Editor's note: Rotating authors affiliated with Santa Monica's Community Gardens will be contributing a regular feature to the paper. The column will run twice a month and touch on a variety of topics associated with the community gardens.
By Talia Tinari
She's beautiful. Orange, black and white wings beating as she lands on the milkweed and lays her egg. A monarch butterfly. She's off in a minute to mate again, find another milkweed, lay another egg. This egg will hatch in three or four days, provided nothing knocks it from the leaf, but it's February in Santa Monica, and dry and not too windy. She's found a haven in the Santa Monica Community Garden.
When the egg hatches, the caterpillar will be a tiny 2 millimeters long. She'll eat the milkweed on which she hatched. It will provide all of the nutrients she needs, as well as the sap containing cardiac glycoside toxins making the larva and adult butterfly poisonous to predators.
In two weeks she'll be 45 millimeters long, having molted five times, now all fat black, white and yellow stripes. She'll form her chrysalis and emerge as the regal winged insect and fly west to mate, lay her eggs, and create another generation.
There are two groups of monarch that migrate through North America, the Western monarchs and the Eastern monarchs know as the subspecies Danaus plexippus plexippus. The group from the Eastern United States overwinters in Mexico and those West of the Rockies overwinter in coastal California. Our monarchs, the Western monarch, winter from around September to March, then spread across the western United States and into Mexico and produce several generations until they migrate back to California for the winter.
In 1997 there were more than 1.2 million monarchs overwintering in California and in 2014 only 234,000 - an 81 percent decline from the 1997 high, 48 percent decline from the 18- year average, and just over 10 percent per year. What has caused such a decline?
The Xerces Society for Invertebrate Conservation, which studies and tracks the monarch populations has several theories; the loss of milkweed breeding habitat, herbicides and pesticides, GMO herbicide resistant crops, development and logging at their over wintering sites, climate change, and extreme weather, such as the multi-year drought California has been experiencing.
The herbicide glyphosate, know commonly as Monsanto's Round Up, used in both commercial agriculture and in backyard gardening, has lead to the decline of milkweed plants. Neonicotinoids (a class of neuro-active insecticides chemically similar to nicotine), which began to be widely used commercially in the 1990's, are also a factor in the decline of the butterflies. Neonicotinoids have been found in soil and can be taken up into the plant, and are lethal to monarchs.
In 1969 mathematician and meteorologist Edward Lorentz coined the term butterfly effect. In Chaos Theory it's defined as the sensitive dependence by which a small change in one state can result in large differences in a later state. Lorentz used the example of the fluttering wings of a butterfly in one place having major effects on weather on the other side of the planet.
Here, it would seem that small changes to the butterfly's habitat, means less butterflies and less beating of wings. What happens to the planet when a population of any organism is reduced by almost half? This isn't a question our generation can answer, nor one we should expect the next generations to solve.
It is essential to stop using insecticides and herbicides in the backyard garden. We can also help to bring back the monarchs by planting milkweed. In Santa Monica and throughout California you can plant showy milkweed (Asclepias speciosa) and narrow-leaved milkweed (Asclepias fasciularis). Both are native species and encourage overwintering. The cardiac glycoside toxins in the plants can be poisonous to vertebrates, and should not be planted if you have pets or young children who might ingest it.
The Santa Monica Community Gardens have increased their milkweed plantings and have registered as a Monarch Way Station with Monarch Watch, an organization that helps create and track overwintering sites. You can do the same at monarchwatch.org. Milkweed seeds are also available through Monarch Watch and The Theodore Payne Foundation (theodorepayne.org). The Main Street Community Garden will be open for the Coast Open Streets on June 5 with free milkweed plants, seeds and activities. We hope to see you there!
Talia Tinari writes on behalf of the Santa Monica Community Gardeners. Want to learn more about the Santa Monica Community Gardens? Contact us at santamonicaroots@gmail.com. Follow Santa Monica Roots on Facebook, Twitter, and Instagram.
