Deformed or Dwarfed Flowers Signals Tarnished Plant Bug
The tarnished plant bug, an active, green to brown insect sometimes attacks certain annual or perennial flowers. This 1/4 inch bug is mottled with markings of yellow, brown and black. Look for a black tipped yellow triangle on each of its sides. It and the four-lined plant bug suck the life from young shoots and especially buds, causing deformed or dwarfed flowers.
Tarnished plant bugs appear in early spring, becoming more numerous toward the end of summer. Marigolds and Impatiens are favorite targets. Spray them early in the morning, when they are least active with an insect product.
Using Natural Insect Repellents
There are several natural insect repellents that often kill plant bugs on contact, but then will create a bad taste for the critter and make it go someplace else to munch. Neem Oil Soap, Hot Pepper Wax, and Garlic Barrier all have this potential repellent capability when applied properly on the tops and the bottoms of leaves of the target plant. The repelling effect will last for several weeks to a month depending on the weather conditions. See the Natural Repellents in Yardener's Tool Shed.
Using Natural Insecticides
Neem oil soap is a natural insecticide that will kill plant bugs on contact and then repel new arrivals for about 2 weeks. Insecticidal soap is another natural insecticide that is effective in killing this pest. Pyrethrum is made from chrysanthemum blossoms and is quite effective especially when applied directly to the pest. Light horticultural oil is effective in smothering [insect]. Go to the Natural Insecticides section in Yardener’s Tool Shed for details on each product.
Using Synthetic Insecticides
The pyrethroid class of insecticides are effective in controlling plant bugs. Go to Yardener's Tool Shed to check out the options in the Synthetic Insecticides section.