Agriculture Reference
In-Depth Information
CONTROL
No single rootstock is resistant to all nematodes, but several are resistant to one or more
types. Use manures and compost to improve soil health and vine vigor. Healthy, well-ir-
rigated vines are less susceptible to the effects of nematodes. There are several chemical
treatments for nematodes, but none that are acceptable for an organic vineyard.
Orange Tortrix
A bell-shaped, ½ in. flying insect most often found in coastal vineyards on the West
Coast. It feeds on shoots, leaves, and even grapes that have been left on the vine from
the previous year. The larvae burrow into growing fruit and make nests of webbing in the
cluster. A similar moth, garden tortrix, may be caught in traps but is not a grape pest. The
chevron pattern on orange tortrix has less contrast than that of the garden tortrix.
CONTROL
Close monitoring is recommended for this potentially serious larval pest. Inspect weeds
and vine shoots early in season after flower clusters become attractive to larvae. Encourage
beneficial insects, especially parasitic wasps and spiders. Clear weeds and remove mummi-
fied grapes from vines. Pheromone traps may be effective in midwinter. Treat with Bacillus
thuringiensis or spinosad.
