Our species profile for this issue is the Chalcedon Checkerspot, Euphydryas chalcedona. The Chalcedon Checkerspot belongs to the family Nymphalidae, a huge worldwide family with great diversity. Washington’s checkerspot group includes nine species in three different genera, Chlosyne, Phyciodes and Euphyd1yas. Of these, the species within Phyciodes are called crescents, and, while both Chlosyne and Euphydryas are called checkerspots, they are not extremely closely related, and only Euphydryas has a checkered appearance ventrally.

Within Euphydryas (u-phid’-ree-us), we have three very closely related species-the Anicia, Chalcedon and Edith’s Checkerspots. These three species have a complex orange, black and white patterned appearance dorsally, while ventrally they are generally pale orange with rows of white spots outlined in black, giving a checkered appearance. Hence the name “checkerspot”.

The Chalcedon Checkerspot ranges across North America west of the Rocky Mountains, from British Columbia to southern California and probably into Baja

Mexico. In Washington, chalcedona occurs in four distinct, separated areas. The largest area, encompassing three subspecies, straddles the southern Cascades and foothills from King and Kittitas Counties south into Oregon. Another population and different subspecies occurs in the northern Olympics. Other isolated populations occur in the far northeast (Pend Oreille County) and southeast (Blue Mountains), encompassing a total of four subspecies in the state. The species is absent from most of the Columbia Basin and from the western Washington lowlands. To the north, Chalcedon is replaced by the Anicia Checkerspot and is absent there, except for Pend Oreille County.

The Chalcedon Checkerspot prefers open forests in mountainous areas, extending into the edge of the sagebrush steppe, generally avoiding the driest parts of the state. The species can be very abundant during summer, especially along unpaved roads in open forest and flowery meadow areas where penstemons occur. The Chalcedon Checkerspot larval food is primarily penstemons, but also indian paintbrush, snowberry and plantain.

Adults can be found through much of the summer, depending on elevation. Females oviposit clusters of eggs on the food plant leaves, and the eggs hatch in late summer. The black and orange spiny larvae are initially communal, living in clusters in webbed nests of silk and leaves, overwintering in the nests as small second or third instars. In the spring the larvae disperse to a few per plant, and grow to the final instar, pupating in late spring or early summer. The hanging chrysalis is attractive, white and heavily speckled with contrasting black spots. Adults emerge in early to mid summer.

Euphydryas checkerspots are readily recognized by the straight leading edge of the forewing. In the related Chlosyne checkerspots and Phyciodes crescents, the leading edge of the forewing is strongly and broadly curved adjacent to the body. Of the three Euphydryas species, the Edith’s Checkerspot can be identified by details of the lines on the ventral hindwing. One of these lines, known as the “editha line”, has red coloration on both sides, while the corresponding line on the other two species is white on at least one side. Also, dorsally the Edith’s has a sharper, crisper appearance. The last two species, chalcedona and anicia, are inseparable in the field-indeed NABA has combined the two species into one, named the Variable Checkerspot. These two species cannot be separated based on the amount of orange or black dorsally, as both species are highly variable.

Anicia and chalcedona differ in details of the male genitalia, and can be separated by laboratory dissection. Based on years of sampling and dissection by Jon Pelham, we know the species are fairly well separated geographically in Washington as follows:

I. Only chalcedona occurs west of the Cascades, with the exception of Whatcom County where only anicia occurs.

• In eastern Washington, only anicia occurs north of Kittitas County, with the exception of Pend Oreille County where only chalcedona occurs.
• In Kittitas, Yakima and Klickitat counties, both species occur. In the mountainous areas these will be chalcedona. But in the springtime in sagebrush areas both species can occur and cannot be field separated.
• In the Blue Mountains both species occur and cannot be field separated.

Photos by Dave Nunnallee

G’num2002Vol3No1