Variegated Fritillaries are easy to raise and release. Often, a pair of butterflies will mate in the cage, so you will have lots of frits in your garden once you get started.
If you want to raise Variegated Fritillaries, leave violets in your yard and move some into a patch. Get a passion vine or two. I have a large area of wild violets (about 8’ x 10’) right in front of my house. That is also where the passion vine pops up. There is another patch of violets beside my house (about 8’ x 8’) scattered in with ferns and astilbes.
Once you get the host plants, you need to find the caterpillars. The babies look like a miniature of the adult caterpillar. They are reddish brown with dorsal and lateral stripes of alternating black and white patches. They have six rows of black spines. They’re very pretty. I don’t try to harvest the eggs, just the tiny babies on up.
The best time of day to find the caterpillars is in the morning after the sun has warmed things up and critters are moving. I will look all during the day and early evening. (I guess it’s called “no life.”)
You then place the caterpillars in a cage with screening to let fresh air in, but keep predators out. You can find plans for some simple cages at www.butterflysocietyofva.org. I use three large cages built by late Butterfly Society member Don Denault out of cedar with double screening. They are double decker cages with hinged doors and solid wood roofs. They are in a separate screened-in room outside— my husband got tired of all the caterpillar “stuff” on the porch and built a room for them. He put in a raised L-shaped counter and I put linoleum tiles down and the cages on them. I have a baker’s rack for water, extra food containers, etc. The room has lights and a ceiling fan.
The caterpillars are fed passion vine and violets. Inside the cages I use small vases for violet leaves and passion vine branches. When I had a lot of caterpillars to feed, I used bowls and placed a whole violet plant in it (with water, of course). After that was eaten, I could replant and pull up another. I used bamboo poles and a terra cotta finial to build a type of trellis to run the passion vine on. Frits like to lay their eggs close to the ground but this gave me longer branches to cut for cage feeding. I occasionally did find a few cats that had ventured up to eat.
When the cages got yucky—about every other day when there were a lot feeding, I would move the caterpillars into another cage and pull out all of the food containers and paper toweling (used to cover the bottom on the cage). I used a soft-bristled makeup brush to “sweep” out all of the frass and any other trash. Next I would re-line the bottom, replace the food in clean water and move ‘em back in. On other days, I used the brush and small dustpan to sweep out the frass by just moving the containers around. Cleaning and feeding takes a lot of time. With the three large cages I probably would spend a couple of hours to clean them out.
The best time of year to find Variegated Fritillary caterpillars in your yard is in summer (June) after the days really begin to warm up. Most will be found in the hot months—July, August, and September.
I began gathering in June 2007 and the first release I have is July 12 (1 Var. Frit. butterfly released)
July 12: 1
July 13: 2
July 14: 0
July 15: 5
July 16: 6
July 17: 6
July 18: 5
July 19: 9
By August 5th I was releasing 10 or more a day:
August 5: 19
August 6: 23
August 7: 21
August 8: 25
August 9: 28
August 10: 18
My highest numbers were Aug. 23 (32 Frits) and Aug. 24 (31 Frits). The last release date noted on my calendar was Sept. 22 (3 Frits).