Phenology: Monarch Butterfly, Gardening, Farming

(This was written on November 13, originally scheduled for November 15; it’s been separated into two posts due to length, and will have to appear on November 16 and 17, due to drama at the Cat Sanctuary on November 14 and 15.)

Not last night, but the night before, rain washed most of the leaves off most of the trees. The predominant color of the hills is now drab, with a few lingering patches of oak, beech, pine, or cedar. Nevertheless, we’ve had only one or two brief dips below the freezing mark, and insects remain active. One of the spring kittens managed to pick up a dog tick last week.

And yesterday I saw a monarch butterfly, Danaus plexippus. This is one of the best known and best loved butterflies on Earth…

(Credit: “Monarch In May” by Kenneth Dwain Harrelson. Licensed under CC BY-SA 3.0 via Commons – )

They’re popular because they tour. The one I saw was heading south for the winter, and may come back in the early spring, when milkweed begins to sprout. The female Monarch is restless in spring, and lays only one or two eggs on each milkweed plant. On a quiet day you can hear her wings flap as she flits from plant to plant. Monarch caterpillars eat nothing but milkweed; more than one or two of them might kill their host plant. When they reach their full size, which can be a little over two inches long, the caterpillars often look for a plant other than milkweed on which to hide while they rest and turn into butterflies.

They spend ten or fifteen days pupating, during which they don’t spin cocoons and are visible but don’t look like living animals, and then emerge–as adolescents. Monarch butterflies reach full maturity only when they’re ready to reproduce. In summer this takes four or five days; for the alternate generation, who hatch in winter, it takes the whole winter season.

For hundreds if not thousands of years, monarch butterfly populations were stable. The species became threatened only recently. Efforts have been made to rebuild population levels…

However, the species has been severely threatened by humans’ abuse of chemicals. Monarch butterflies are harmless to plants humans can eat, but they’re vulnerable to poison spray.

Despite the science fiction in the novel Flight Behavior, monarchs are not seriously believed to be endangered by global warming…although, if some of the global warming scenarios scientists have projected were to come true, they would be. The butterflies are most seriously endangered by herbicides that are sprayed, or drift on the wind, onto their host plant milkweed. They are also vulnerable to insecticides, although they tend to scatter themselves widely enough that population levels were not threatened by insecticides alone.

Are the “organic pesticides” discussed below really more toxic than glyphosate or DDT or whatever? Depends on the concentration in which they’re used; water could be “more toxic than DDT” if we’re talking about a trace of DDT on the peel of a peeled apple versus enough water to drown in. Thing is, if you really get into sustainable organic farming or gardening, the “organic pesticides” are going to be like that rifle I didn’t actually buy, last summer, for the purpose of killing a nuisance animal–you don’t even think about them every year. I’ve recommended the oil-and-vinegar treatment for poison ivy, but do I myself use it? No; I dig up my own poison ivy by the roots, which is a better option I’ve recommended for long-term poison ivy control. Another good option is owning (or renting) a goat; they can become lovable pets, and they eat poison ivy.

(More about sustainable farming and gardening forthcoming…)