The Wisconsin Entomological Society (WES) has noted a marked rise in Clouded Sulfur numbers, New Richmond News reported.
Especially common in agricultural areas, the species does not need any special conditions to flourish, so is therefore fairly well established.
However, some species of butterfly do need help as the general trend is for numbers to be falling.
Butterflies have enjoyed a strong 2010 in comparison to last year, WES enthusiast Kyle Johnson told the news provider.
"I’m not sure why this year would be so good. Perhaps the early spring warm up, without many drastic late freezes, would be one reason."
Gardeners who wish to attract the winged creatures to their green space should provide sunlight and water and avoid pesticides, which can harm butterflies, birds and insects.
In other news, the Times Standard recently recommended that horticulture lovers water deeply and early in the morning to make the most efficient use of their hoses.