Butterflies on the brink

I am sure that back in Sullivan’s Island Elementary School or the now-defunct East Cooper School in Mount Pleasant, I heard the scientific name for butterflies and moths, Lepidoptera.

 

But, as one beloved teacher, Mrs. Rebecca Tuten, frequently pointed out, “You boys are simple and silly.”

 

I might have missed how important butterflies are while shooting staples at friends with my pencil when my science teacher wasn’t looking.

 

Forty-three years later, I wish I had paid more attention. These insects are critical to how our natural world functions, and many of them are in real trouble today.

 

Monarch Population Grim

There are over 17,000 kinds of butterflies, and it is difficult to speak generally about them. 

 

Please accept that some are doing better and some are doing worse than the average butterfly.

 

Much like bees, their role in pollination alone makes them critical to our natural world. Bees are highly efficient pollinators, but butterflies pollinate a wider range of plants.

 

One need look no further than our most recognizable butterfly, the monarch, Danaus plexippus, to see the gravity of their plight.

 

The migrations of monarchs are well-known. Millions of these beautiful creatures move annually between the western U.S. and Canada to coastal California (western monarchs) or from eastern Canada and the U.S. to, primarily, the mountains of central Mexico (eastern monarchs). Some remain in Florida year-round. There seems to be little biological difference between the two monarch populations, just a geographical one.

 

Rather than by counting individuals, as in bird counts, butterfly counts in Mexico are done by counting the number of hectares occupied on their wintering grounds. This number is then multiplied by an assumed number of specimens per hectare. A hectare is roughly 2.5 acres and, according to Monarch Joint Venture, the factor assumed is between 20 and 30 million butterflies per hectare. While not an exact science, this method provides the best estimate we currently have for total population.

 

The trend in that population is grim, and last December the U.S. Fish and Wildlife Service proposed listing monarchs as threatened under the Endangered Species Act.

 

Over the last 30 years, the eastern monarch population estimate has fallen from 6.23 hectares to 1.8. Habitat and food loss, climate change, and pesticides are cited as the most likely causes. For some unknown reason, wintering numbers doubled last year from 0.9 hectares up to 1.8. There is always hope!

 

How To Help

The monarch alone would take more than a newspaper column to discuss, but there are many informative online resources.

 

If one wants to help our monarchs, please see The World Wildlife Fund or Monarch Joint Venture. Insectsofiowa.org also has a great photo-based butterfly identification tool for any North American variety.

 

The single biggest help to the monarch is probably to plant milkweed. According to a 2023 article in Coastal Georgia Botanical Gardens, milkweed is the only plant on which monarchs can lay their eggs and on which their caterpillars can feed. Imagine that – a species entirely reliant on a single plant.

 

Unfortunately for the monarchs, milkweed is not particularly attractive, is not sought after for landscaping, etc., and is frequently mowed and sprayed along roadways, in fields, and in other places where it grows well. 

 

Reducing that practice and minimizing pesticide usage could have huge benefits for the monarchs, and they need all of the help they can get.