Page 22 - Free State Summer 2022

TOTAL PLANT MANAGEMENT (Continued) armored scale without the very obvious welling that
occurs in soft scales. Armored scale in general lay upward
the same species exhibit different physical characteristics
not related to their sexual organs. of 100 to 300 eggs per female.
Whether it is an armored or soft scale, the stage that
Female scale retain the immature external morphology
even when sexually mature, a condition known as follows is called the crawler stage. The first instars of
neotenic. Adult males usually have wings (depending most species of scale insects emerge from the egg with
on their species) always with one pair. The males are functional legs and are informally called “crawlers”. They
present for a mere 12 to 24 hours, with the sole purpose of immediately crawl around in search of a favorable spot to
finding a female to mate. Female scale insects produce settle down and feed. In some species they delay settling
a pheromone odor that attracts the male. Upon finding down, but no longer than 12 – 24 hours. Sometimes they
a female mate, the male uses its antennae to drum on are blown away by wind onto another host plant, where
top of the female. If the female finds the beat alluring, they may establish a colony separate from the original
mating will occur. Several of the scales called soft scales colony,
do not produce males and the females reproduce without Identifying Scale
mating. This type of reproduction is called parthenogenic You can often distinguish the difference between an
reproduction.
armored scale and soft scale by trying to pry off the
For scale species with males, they will mate with a couple cover. With armored scale the outer cover is hard and if
of females and die shortly afterward of exhaustion,
depleting their energy reserves. The female has a longer
life, up to several months, as eggs continue to develop
within her. The length of survival depends on the species
and the time of the year it is; if she is an over-wintering
species, she will live until the next spring, at which time she
will lay eggs that will hatch the following fall, continuing
the generation. Some species have one generation per
year while others have multiple generations per year.
The same species in a southern climate may have more
generations than the same species-damaging plants in a
northern location. Scale insects in tropical areas can have
multiple and often overlapping scale generations year-
round.
Soft scale and Wax scales have their waxy covers
integrated into the body of the insect and cannot be
easily separated. Most soft scales in temperate climates
overwinter as immature females. Female soft scales tend
to be rather flattened in profile and oval in their perimeter
shape in winter. In spring or early summer her body will
swell as eggs develop in her body. This causes the waxy
cover to swell up in raised profile. Soft scales feed on the
phloem of the plant extracting plant juices. They feed
heavily as eggs develop, often excreting large quantities
of honeydew. This honeydew can be used for detection of
a soft scale problem on a plant.
For armored scale, some species overwinter as immature
but some overwinter as pregnant females ready to Heavy Japanese maple scale on container grown cherry tree
give birth in spring to summer. Eggs develop under the Photo: Lynette Scaffidi

22 SUMMER 2022 • Free State News