Cercospora leaf spot, Cercospora spp.
Cercospora leaf spot generally is not a serious disease of leucothoe. However,
in years with a cool, rainy spring, Cercospora leaf spot can be a disfiguring
disease problem. Leaf spots are usually red in color, and start small, but they
may enlarge and coalesce to cover large areas of the leaf surface. In severe
instances, foliage may drop from the plant.
Control can be achieved by raking and removing fallen leaves in autumn to
reduce the overwintering inoculum capable of infecting new growth in spring.
Chemical control is usually not necessary. However, fungicide sprays can be
applied when new growth appears in spring. Several applications may be
necessary during periods of extended wet weather. Among the compounds
registered for use in Connecticut are chlorothalonil, mancozeb, and
thiophanate-methyl. Consult the label for dosage rates and safety precautions.
Andromeda lace bug,Stephanitis takeyai.
This lace bug feeds on the Japanese Andromeda, Pieris japonica, and
occasionally on Azalea kaempheri but rarely if ever on other broadleaf
evergreens, including P. floribunda. Both adults and nymphs suck the sap
from the undersides of the leaves, causing a mottling or blanching. The adult
lace bug is about 1/8" long. The head covering and markings on the
sculptured wings are intensely black. Eggs overwinter in the undersides of the
lower leaves. There are three or four generations each year. Among the
compounds registered for control of this pest in Connecticut are malathion,
insecticidal soap or imidacloprid. When needed, malathion or insecticidal soap
can be applied where nymphs are feeding during the last week in May, just after
eggs have hatched. Imidacloprid, applied as a soil drench, gives systemic,
season-long control of this insect. Consult the label for dosage rates and
Content Last Modified on 4/10/2007 2:36:53 PM
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