BEST PLANTS, BEST PRACTICES

A guide to conservation planting for Napa County and beyond

INSECTS

 
To find out what insects are associated with a particular plant, go to .

Choose a Practice, and press the SEARCH button. Click on the scientific name of a plant, and a detail panel opens up, showing photos. There are also links for more information about this plant. Click on the Associations link, and you will go to a Calflora page that shows any known information about insects that like this plant -- both pollinators and pests.

For example, here are the association pages for sulphur buckwheat, Eriogonum umbellatum, and mountain pride, Penstemon newberryi.

Euphydryas chalcedona, Variable Checkerspot © 2008 Ron Wolf (CalPhotos)

 

Pest Predators and Pest Parasites

Excellent information on pest predators and parasites is available on the UC Integrated Pest Management website. Pest predators are apparently attracted to the presence of pest insects rather than to specific plants. Some, such as Syrphid (hover) flies, feed on pollen as adults (and thereby act as general pollinators), but feed on soft bodied insects (aphids) in the larval stage.

Syrphid Fly ©2011 Gary McDonald (CalPhotos)

 

Planting for Pollinators and Beneficial Insects

A strategy for attracting pollinators and other beneficial insects involves planting so as to provide sources of pollen year round. On the Plants for Projects page, plants are displayed with their bloom periods. This should make it possible to choose plants to cover the whole year. For instance:

Amorpha fruticosa
western false indigo
Feb - Apr
Ceanothus thyrsiflorus
blueblossom
Mar - May
Eriodictyon californicum
Yerba santa
May - Jun
Eriogonum fasciculatum
California buckwheat
Jun - Aug
Grindelia camporum
gumweed
Aug - Oct
Baccharis pilularis
coyotebush
Oct - Jan

 

Pests

Among the worst pests facing grape growers is the glassy-winged sharpshooter, because it can spread Pierce's disease (see this note from the CA Department of Food and Agriculture). The causal bacterium, Xylella fastidiosa, lives in other plants (including many native plants), and sharpshooters can spread the bacterium from those plants to grapevines, or from one grapevine to another. From this point of view, care must be taken to ensure that both plants which host the baterium and plants which host the sharpshooter are not growing too close to a vineyard.

Grape whitefly is another vineyard pest which is hosted by coffeeberry, hawthorn, and wild native grapes.

European grapevine moth is another vineyard pest recently arrived in Calfornia, known to be hosted by several Prunus species and olive trees.
 

References

butterflies
Art Shapiro's Butterfly Site (ASB)
Butterflies and Moths of North America (BMNA)
 
native bees
The Xerces Society (XERCES)
Las Piltas Native Plant Nursery / Bees
 
hummingbirds
Las Piltas Native Plant Nursery / Hummingbirds
Hummingbirds.net / California
 
pollinators in general
Pollinator Biology and Habitat in California NRCS Biology Technical Note, 2009
Pollinator Partnership
UC Cooperative Extension Pollinator Information
The Xerces Society (XERCES): Pollinator Conservation
 
other beneficial insects (pest predators and parasites)
UC Integrated Pest Management (UC-IPM) Natural Enemies Gallery
Hedgerows enhance beneficial insects on farms in CA's Central Valley
  Morandin, Long, Pease, and Kremen, 2011
The Xerces Society (XERCES): Conservation Biocontrol
Plants that Attract Beneficial Insects Fred Hoffman
Organic Insect Control with Beneficial Insects... Wayne Green
 
pests
Grape Pest Management Guidelines including Insects and Mites UC Integrated Pest Management
Insects and Mites UC Integrated Viticulture
The Glassy-winged Sharpshooter as a threat to vineyards Napa County Agricultural Commissioner
Riparian Plants and Pierce's Disease College of Natural Resources, UC Berkeley
Creating Green Sharpshooter Barriers to Stop the Spread of Pierce's Disease
  California Department of Food and Agriculture
European Grapevine Moth UC Integrated Pest Management

California Oak Mortality Task Force (OMTF) (Sudden Oak Death)