Honeylocust Plant Bug

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Pest Identification & Damage

Common Name(s):
Honeylocust Plant Bug

Scientific Name:
Diaphnocoris chlorionis (Say), Hemiptera: Family Miridae.

Identifying Characteristics for Damaging Stage(s):

Adult bugs are about 1/4 inch long and either pale green or tan in color. Nymphs are also pale green.

Damage/Nature and Symptoms:

The HLPB is a sap-sucking insect with piercing-sucking mouthparts which damages plants by injecting a toxic saliva when it feeds. This salivary toxin kills cells around the feeding site and results in a yellow spot which enlarges somewhat as the toxin moves laterally, eventually creating a brown spot. Damage in early spring results in leaf rolling, distortion and stunting. In some cases lateral shoots may be killed outright. Damage does not go away, but is present throughout the summer. Both honey and black locust trees may be attacked.

Honeylocust Plant Bug Damage

Distribution and Life Cycle

Distribution:

The HLPB is generally distributed throughout the eastern U.S., and is common in eastern NE. Apparently it has been introduced into California as well.

Summary of Life Cycle:

HLPB winters as eggs on honey and black locust trees and these hatch in April and May. Nymphs require about a month to mature and adults can be found on trees through July. Eggs are laid in midsummer and these overwinter to hatch the following year. There is a single annual generation.

Management Methods:

Inspection/Survey Methods:

Examine honey and black locust trees carefully in the spring, looking for young nymphs and early signs of stippling and distortion of emerging leaves.

Non-Chemical Management Strategies:

Many young nymphs may be knocked off leaves of small trees by spraying them with a stream of water from the garden hose at high pressure.

Chemical Management Strategies:

Consider treatment of young trees if damage is apparent. Larger trees should withstand a year or two of damage without serious harm. Use insecticidal soaps in early spring after young nymphs appear. Also consider using an insecticide, applying at least two spray treatments to prevent feeding and leaf damage. Be sure to cover foliage and bark surfaces well.

For the latest information on available chemical controls, consult the Pesticide Selection Guide.

References:

Metcalf, C. L., W. P. Flint and R. L. Metcalf, 1962. Destructive and Useful Insects. 4th Ed.: McGraw-Hill Book Co., New York NY. 1087 p.

Baker, W. L., 1972. Eastern Forest Insects. USDA Forest Service Misc. Pub. No. 1175, US Forest Service, 642 pp.