SUGGESTED COMMON NAME: cottony
maple leaf scale
FIELD DESCRIPTION: Female oval, slightly
convex, purplish, with yellow-brown mid-dorsal
keel. Body covered with flakes of clear wax, and
at maturity the female produces a white, ribbed
ovisac which is 2 or 3X the body length (Fig. 68).


Fig. 68. Pulvinara acericola, adult female with ovisac, DPI Photo
702514-20.

DESCRIPTION: (Fig. 69) Adult females ovate,
2.5-4.5 mm long, 1.0-4.0 mm wide. DoR-
suM-Derm slightly sclerotized with pattern of
closely spaced circular or oval clear areas; each
clear area contains a small bilocular pore (Fig.
69, H). Body setae (Fig. 69, D) rather stout,
bluntly pointed, scattered over dorsum. Sub-
marginal tubercles (Fig. 69, F) number 1-10
around body. Group of 10-30 disc pores in me-
dian area anterior to anal plates. Anal plates
triangular with all angles slightly rounded; sub-
discal seta, 1 seta removed some distance from
the apex. VENTER-Antennae 8-segmented. Legs
with tibiotarsal scleroses and free articulation.
Each spiracular furrow has 40-90 quinquelocular
pores (Fig. 69, N) in band 2 to 3 pores wide.
Multilocular pores (Fig. 69, 0) most with 10
loculi, in cluster around vulvar area and in


transverse rows on the abdomen, several near
each coxae. Larger tubular ducts (Fig. 69, R)
with large filament, scattered over entire venter.
MARGIN -Marginal setae (Fig. 69, C) rather
slender, most slightly curved, acute, bifid or fim-
briate. Spiracular setae in groups of 3, median
seta about 2X longer than laterals.
DISTRIBUTION: Map XXVI. AL, AR, CT,
DC, GA, IN, LA, MD, MI, MS, NC, NY, OK,
PA, SC, TN, TX, VA, WV. Foreign: southern
Canada.


 Map XXVI. Distribution of Pulvinaria acericola.

BIOLOGY: Baerg (1947) published a com-
prehensive paper on the biology of cottony maple
leaf scale in Arkansas. The life cycle is probably
very similar in Florida, modified slightly by the
milder temperatures. There is one generation per
year. Eggs are laid when the adult female is on
the leaves. After egg hatch, the nymphs settle on
the leaves. The 2nd instar nymphs migrate from
leaves to twigs before leaf fall, where they over-
winter. Rapid growth occurs in the spring, and
males can then be differentiated from the
females. In May, the adult males emerge, mate
and then die. The mated females migrate back to
the leaves to feed and lay eggs.
ECONOMIC IMPORTANCE: Parasites and
predators normally keep this scale insect in
balance, but occasionally heavy infestations in
Virginia cause early leaf drop and even the death