As we prepare for an abundant season of food for our CSA members and market, we are also planning food sources for the pollinators which perform a valuable service on the farm. While bees are often the first pollinator which comes to mind, there are a variety of pollinators we depend on. One of the most lovely is the Monarch. The adults may feed on the nectar of many plants, but the species depends primarily on a single genus of plants, commonly known as milkweed for egg-laying and as a food source for the young larvae. The insectary, is a portion of the garden dedicated to plants and flowers which invite pollinators and other beneficial insects to the garden.
The declining population of this pollinator has greatly concerned scientists lately. There is a worry that they could become extinct in a very short time unless something changes. Many people love the Monarch, and, unlike some insects; it is an easy creature to admire. It is beautiful; it has a unique migratory habit, and great cultural significance. In Mexico, they symbolize the souls of those who have passed on, and the migratory return in November coincides with the holiday, the day of the dead. Across North America the Monarch is a symbol of summer, where butterflies frolicking in the sun rank right up there with cold watermelon and a day at the lake.
Pathogens and parasites have an influence on natural populations of Monarch. For this reason, many people are raising the young caterpillars from the egg stage to maturity in a protected environment in order to increase the reproductive success of the Monarch. When combined with these natural pressures, human influence, which leads to vast landscape changes and the introduction of toxins into the environment, increases the difficulty for the population to remain stable. Modern agricultural methods are directly related to the plight of the Monarch.
Modern agricultural trends which affect the Monarch include: farm consolidation, increasing herbicide use, and pesticide use. The consolidation of small farms into large industrial food complexes reduces the amount of traditional field border which often contained the food plant of the Monarch, Milkweed. Herbicide use has increased, due to modified crops which will tolerate glyphosate and its application to ever larger areas on consolidated farms has eliminated healthy Monarch habitat in these areas. Pesticides are not aimed at any particular species, but an entire trophic level. There is no way to distinguish among the good insects and the bad ones. The use of these chemicals in agriculture, horticulture, and increasing availability to homeowners who may not fully understand the consequences of their widespread application greatly reduces the number of safe places in the landscape for the migratory Monarch.
“Milkweed”, the food plant of the Monarch caterpillar, includes more than 100 species of the genus Asclepias and suffers from a negative label. When classified as a “weed” or “pest” elimination becomes the natural goal. In the past we have battled with pests and considered them such an invincible foe that we did not imagine that they could be reduced to a level of concern. We are so invested in the battle which seems justified by a negative label that we fail to see the essential role that they fill and how it may connect to us. But history has shown us to be quite successful in eliminating pests. The Passenger Pigeon and Carolina Parakeet, both now extinct were both considered agricultural pests in the United States.
One advantage of Organic agriculture is that it treats the farm as an agricultural ecosystem where problems are ideally managed through rotation, timing, and increased diversity rather than chemicals. This is good news for wildlife, and us as well. Unfortunately, most insects do not capture our hearts and imaginations the way that the Monarch does, yet we are only a few steps away from them on the food chain.
Biologists know that in any ecosystem, problems in one portion of the food web, often lead to trouble in other portions of the system, including the human societies which are a part of them. For this reason indicator species are often selected which serve as a measure of the health of the ecosystem, and they also serve as an early warning system if something is wrong in the system, like a canary in a coal mine. Some indicators are chosen because they are susceptible to some environmental factor, such as water quality or toxins, and others are chosen because of economic or cultural significance. If the Monarch is viewed as our canary, it’s not doing so well.
Glyphosate, which has virtually eliminated milkweed from farm ecosystems, has also been linked to several human illnesses. Residue remains on foods and has even infiltrated the public water supply at low levels through agricultural run off in some areas. Despite growing health concerns and questions of safety with this chemical, permissible levels are increasing rather than decreasing.
If you’d like to learn more about Monarchs and how to help their populations, the Monarch Larva Monitoring Project (mlmp.org) is one place to go for information and to participate in this citizen science project. Even if you do not wish to become involved in research, to increase your enjoyment of the Monarch, you can make certain to avoid harmful chemicals on flowers which may be useful to pollinators and be sure to plant some milkweed to help this migrant complete its annual cycle.
Here’s a link to a recent article about health concerns with glyphosate exposure.
My thanks to Brenda Keith for providing photos of the wonderful work she does each year, helping to boost populations by raising larvae to maturity.