Managing Vineyard Insect and Mite Pests
Multicolored Asian Lady Beetle
The multicolored Asian lady beetle (Harmonia axyridis) is native to Asia but occurs throughout the Eastern United States and Southern Canada.
Symptoms
Beetles do not cause physical damage to grape bunches but will feed as a secondary pest after berry splitting or after bunch breakdown caused by Botrytis bunch rot, bird damage or grape berry moth (See Figure 22.20).
Life Cycle
Eggs are laid in clusters on the underside of leaves near aphid colonies. Aphids are the primary source of food for the beetle.
Monitoring
Early detection of movement of populations into vineyards can be accomplished by using yellow sticky traps.
Cultural Pest Control
One approach in controlling these beetles is to minimize fungal diseases and pest infestation of grape clusters.
Biorational Pest Control
Botanicals
Aza-Direct (azadirachtin) an organic insecticide derived from the neem tree also has repellent and “knock down” activity that temporarily stuns the beetles.
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Chemical Pest Control
There are several insecticides labeled for use against multicolored Asian lady beetle. Provado (imidacloprid) is labeled for use on grapes and has a very short pre-harvest interval (PHI). Imidacloprid is not considered a contact pesticide, but extremely low rates of this compound have demonstrated the ability to knock these beetles down but not kill them.
Applying Control Materials
Even though these beetles are observed in vineyards throughout the growing season, chemical control measures are not justified until 1 to 2 weeks before harvest. Early season control is not justified because adult beetles cannot directly damage, or penetrate grape skins.
