Control Chrysanthemum Insects
Aphids suck plant juices and are controlled with applications of Diazinon dust or sprays of rotenone, Sevin, malathion, Diazinon, or Orthene.
Rose chafers feed on the mums and are most common where soils are sandy. These are light tan with red spindly legs. Pesticides generally do a poor job of controlling rose chafer due to the large numbers of insects present at one time. Insecticides which may be used are Sevin, methoxychlor, or rotenone.
Stalk borer bores in the stem of chrysanthemum at flowering time. No chemical control is listed.
Four-lined plant bug causes sunken, round, brown spots on the leaves. No chemical control is listed.
Chrysanthemum leaf miner makes irregular tunnels in the leaves near the margins. Use applications of Orthene.
Chrysanthemum lace bug sucks plant juices giving the leaves a bleached out appearance. Spray with Orthene or methoxychlor.
Mites cause the leaves to lose their good green color. If the infestation is heavy, fine webbing may be seen at the branch tips. Spray with rotenone.
The foliar nematode causes yellowish brown spotting of the leaves. The spots are more or less bounded by larger veins. The spots enlarge and run together so the entire leaf is involved. The leaves die, become brittle and fall. The brown areas in the leaf are usually wedge shaped. Where the pest is a problem, propagate plants from cuttings taken from tall shoots and not by division. Do not replant the cuttings in the same area. The bed should be mulched when the soil has warmed. No chemical control is listed.