Troup extension agent: The rise of cloudless sulphur butterflies

Published 12:00 am Friday, September 16, 2016

We had caller this week ask about the identity of the yellow butterflies fluttering everywhere. I hadn’t noticed much until driving from Athens to LaGrange via the scenic route. That’s when I noticed that there were quite a few. I’m grateful that we have such observant citizens in Troup County.

This pretty yellow butterfly is commonly known as the cloudless sulphur.

They are so prevalent this time of year because they’re migrating much like the monarchs but not in such large numbers. They migrate from north to south and are seen on roads going east west. They’re on their way to Florida just like the snowbirds from up north.

They love the latitude of Gainesville and are known to be big Gator fans. They usually over winter and survive unless the temperatures fall below 20 degrees Fahrenheit.

As they fly their migratory routes, they prefer to fly over obstacles such as a house than around them. They do not deviate from their route. They prefer to roost on cloudless or dark nights on yellow foliage to help camouflage them from hungry birds.

Their long tongues facilitate their nectar collection. They do indeed prefer plants with yellow flowers.

Cloudless sulphurs are common throughout the Southeastern states and can be found as far north as Canada. They may even stray to the Midwest and Colorado. They can also be found as far south as South America and the West Indies.

Females are pale yellow or white with a narrow black border on the wings and a dark spot in the middle of their front wing. Males are described as being dimorphic, which means that they exhibit different seasonal characteristics. Their winter form is larger with darker markings ventrally. Their larvae are similar to a tomato hornworm. They are green with yellow lateral line and blue patches with black bristles in the blue patches.

The best way to control their larvae is by hand-picking. It is not necessary to control them with insecticides.

The father of modern taxonomy. Carl von Linne´ (Linnaeus) named the butterfly, Phoebis sennae. The genus is named for the Greek god Apollo’s sister Phoebe. The specific epithet, sennae for the genus Senna. The reasoning being that this butterfly prefers those plants as a larvae host.

The University of Florida noticed a decline of the cloudless sulphur butterfly from 1984 to 2000. They attributed this to the reduced planting of soybeans, which the weed commonly known as coffee weed or sicklepod loves to infest. Sicklepod is in the Senna genus. Better herbicide control may also be a culprit.

The cloudless sulphur butterfly is indeed a welcome attraction to our fall color.

What’s going on in Extension?

Sept. 19: Home Gardening, Food Production and Nutrition Seminar will be held from 9:30 3:15 PM at the Chipley Co-op in Pine Mountain. You must pre-register with Harris County Extension at 706-628-4824. If you have any questions or concerns, stop by or call the office.

Sept. 19: Troup County Association of Beekeepers Meeting, 7 the Ag Center. Jim Quick, master beekeeper will be our guest speaker.

By Brian Maddy

Contributing columnist

Brian Maddy is the ANR Agent for Troup County Extension. The Troup County Extension office is located at 114 Church St. in LaGrange and may be reached at 706-883-1675, Monday–Friday 8 a.m.–noon and 15 p.m.