A Simple Field Mark for Identifying Fritillaries

[George DeWolf]

When you’re new to butterflies, it can be very difficult to distinguish those that are predominantly orange and black dorsally (on the upper side). Here in New Hampshire, by my count, we have at least 17 such butterflies: the five fritillaries; the two crescents (the Pearl and Northern); the two checkerspots (the Harris’s and Baltimore); the four anglewings (the Question Mark and the Eastern, Green, and Gray Commas); the three Vanessa species (the two Ladies and the Red Admiral); and, of course, the Monarch. There are others, but these are the most common ones that come to my mind.

One place to start, if you’re confused by this array of orange and black butterflies, is to determine whether you’re looking at a fritillary—or not. All of our fritillaries, whether they’re one of the larger so-called “greater frits” (the Great Spangled, Atlantis, or Aphrodite) or one of the smaller “lesser frits,” share one feature that distinguishes them from all other New Hampshire butterflies (whether predominantly orange and black dorsally or not), provided you get a look at the upper side of an untattered forewing: they all have a row of seven black dots along the outer margin of the forewing. No other group of New Hampshire butterflies has this distinctive field mark.

I’ve taken to calling fritillaries the “squiggly line” butterflies because they all, to varying degrees, have a set of squiggly lines on the dorsal forewing near the attachment point of the wing. Going forward, I'm likely to use the mnemonic “Seven-Up on the forewing” to help remember that all frits have seven black dots arranged submarginally (near the outer margin) on the dorsal forewing.

This can be a quick and useful way to narrow down the possibilities when trying to identify this confusing array of orange and black butterflies. Hope this helps some of you.

George