J. McKinney
DRAFT Bio 28: The Mission Blue Butterfly
Fall 2010/Page 1
The Mission Blue Butterfly
(Icaricia icariodes missionensis)
Mission Blue butterfly
Conservation status
Critically Imperiled (NatureServe)
There are currently 144 butterfly species living in
the San Francisco Bay Area. Two butterfly species that
used to live in the dunes are now extinct, and several
butterfly species now have special status as threatened
or endangered species.* Among them are the
commonly named San Bruno Elfin Butterfly
(Callophrys mossii, Incisalia mosii bayensis), the Bay
Checkerspot Butterfly (Euphydryas editha bayensis), the
Behren’s Silverspot Butterfly (Speyeria zerene
behrensii), the Callippe Silverspot Butterfly (Speyeria
callippe callippe), the Myrtle’s Silverspot Butterfly
(Speyeria zerene myrtleae), and the Mission Blue
Butterfly (Icaricia icariodes missionensis).
Formerly relatively widespread throughout the San
Francisco and Marin peninsulas, the Mission Blue
Butterfly now remains at only a few sites in the coastal
counties, primarily on San Bruno Mountain in San
Mateo County, but also the Twin Peaks and McLaren
Park areas of San Francisco, as well as the Marin
Headlands and Fort Baker in Marin County. San Bruno
Mountain hosts the largest population of Mission blue
Butterflies.
The Mission Blue Butterfly has a wingspan ranging from 2.5 to 3.6 cm (1-1½ in).
The male has silver blue to violet blue upper wings with a dark border and fringes made of
long white hair-like scales. The female has dull brown upper wings, with only small traces of
blue. The underside of the wings of both the male and female appear silver gray or brownish,
with small gray and larger black circles.
The Mission Blue Butterfly requires the type of coastal
scrub and grassland habitat found only near the Golden Gate
of San Francisco, and three species of lupine provide food
and shelter for the butterfly in its larval stage. The adult
Mission Blue Butterfly drinks the nectar of a variety of
flowers, many in the sunflower family. They require the
lupine to lay their eggs on and nourish their larvae. Without
the lupine the Mission Blue Butterfly cannot reproduce.
Mission Blue Butterfly–female
©Bob Kipka, March 2008
flickr.com/photos/bobkip/2372280865/
*
*Note: Under the Endangered Species Act in the United States, "threatened" is defined as "any
species which is likely to become an “endangered” species within the foreseeable future throughout
all or a significant portion of its range". It is the less protected of the two protected categories. At
San Francisco Bay Area Wildlife (sfbaywildlife.info) they use the term "endangered" in a more
general sense to include all rare, threatened or vulnerable species.
J. McKinney
DRAFT Bio 28: The Mission Blue Butterfly
Fall 2010/Page 2
The life cycle of a Mission Blue
Butterfly lasts only one year. The adult
butterfly only lives approximately one week.
The butterfly lays its eggs on the leaves, buds
and seed pods of one of three types of lupine,
the Lindley varied lupine (Lupinus variicolor),
the Silver lupine (Lupinus albifrons), or the
Summer lupine (Lupinus formosus). The eggs
generally hatch within six to ten days. In the
Lindley varied lupine (Lupinus variicolor)
http://www.baynatives.com/plants/Lupinusfirst two larval stages they feed on the interior
variicolor/17_DSC0037.jpg
of the leaves of the lupine plants. The
caterpillars are extremely small and after feeding for a short time, they crawl to the base of
the plant where they enter a dormant state until late winter or the following spring. They
enter the dormant state about three weeks after hatching from their eggs, which is about the
same time as the host lupine plant shifts its energy to flower and seed production. When the
caterpillar comes out of its dormant state and begins feeding, it may shed its skin to
accommodate its growth.
