such as other species of maple, basswood, white ash, boxelder, 
dogwood, honey and black locusts, hackberry, sycamore, beech, 
elm, willow, and poplar. The female is pale to dark brown, bare, 
convex to oval in shape, has a more or less distinct median ridge, 
and is about 4 to 6 mm. long. They are most conspicuous during 
the summer when large, white, cottony egg sacs extend from the 
rear. Males are flat, winged, and much smaller than the females. 
Eggs are laid from April to June in cottonlike masses under 
the female. These masses are several times the size of the scale. 
As a result, the rear of the scale is often elevated at an angle to 
the twig (fig. 27). Hatching occurs in June and July in the more 
northern States. Young larvae crawl to the undersurfaces of 
leaves and feed on the principal veins. They become mature in 
August and September and mate. The fertilized immature females 
crawl back to the twigs and small branches where they over- 
winter. Development is resumed in early spring and the females 
become mature by April. 
F-504123 
FIGURE 27.—The cottony maple 
é scale, Pulvinaria innumera- 
vb bilis, on twigs and leaves of 
soft maple. 
o 
: % 
eae ny 
Damage to heavily infested maples may be severe. Branches are 
killed, the foliage turns a sickly yellow, and the vigor of the tree 
is reduced. Such trees are then frequently attacked by other 
species of insects and further damaged. Honeydew dripping from 
infested shade trees on sidewalks, automobiles, or people is often 
a nuisance. Sooty mold developing in the honeydew also detracts 
greatly from the attractiveness of the trees. Fortunately, trees 
are seldom attacked heavily for two successive years. Insect pred- 
ators, including the dipteron, Lewcopomyia pulvinarie, larvae of 
the lepidopteron, Laetilia coccidivora, and the coccinellids, Chilo- 
corus bivulnerus and Adalia bipunctata sometimes play a primary 
role in the suppression of heavy populations. 
Pulvinaria acericola (Walsh and Riley), the maple leaf scale, 
feeds on soft and sugar maples throughout most of the Eastern 
States and in southern Canada. Female scales are dark purple, 
have a brownish-yellow mid-dorsal stripe and three rows of small 
waxy spots on each side, and are about 5 mm. long. The body 
usually bears tiny tufts of white, cottonly filaments and a long 
cottony egg sac at the posterior end. 
Partly grown nymphs spend the winter on the branches of the 
host. Growth is completed in the spring. Males appear first and 
102 
