August Is The Season For Butterfly Watchers This common sulphur butterfly feasts on the nectar of a thithonia flower, also called the Mexican sunflower. The sulpurs and the whites flashing sunshine in their wings are appearing on the August scene in great number and as though on cue. There are no other butterflies in the entire Northern Hemisphere as abundant as these easily recognized creatures on sunny days. Living near the open countryside where especially the common sulphurs abound, it’s an easy matter telling the males from the females. Both sexes have wide dark borders on the upper wing surfaces, but those black borders of the female contain light spots within the black zone, well separated from the yellow or orange-yellow ground color. This is one of the several species, along with the swallowtails, for example, that frequently forms large concentrations referred to as ‘puddles,’ or as the lepidopterist would say, "the sulphurs are puddling." Something has happened during the past hundred years or so to add considerable confusion to the identification of the sulphur butterflies. A different species of the south, the orange sulphur or alfalfa butterfly, gradually moved northward and began to interbreed with the commons. Today you might call it a "duke’s mixture." To compound the confusion it is quite common for there to be albino or white females of both species. This hybridization presents challenges (and headaches) to the lepidopterists, those who study moths and butterflies. If you think you have a common sulphur in hand, look on the underside of the hindwing. There should be a reddish or pinkish spot with a silvery center. It is quite likely that the very name butterfly was derived from the buttery appearance of the sulphur butterflies, as common in northern Europe as they are here. The yellow pigments of most of the sulphurs are built up from waste products within the insect. It will be a simple matter to find a dead sulphur, perhaps on the radiator grill of your car. Place the butterfly in a white saucer containing a tablespoon of water and another of diluted ammonia. Most of the yellow will dissolve leaving the wings nearly colorless. Their life span is ephemeral, a few weeks at most. The encircling mating flights are easy to locate and watch. Eggs are laid on the host plant, either clover or alfalfa but preferably white clover. The green caterpillars feed and grow for about three weeks before forming their chrysalids. Adults will emerge in approximately 10 days. There are usually at least three broods here during a summer and the chrysalids of the third generation will overwinter, the adults emerging the following summer. A relative, the cabbage butterfly, is also on the wing now. This plain white butterfly is no friend to the gardeners. Its eggs are laid on members of the mustard family including radishes, Brussels sprouts, cabbages, turnips, kohlrabi and broccoli. Shortly after, the eggs hatch and the caterpillars eat merrily away on the leaves of these vegetables. These pesky butterflies were unknown in this country a little over 120 years ago. How they got here from Europe is not known but they are here to stay. They were first seen in Wisconsin in 1879. With most of their natural enemies left behind in Europe they have proliferated here. It is also easy to sex the rather drab white cabbage butterflies. The male has one black spot on each forewing while the female has two black spots. Prior to the arrival of the cabbage butterflies in North America, which is now the number one butterfly here in population, a native white butterfly called the mustard white was very common. In fact experts claim that in the early days it was the most abundant species in eastern North America. Gradually the cabbage butterfly replaced the mustard whites which retreated to less desirable sites including the mountains and shaded forests. The mustard whites of early summer have very distinctive dusky veins, or marbling, that is lacking in the cabbage whites. The second generation of summer is not quite as clearly marked as the first. The flight of the mustard whites is closer to the ground and at a slower pace. Don’t expect to find this uncommon creature in open fields or gardens mixed in with the cabbage butterflies. Mustard whites lay their eggs on rock cress, also called sand cress, Arabis lyrata (AIR-a-bis lie-RAY-ta). The Ridges Sanctuary, having a good population of sand cress along trails with sunny openings within the shaded forest, is a perfect habitat for the beautiful mustard white butterflies. Varying temperatures from spring into fall affect the color and size of the whites and sulphurs. The cold-weather forms in spring and fall tend to be smaller than those of mid-summer. Enjoy the blue skies of late August and early September liberally complimented by swirling masses of yellow butterflies. Delight in them as they flutter by! This column appeared in the Door County Advocate on 08/23/2002. © Copyright 2002 Roy Lukes. All rights reserved.