Hibiscus syriacus Pests
Root Knot Nematodes (Meloidogyne
spp.): "Knots or galls form on roots causing the plant to be inefficient
in absorbing water and nutrients. Leaves are small and the plants fail
to make normal growth. Use caution when planting to be sure that planting
stock is not infested. If yard soil is contaminated, plant shrub in a large
container of sterilized soil. This is probably the most serious problem
experienced by althea."
"may cover the leaves with sticky honeydew. Use sprays of Sevin,
rotenone, acephate or malathion. The insects can also be dislodged
with high pressure water sprays from the garden hose." MSU
Melon aphids and mummy, courtesy of University of California, Davis.
japonica ) "are particularly fond of the flowers. Use sprays of malathion,
rotenone, Sevin or methoxychlor to control the adult beetles. The grubs
in the lawn can be controlled with diazinon or milky spore disease."
courtesy of Iowa State University.