This male was photographed 6-8-2005 at Sawmill Campground in the Angeles National Forest.
A nice hi-res image of a female specimen, taken at Sawmill Campground, June, 2005.
Images of living insects, northern Los Angeles county, June, 2004
Older, low-res images
A number of people have mentioned difficulties in distinguishing male and female fritillaries. Females are usually larger and a bit lighter colored than the males, plus females usually begin flying 1-2 weeks after the males first emerge. Even so, the wing patterns are somewhat variable in both sexes, making it difficult to tell.
The most reliable method is to examine the genitalia at the end of the abdomen. The images below were shot 6-24-2005 and 6-25-2005 show a number of views for reference. Row 1, two left images show the male on the left while the two right images show the male on the right. The
entire specimen is shown so that differences (or lack thereof) in wing shape, pattern, and coloration can be seen. Row 2 show close-ups of a male. Note the claspers are visible. Row 3 are closeups of a female which show the semi-protruding ovipositor.