Silver lupine (Lupinus albifrons)
http://www.wildflower.org/image_archive/320x240/PCD3
541/PCD3541_IMG0003.JPG
As the larvae feed and grow, native ants
will sometimes gather and often stand on the
caterpillar and tap it with their antennae. In
response, the caterpillar secretes a sweet
honeydew and the ants drink the liquid. In
return a relationship develops in which the
ants ward off predators and parasites. Mission
Blue Butterfly eggs have been found with
parasitic wasps and flies although rodents are
probably the principle predator of larvae and
pupae.
Once the caterpillar is fully grown, it forms a chrysalis after securing itself to a surface
which is generally a lupine stem or leaf and sheds its outer skin, revealing the chrysalis. This
stage lasts about ten days while the adult butterfly develops. The butterflies can be sighted as
early as late March in places like San Bruno Mountain or Twin Peaks. They may be seen
well into June perched on a lupine plant or feeding on coastal buckwheat flowers. The adult
Mission Blue Butterfly lives approximately one week and spends most of its time flying,
foraging for nectar, perched or mating. After
mating, the females begin laying eggs on the
host lupine plant and the one year life cycle is
completed.
Summer lupine (Lupinus formosus)
© 2006 Doreen L. Smith
http://calphotos.berkeley.edu/imgs/128x192/0000_0000/0
908/0498.jpeg
Mission Blue larvae and caterpillars will
feed only on the leaves of the three host
lupines: Lindley varied lupine (Lupinus
variicolor), Silver lupine (Lupinus albifrons),
and Summer lupine (Lupinus formosus).
Adults may drink the nectar of composite
flowers (sunflower family), golden asters,
buckwheat, wild hyacinths and other plants
using a long tube called a proboscis that
extends from the underside of the head.
J. McKinney
DRAFT Bio 28: The Mission Blue Butterfly
Fall 2010/Page 3
The San Bruno Mountain population is
estimated at 18,000 adults. The Skyline
Ridges support approximately 2,000 adults,
and there may be as many as 500 at Twin
Peaks. The Marin Headlands population
has not been estimated, but is significant.
To locate a mate, adults patrol around in
patches of host plant, rarely straying far
from the lupine habitat. On rainy, cool,
windy, or foggy days, adults hide out
underneath vegetation.
The main threat to the Mission Blue
Butterfly is habitat loss due to agricultural
and urban expansion while various parasites
and predators threaten the Mission blue
during its life cycle. Eggs and larvae are
parasitized by other insects, such as wasps
and flies, and rodents prey upon both larvae
and pupae. The invasion of exotic plant
species, such as ice plant, pampas grass,
French broom, gorse, and eucalyptus, also
http://bss.sfsu.edu/holzman/courses/Fall00Projects/MissionBlue.htm
threatens habitat. Trampling of host plants,
larvae, and pupae by humans and dogs is
also a problem in some areas. The Mission
Blue Butterfly was added to the Federal Endangered Species List in 1976, and is protected
under the Endangered Species Act.
The Marin Headlands
http://en.wikipedia.org/wiki/Mission_blue_b
utterfly_habitat_conservation
Fog over San Bruno Mountain
http://en.wikipedia.org/wiki/Mission_blue
_butterfly_habitat_conservation
During the time that the U.S. military occupied the
Marin Headlands, many trees were planted. Some of the nonnative species have now become native to the area and
threaten the habitat of the endangered Mission Blue Butterfly
including the Blue Gum Eucalyptus, Monterey cypress,
Monterey pine and black wood acacia. The Mission Blue
Butterfly User Fee Project in the headlands will try to remove
these species and re-vegetate the area with native coastal
prairie plants.
Another major conservation effort is underway at San
Bruno Mountain. A large area of Mission blue habitat has
been protected under the auspices of the U.S. Fish and
Wildlife Service (USFWS). In all, the San Bruno Mountain
habitat conservation program has protected over 3,500 acres
(14 km2) of habitat since 1983. San Bruno Mountain was the
site of the nation's first Habitat Conservation Plan (HCP),
intended to protect the habitat of the mission blue. However,
HCPs remain controversial. In exchange for permission to
build near the prime habitat of two California endangered
butterflies, the Mission Blue and the San Bruno Elfin
Butterfly, landowners agreed to measures to improve the
prospects for the species' survival in other locations.
