Insect
and Disease Fact Sheet Compliments of New Century
1-877-79TREES
Euonymus Scale
Hosts:
Euonymus
(Unaspis euonymi), camellia.
boxwood, bittersweet, daphne, eugenia,
English ivy, hibiscus, holly jasmine, privet, honeysuckle, olive, pachysandra
and stonefruits (Prunus
sp.) are reported hosts of this scale.
Description:
Heavy
infestations are clearly visible from some distance away. Affected foliage
appears to have small white cottony spots. Leaves eventually turn yellow and
die as feeding continues. Males are white and elongated and females are brown
and oval shaped and about 1/16 inch long. Large numbers congregate on the
undersides of leaves, twigs, and stems. About 60 days are required to complete
a generation. There may be two generations per year.
In the
spring, over wintering females lay eggs that hatch in late May or early June.
This period usually occurs when fringetrees, (Chionanthus), cockspur hawthorn (Crataequs
crusgalli), Beautybush (Kolkwitzia)
and Late Lilac (Syringa villosa)
are in bloom.Crawlers move to leaves and stem and
begin to feed by sucking plant juices. Maturing males prefer leaves and females
congregate on stems.
|
Recommendations: A
dormant spray in early spring before the buds have started to open will
decrease the scale population but also may defoliate the plant. New leaves
will rapidly replace those lost. Apply labeled insecticides such as carbaryl (Sevin), malathion or acephate (Orthene or Isotox) to control
crawlers in late May or early June. Reapply as needed in late August to early
September to control second generation crawlers. Control
is probably impossible for Euonymus that has been heavily attacked and is in
very poor health. Therefore, complete removal and destruction of the infested
plants (including roots) is suggested. |
Lifecycle of Euonymus Scale. |
Information obtained through
Kansas State University
Insect
and Disease Fact Sheet Compliments of New Century
1-877-79TREES