Q: For several weeks in fall, beautiful orange butterflies visited my garden. From online pictures, I identified these visitors as Gulf fritillary butterflies. I have not seen them in previous years. I would like to know what I can do to encourage them to remain.
Terri Friedman, Carmichael
According to UC master gardener Rachel Tooker, the best way to encourage the Gulf fritillary butterfly (Agraulis vanillae) is to plant passionflower vine (Passiflora), which is the butterfly’s larval host.
Adult butterflies lay eggs on the vine’s tendrils and top and bottom of its leaves. The eggs become spiny, orange and black caterpillars that feed on the leaves and then form into the chrysalis that hatches into the adult butterfly. Understanding the butterfly’s life cycle and avoiding the use of pesticides while caterpillars are feeding can help you to protect these beautiful insects.
In addition to the passionflower vine, adult butterflies also are attracted to lantana and Mexican sunflower, among other plants. Beautiful photos of the adult Gulf fritillary butterfly and its caterpillar can be found on Kathy Keatly Garvey’s website, the Bug Squad: http://ucanr.edu/blogs/bugsquad/index.cfm.
According to UC Davis butterfly expert Art Shapiro, distinguished professor of evolution and ecology, the Gulf frittilary has been making a comeback in the Sacramento area since 2009:
“This dazzling bit of the New World tropics was introduced into Southern California in the 19th century – we don’t know how – and was first recorded in the Bay Area before 1908, though it seems to have become established there only in the 1950s. It can be quite common in the East and South Bay – particularly in Berkeley – and has been found breeding spontaneously as far inland as Fairfield, where, however, it is not established.
“There are scattered records in the Central Valley and even up to Folsom, perhaps resulting from people breeding the species for amusement or to release at social occasions,” Shapiro added. “This butterfly has no native host plant in California and is entirely dependent on introduced species of the tropical genus Passiflora (passionflower, passion vine), including the common Maypop (P. incarnata) and P. X alatocaerulea. However, it will not eat all of the Passiflora in cultivation in California.”
For more, see Shapiro’s website: http://butterfly.ucdavis.edu/butterfly/Agraulis/vanillae).
If you have an interest in understanding more about butterflies in the Sacramento region, you may want to check out “Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions,” by Shapiro and Tim Manolis, published by University of California Press.
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