J. McKinney
DRAFT Bio 28: The Mission Blue Butterfly
Fall 2010/Page 4
Developers have agreed to work with others to stop exotic plant invasions on butterfly habitat
and began to undertake the daunting task of replacing the invasive species with lupine for the
butterflies to relocate to. The project started in 1985, but gorse, a hardy plant related to
French broom, can reach heights of 20 feet (6.1 m) with deep root systems.
Abandoned building at Fort Baker
http://en.wikipedia.org/wiki/Mission_blue
_butterfly_habitat_conservation
Fort Baker is an abandoned base formerly occupied by
the U.S. Army. It is near the city of Sausalito, California. As
part of the mission to protect Mission Blue Butterfly habitat
the project will seek to physically remove and/or contain
those species in areas within or adjacent to the "host plant"
Silver lupine (Lupinus albifrons). Upon completion, the area
will be completely invasive-tree free. A legal battle also
ensued when the National Park Service announced plans to
finally allow a development group to build a large, longawaited hotel/conference center complex on the remains of
Fort Baker. It resulted in the project being trimmed down to
a 144-room hotel complex although the legal settlement
actually capped the room capacity at a higher 225.
Twin Peaks is also home to a reported population of
Mission Blue Butterflies. The entire area is a park managed
by the San Francisco Recreation & Park Department and
contains 31 acres (130,000 m2) of what the Park Department
terms "Natural Areas." They include some of the largest
areas of coastal scrub and prairie that remains within the city
of San Francisco. Amongst the coastal scrub and prairies are
Silver lupine plants (Lupinus albifrons) which can support
San Francisco from Twin Peaks
http://en.wikipedia.org/wiki/Mission_blu colonies of endangered mission blues. In April 2009, a
e_butterfly_habitat_conservation
reintroduction was attempted with the release of 22 butterflies
from the San Bruno Mountain population.
It is thought that lupines require periodic fires, landslides, or other disasters in order to
successfully reproduce. In the area where the 2004 “Solstice Fire” occurred, Monterey pines,
an invasive species that has become "naturalized," is continually encroaching on the coastal
grasslands that the Mission Blue Butterfly prefers and requires. Over 250 trees were
removed from the area after the fire. The area was seeded with native plants, among them
400 Summer lupine (Lupinus formosus) seedlings. In 2004 the "Lateral Fire" burned within
Fort Baker, a half mile south of Sausalito, and threatened the habitat of the Mission Blue
Butterfly. The fire happened within a 17-acre (69,000 m2)
habitat restoration project and burned areas of the butterfly's
host lupine plant, Silver lupine (Lupinus albifrons). The fire
burned about 300 plants. Control of non-native species
trying to reinvade the area was cited as a key measure in
protecting the lupines. Non-native French broom and Italian
thistle were among the invasive species seeking to re-enter
coastal grass and scrubland. Interestingly enough, living
Mission Blue caterpillars were found on a number of burned
lupine plants. According to the life cycle of the Mission Blue
Invasive French broom moved
into the Lateral fire burn area
Butterfly, these eggs would have had to have been laid before
http://en.wikipedia.org/wiki/Mission_b
the fire. This would indicate that the butterflies, albeit in the
lue_butterfly_habitat_conservation
early larval stages, survived the fire.
J. McKinney
DRAFT Bio 28: The Mission Blue Butterfly
Fall 2010/Page 5
The National Park Service, in partnership with
the Parks Conservancy, carried out prescribed burns
in the Marin Headlands west of Highway 1 and at
Milagra Ridge near Pacifica between August and
September 2010. In the Headlands, burns were
applied to an infestation of invasive, non-native
grasses, and small “burn boxes” were used at both
sites to restore endangered Mission Blue Butterfly
habitat. These prescribed burns were conducted by
the highly trained professionals of the Golden Gate
National Recreation Area's Fire Management
Program.
