Fourlined plant bugs feed on many herbaceous and woody ornamentals including currant, rose, forsythia, sumac, and viburnum. The nymphs are bright red or yellow, adults is yellow to yellowgreen. Both stages have four distinct black lines running the length of the body, hence their name.
This plant bug can be very destructive, especially to herbs and mint. It feeds first on the upper, tender foliage leaving distinct redbrown spots. These spots, the plant's reaction to enzymes injected into the leaf by the insect, can range from white to almost black depending on the host. Feeding by large numbers of plant bugs can produce large brown blotches and/or leaf distortion.
Females cut slits into the host plant and lay 6 — 8 eggs inside. There is 1 generation a year. It occurs during a 6 week period from late May — June.
Honeylocust plant bugs, are 3/16" long light green insects that cause honeylocust and black locust foliage to become discolored, stunted, or deformed. These insects do their damage early in the spring but the symptoms persist through the season. Severe infestation can even cause twig dieback. Adults occur from late May to early July. Eggs are laid in the woody tissue and over winter there.
On problem trees, watch carefully for signs of activity in the spring. Examine terminal foliage for presence of the insects. Treat when leaves first open with Insecticidal Soap, Dursban, Malathion, Sevin, or Tempo.
The tarnished plant bug over winters as an adult and becomes active when leaves first begin to form. This insect feeds on weeds, vegetables, fruit, flowers, shrubs, and trees. There are several generations each year. Adults, which have a distinct yellow "Y" on their backs, are good fliers and move about easily. Symptoms produced vary among the different hosts.