy, cottony-appearing egg sacs in which they lay as many as 1,500 eggs. Severely infested trees look like they are covered with strings of popcorn. ''P. innumerabilis'' can be found on all species of maples ( ''Acer'' spp.) but have a strong preference for silver maple. It is also known to be able to survive on

honey Honey is a sweet and viscous substance made by several bees, the best-known of which are honey bees. Honey is made and stored to nourish bee colonies. Bees produce honey by gathering and then refining the sugary secretions of plants (primar ...

and black locust, white ash, burning-bush,

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

boxelder ''Acer negundo'', the box elder, boxelder maple, Manitoba maple or ash-leaved maple, is a species of maple native to North America. It is a fast-growing, short-lived tree with opposite, compound leaves. It is sometimes considered a weedy or inv ...

dogwood ''Cornus'' is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous trees or shrub ...

, hackberry, sycamore,

beech Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...

elm Elms are deciduous and semi-deciduous trees comprising the flowering plant genus ''Ulmus'' in the plant family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of North ...

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...

basswood ''Tilia americana'' is a species of tree in the family Malvaceae, native to eastern North America, from southeast Manitoba east to New Brunswick, southwest to northeast Oklahoma, southeast to South Carolina, and west along the Niobrara River to ...

, and poplar.

Damage symptoms

While conspicuous, ''P. innumerabilis'' infestations usually have little impact on established trees. However, in large numbers they can cause premature leaf drop and twig dieback. Heavy infestations can cause leaves to turn yellow to light green and may cause stunted leaf growth.

Gallery

References

* * Insects described in 1854 Hemiptera of Asia Coccidae {{Coccidae-stub