Some herbaceous species have characteristics
that require heat for seed germination, and they have
nitrogen-fixing bacteria in their roots. Among these
are members of the pea family (Fabaceae), including
Prescribed burn helps native plants
http://www.parksconservancy.org/our-work/sitea variety of lupines (Lupinus spp.). Apparently
stewardship-program/about/prescribed-burns.html
chaparral fires cause a tremendous loss of nitrogen
from the ecosystem by the burning of nitrogenous compounds such as proteins in plant
tissues and detritus. It has been determined that a direct loss of 133 to 178 pounds of
nitrogen per acre (150-200 kg/ha) could result from a moderate fire. During the first years
after a fire, species equipped with nitrogen fixing bacteria dominate because they grow
quickly on the disturbed terrain, and they resource nitrogen to the system. For the first few
years after a fire, Lower Chaparral is dominated by short-lived herbaceous plants, including
many brightly colored wildflowers. Among these are the lupines and several members of the
waterleaf family. (Schoenherr, pp. 346-347)
Milagra
Ridge
Prescribed
Burn Areas
http://www.parksconservancy.org/assets/ssp-assets/ssp-pdfs-docs/milagra-ridge-map-burn.pdf
J. McKinney
DRAFT Bio 28: The Mission Blue Butterfly
Fall 2010/Page 6
How can people help?
People can contact local
conservation organizations for
more information and sign up to:
The Mission Blue Project
http://www.missionblueproject.com/images/Mission%20Blu
e%20male%20opening%20his%20wings.jpg
 Plant a butterfly-friendly garden. By creating
patches of butterfly-friendly habitat, people can
combat the main threats facing butterfly
populations. People can learn to incorporate
butterfly-friendly practices into their gardening
and land management.
 Get involved in habitat restoration projects in
critical butterfly habitat. People who give this
work a try often get hooked. These
organizations often have regular work dates and
will provide water, snacks, sun and wind
protection, and gloves and tools.
 Join in monitoring the presence of endangered
butterflies, identifying their location, counting
their numbers, and reporting the data and
important species information.
The Butterfly Conservation Initiative
http://www.butterflyrecovery.org/species_profiles/mission_blue/
Center for Biological Diversity/Bay Area Butterflies
http://www.biologicaldiversity.org/swcbd/SPECIES/bayareabutterflies/index.html
Golden Gate National Parks Conservancy
http://www.parksconservancy.org/our-work/site-stewardship-program/
San Bruno Mountain Watch
http://www.mountainwatch.org/mountain/fauna/missionbluebutterfly.htm
Wild Equity Institute
http://wildequity.org/species/26
J. McKinney
DRAFT Bio 28: The Mission Blue Butterfly
Fall 2010/Page 7
Bibliography
Print Sources
Schoenherr, Allan A. A Natural History of California. Berkeley, California:
University of California Press, 1992.
__________. Atlas of the Biodiversity of California. Sacramento, California:
California Department of Fish and Game, 2003.
Online Sources
The Butterfly Conservation Initiative
http://www.butterflyrecovery.org/species_profiles/mission_blue/
Center for Biological Diversity/Bay Area Butterflies
http://www.biologicaldiversity.org/swcbd/SPECIES/bayareabutterflies/index.html
http://www.biologicaldiversity.org
Golden Gate National Parks Conservancy
http://www.parksconservancy.org/our-work/site-stewardship-program/
Melton, Joseph. “The Biogeography of the Mission Blue Butterfly,” San
Francisco State University Department of Geography, 2000.
http://bss.sfsu.edu/holzman/courses/Fall00Projects/MissionBlue.htm
San Bruno Mountain Watch
http://www.mountainwatch.org/mountain/fauna/missionbluebutterfly.htm
San Francisco Bay Wildlife Information/sfbaywildlife.info
http://www.sfbaywildlife.info/species/endangered.htm
Wikipedia
http://en.wikipedia.org/wiki/Mission_blue_butterfly_habitat_conservation
Wild Equity Institute
http://wildequity.org/species/26