reported on peach (28). In late spring, from 50 to more than 2,000 white eggs are 
laid beneath the body of the adult female. The number of eggs is generally 
proportional to the size of the adult female. In early summer, eggs hatch and first 
instars move principally to the undersides of the leaves, although a few settle on the 
stems. In late summer or early fall, molting occurs and the resultant second instars 
move from the leaves to rough areas of branches, where they overwinter. In early 
spring, second-instar females grow rapidly, molt, and develop into adults. Males 
may be present or absent, apparently depending on the host or environmental 
conditions (426). The European fruit lecanium normally does not kill trees but 
produces a large quantity of honeydew which, when contaminated with sooty mold, 
covers the plant with an unsightly black film. The species is sometimes a serious 
pest of plums, apricots, and other fruit trees. Over 40 natural enemies have been 
found associated with the European fruit lecanium, including fungi, lady beetles, 
and chalcidoid wasps. Some of the parasitic hymenopterans are effective control 
agents. 
The cottony maple scale, Pulvinaria innumerabilis (Rathvon), is apparently 
native to North America and is known from nearly every State in the United States. 
This soft scale prefers maples, particularly silver maple, but is reported on a large 
number of important hosts, including basswood, ash, dogwood, hackberry, locust, 
sycamore, hawthorn, pear, oak, poplar, elm, willow, apple, peach, plum (fig. 32). 
The cottony maple scale is found in natural habitats and ornamental plantings. 
Adult females have variable color patterns but are generally reddish brown, and 
have a median ridge. The ovisac is one to two times longer than the adult and is 
produced by the raised, ventral abdomen. 
Courtesy Can. For. Serv., 
Can. Dep. Environ., Sault Ste. Marie, Ont. 
Figure 32.—The cottony maple scale, Pulvinaria 
innumerabilis, on twigs and leaves of soft maple. 
The cottony maple scale has one generation per year (/3/0) and overwinters as 
mated, newly mature, adult females on the twigs and branches of the host. The 
literature often refers to the overwintering stage as immature females, but slide- 
mounted specimens collected during the winter show that the species overwinters as 
97 
