How to Manage Pests
UC Pest Management Guidelines
False Chinch Bug
Scientific name: Nysius raphanus
(Reviewed 6/06, updated 4/14)
In this Guideline:
Description of the Pest
False chinch bug breeds in great numbers in grass or weedy areas, especially on London rocket, and may migrate into vineyards when these areas dry up or are plowed under and the pests search for green growth. Adults are gray and about 0.12 inch long. Nymphs are gray with reddish brown abdomens. When they migrate, they are mainly in the wingless stage, and consequently they migrate by walking. A number of winged adults are also present, but instead of flying they march along with wingless immatures.
Large numbers of nymphs and adults may suck plant juices and inject a toxin that causes vines to wilt and turn brown. Because of the great number of bugs involved and their toxic injections, all the leaves on border vines can be killed in a few hours. September and October migrations are also possible.
False chinch bugs are mainly a problem in spring if large numbers move into vineyards as vegetation in surrounding areas dries. They are only a sporadic problem but occasionally cause rapid and serious damage to young vines.
If false chinch bugs have been a problem in past years, disc under stands of London rocket and other host weeds about 3 weeks before budbreak in grapevines. Do not delay discing until after budbreak, for it may result in a heavy movement of bugs from the weeds to the vines.
Organically Acceptable Methods
Cultural controls are organically acceptable.
Monitoring and Treatment Decisions
If discing weeds was not done, and high populations of false chinch bugs are found on weeds at budswell or after budbreak, a treatment may be necessary. If nymphs are found moving onto vines, spot treat both vines and adjacent weeds. Bugs migrate mainly in one direction and the wilted vines along the edge of the vineyard will show the line along which they are moving. A chemical barrier about 30 inches wide can prevent further migration.
UC IPM Pest Management Guidelines: Grape
Insects and Mites
W. J. Bentley, UC IPM Program, Kearney Agricultural Research Center, Parlier