California’s Butterflies

Nectar Plants

Nectar Sources

Another way to tell which species occur in your area is to set up nectar sources and draw butterflies to your yard.  Local butterflies will be attracted to these nectar sources.  Some of the things that need to be kept in mind when searching for good nectar sources are:

 

             1) identify which native plants will produce high quantities of nectar,

             2) plants that exhibit good color, 3) identify plants that occur in your local area, and

             3) identify plants that bloom at different times of year. 

 

When looking for nectar sources you should look for plants that will provide nectar to butterflies throughout the spring and summer.  Most plants only bloom for a month or so.  A combination of plants will be needed to provide nectar to butterflies throughout the season.

 

Good native nectar sources that will, in combination, provide nectar throughout most of the season are Eriodictyon species, Asclepias species, Encelia virginiensis, Bebbia juncea, Chrysothamnus nauseosus, Baccharis salicifolia, Eriogonum fasciculatum, and Ericameria linearifolia.  A good non-native species is Lantana, which can be obtained from many nurseries.  I prefer the orange/red varieties since they seem to be more attractive to butterflies.  The reason this plant is good as a nectar source is that the flowers are not deep and do not require a long proboscis to obtain the nectar.  This Lantana produces many flowers and booms pretty much throughout the year.

 

Once you determine which butterflies occur in your area you can come up with a list of plants which will support the larvae of these butterflies.  Dr. Pratt has developed a list of plants which most of our southern California butterflies will use as food plants (see Food Plants page).  This table is not complete and does not reflect the actual complexity of larval food plants.  For instance, Satyrium auretorum feeds on oaks.  It prefers scrub oaks in most areas such as Quercus wislizenii, but in the Santa Monica Mountains it is found using Quercus agrifolia, an oak species that the butterfly does not appear to use elsewhere.  Another oak that is not thought to be a food plant for Satyrium auretorum is Quercus chrysolepis, yet this oak is used along the eastern slopes of the Sierra Nevada.  A good source for native plants is the Theodore Payne Foundation website at www.theodorepayne.org.

 

Many butterflies that feed on lupines use specific perennial species in specific areas.  One of the most frequently used lupine is Lupinus excubitus.  In some cases the presence of ants is even more important than the actual lupine species.  For instance, Lupinus magnificus is not normally used by Icaricia icarioides but where there are incredibly high numbers of a Formica, an ant species in the Coso Mountains, Icaricia icarioides is found using this lupine.

 

There are two extremes of yard butterfly habitat types.  One is a habitat within a neighborhood of small yards with neighbors with largely lawns and non-native plants.  The other is a yard within multiple acre zoning and a largely open natural habitat.  With the first type you do not have to consider the effects of bringing in the wrong varieties of California species, since there will not be local plants that will exchange genes with your plants.  But if you have a yard that adjoins native habitat with a high diversity of native plants you have to consider the risk of bringing in the wrong plants to the area.

 

The wrong varieties of plants can be bad for local insects, particularly if they are not adapted to these varieties.  When possible you may try to collect the seeds from local plants.  These seeds can require specific conditions to get them to germinate.  Many legumes, for instance, require cutting of the seed coat.  Once the seed coat is broken the seeds can be placed on a wet paper towel to get them to germinate.  The seeds will then soak up water and can then be planted.

 

Many other plants require cold to get them to germinate.  Most species will start to germinate after about a month of refrigeration on wet paper toweling, but some particularly high elevation or cold adapted species will require longer periods.  Once germinated these plants need to be grown in pots.  If you put them out they will often be eaten at this stage.  Seedlings are highly attractive to many herbivores, particularly rabbits.

 

Seeds of other plants in southern California respond to fire.  Once fire has cleared an area, it provides open habitat for new plants.  Therefore, plants have to respond to fire in different ways.  The buckthorns (Ceanothus species) require fire on the seeds to induce sprouting.  Boiling can mimic the effects of fire and help induce sprouting.  As another example, fire opens the cones of the Tecate Cypress and allows the seeds to drop out and germinate.

 

Once the plants are well established in the pots you can then put them out in appropriate spots.  Gophers will eat a lot of plants, but putting your plants in rocky areas can reduce the likelihood of them being eaten by gophers.  The problem with gophers is that they eat the plants from below without your knowledge.  Sandy soils can be used, making it difficult for burrowing gophers to make tunnels.

 

Fencing around plants can be used to reduce feeding until the plants become adapted to the planting site.  Gradually reduce the watering to the plants to encourage them to become adapted to your yard.  Over-watered plants are far more attractive to herbivores such as deer and rabbits.

 

Food plants should be planted in such a way to be in high enough quantity to support larval development, but should also be scattered to some degree if you have enough area in your yard to support more than one patch of a food plant.  Patches of annuals for some butterflies such as the Quino Checkerspot will be needed for grazing post-diapause larvae.  Planting patches separate from one another can help butterflies if a virus or parasitoid becomes established at one of the patches.   Sometimes it is also best to plant your food plants some distance from the nectar sources.  These nectar sources will be attractive to parasitoids as well as to butterflies.  Parasitoids and viruses will kill butterfly larvae.

At Right: An adult desert checkerspot butterfly nectaring on a flower.