“Vanessa cardui,” one of the first scientific names I memorized, because these are so common here. From BugGuide, http://bugguide.net/node/view/2649#range » “Worldwide, except South America and Antarctica, irruptive--sometimes not present in a given locality for several years then abundant for one or more years. Presumed to be a stray in Australia, where replaced by very similar and closely related Vanessa kershawi, which is sometimes treated as a subspecies of V. cardui.”
Retired economics professor (“dismal scientist”). Married 40+ years to the love of my life; we have two grown daughters, both married, two granddaughters and a...