Les Harrison is the Wakulla County Extension Director
Notoriety can be a positive occurrence, when events go as planned or hoped. Such is the case with the Monarch Butterflies.
These colorful insects have garnered the interest and concern of thousands, if not millions, of people who are worried an age-old annual pilgrimage to winter grounds in Mexico may soon come to an end. Milkweed has morphed from an agricultural nuisance to a highly prized ornamental, and the means of “Saving the Monarchs.”
For the uninformed, Monarchs lay their eggs on the toxic Milkweed and their caterpillars feed on it until cocooning. They, and a few other insects, get the benefit of Milkweed consumption by having a bitter taste to any prey species which is tempted to make a quick snack from an unlucky member of the migrating flock.
Not as generally known, there is another butterfly common to Wakulla County which is migrating at the same time as the Monarchs. The Cloudless Sulphur, Phoebis sennae, is one of the most common native butterflies and is particularly prominent during its fall southward migration.
The fall migration of the Cloudless Sulphurs is the easiest butterfly migration to observe in the southeastern United States. On pleasant autumn days even a casual observer will notice these bright yellow butterflies crossing the terrain within easy view, usually from north to south.
The seasonal migrations of Cloudless Sulphurs and Monarchs are similar with each species relocating from large and favorable summer breeding areas. The northern habitats can produce fatal low winter temperatures, so the strong flyers head to more favorable climates to the south.
In the spring of the following year, surviving adults head northward and soon repopulate the summer breeding areas. In both species, the northward migration is evidenced by the reappearance each summer in the breeding areas they abandoned the previous fall.
The Cloudless Sulphurs migrate through open areas at an altitude of about 10 feet above ground. When they encounter a major obstacle, such as a building, they rise and fly over it rather than deviating from their migratory path.
Frequently, the Cloudless Suphurs can be seen well under their 10-foot migration altitude ceiling. Closer to the ground it is easier to identify the autumn blooms which contain nectar, their high carbohydrate meal of choice.
Red flowers seem to be the preferred bloom for these late season travelers. In Florida, they frequently dine at the red morning-glories, scarlet creeper (Ipomoea hederifolia), and cypressvine (Ipomoea quamoclit), and at the scarlet sage, (Salvia coccinea).
In some years, Cloudless Sulphur butterflies have been reported to have successfully survived winter in Wakulla County and other North Florida locales. In exceptionally frigid winters, which produce temperatures below 20 degrees, the Cloudless Sulphur holdovers are likely to expire from the lethal thermometer readings.
At night and on dark, cloudy days adult Cloudless Sulphurs roost alone on leaves. They are very choosey about just the right place when settling in.
An adult preparing to roost makes an erratic flight around a potential tree or shrub, stopping briefly at times, then flying about some more, and typically coming to rest on a yellow or reddish leaf clustered with other leaves.
Although the adults are brightly colored and easy to see when flying, they disappear quickly against similarly colored leaves in the shade. The roost site is commonly low to the ground in shrubs with lots of foliage.
This behavior is thought to help prevent attacks from predators, primarily birds. No doubt the Cloudless Sulphurs appreciate the recognition and notoriety, except when it gets them eaten.