A monarch butterfly fluttered past The Islander’s office window to settle on a hibiscus petal.
Monarchs can be found year-round on Anna Maria Island, yet when I see the butterfly, I still think of spring and summer, because that’s when I saw them as a child in Illinois.
Sadly, I see fewer monarchs than I did a decade ago, and I’m not alone in this observation.
Research from the Florida Museum of Natural History, the University of Florida and Hamilton College in New York shows Florida’s monarch butterfly populations dropped 80 percent since 2005.
The researchers based their study on a 37-year survey of monarch populations — caterpillars and butterflies — in north central Florida. The scientists examined milkweed plants for caterpillars and captured adult butterflies for 37 years — a period spanning more than 140 generations of monarchs.
Study co-author Jaret Daniels at the museum’s McGuire Center for Lepidoptera summarized the research results: “This study shows the tight connection between monarchs and milkweed and highlights very dramatic losses in abundance in Florida that further confirm the monarch is declining.”
While Florida hosts monarchs year-round, Florida also hosts migratory monarchs. Their springtime departure from Mexico to Florida and elsewhere in the southeastern United States is timed to coincide with growth of milkweed, where the monarchs will lay hundreds of eggs.
Monarch larvae feed almost exclusively on milkweed — not the tropical milkweed (asclepias curassavica) found in the garden departments of big box stores but the native milkweed we should find in our yards and alongside roads.
To maximize their offspring’s chances of survival, the butterflies must time their United States arrival within a three-week window, according to Daniels, who described Florida as a staging ground for the monarch’s recolonization of the East Coast.
If the species suffers in Florida, it suffers elsewhere.
The researchers pointed to the shrinking populations of native milkweed as a factor in the monarch’s decline.
They also pointed to the application of glyphosate, a herbicide used to eliminate weeds, as a factor in the monarch’s decline. Glyphosate, the active ingredient in Monsanto’s Roundup, wipes out milkweed.
The Florida decrease parallels falling numbers in the monarch’s overwintering grounds in Mexico.
The plight of this pollinator has led some environmental groups to call for protections under the federal Endangered Species Act.
Others have pressed for a grass-roots response, with a campaign to protect and grow butterfly habitat, particularly by planting herbicide-free milkweed plants needed for the species to continue.
About 20 types of milkweed plants are native to the state, according to the University of South Florida’s plant atlas.
Some species include:
• Swamp milkweed, asclepias incarnate, which grows best in wet areas in central Florida and southward.
• Aquatic milkweed, asclepias perennis, found in wet areas in central Florida and northward.
• Fewflower milkweed, asclepias lanceolata, found in wet areas throughout the state.
• Butterflyweed, asclepias tuberosa, found throughout the state in dry to semi-dry areas.
Remember, if there is no milkweed, there are no monarchs.
This column was published in The Islander newspaper.
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