Troops of Monarch Caterpillars Eat Letchworth’s New Butterfly Garden for Fall Migration

CASTILE – Monarch caterpillars have been making exceptional appearances outside Letchworth State Park’s Humphrey Nature Center in these last few weeks of summer.

Monarch butterfly larvae, or caterpillars, are munching the milkweed planted especially for them in the Nature Center’s butterfly garden. The $6.75 million, 5,000 square foot Nature Center just opened to the public this past June.

“Yay, we saw monarchs flying around there last month,” posted Laurie Beth Matteson Cunningham on Letchworth State Park’s Facebook page. “Glad they laid eggs!”

The DEC says that monarchs have wings that look like stained glass, typically with relish-orange coloring and apparent black veins. Monarchs contribute to the decline of the milkweed plants because it is their main food source. These plants, however, were planted especially for the caterpillars to eat.

While growing fat on a diet of milkweed, the caterpillar integrates the plant’s toxins into its own body, giving it a notoriously bitter taste even as an adult, nectar-sipping butterfly.

All of this eating serves another, more spectacular purpose. The pressure is on caterpillars during this time of year to finish fattening up, shedding their skins, forming chrysalises, and emerging as adults. In late August, monarch butterflies begin a vast round-trip migration to Mexico. They are the only butterflies in the world to make a round-trip, two-way migration like this.

Park visitors are feeling the butterflies’ excitement. Some are taking caterpillars and some wild milkweed home or to classrooms to let children watch the caterpillars’ metamorphosis.

“We raised one and set her free,” commented Vinny Pac Boo on the Letchworth post. “We have been trying like crazy to get more with the milkweed plants, but we aren’t having any such luck.”

Monarch butterflies are found throughout New York State, but are especially common in Albany Pine Brush Reserve in Albany County, Central Park in Manhattan, and Fire Island National Seashore in Suffolk County.