Two-tailed swallowtail butterflies (Papilio multicaudata) evolved to rely on chokecherry (Prunus) as caterpillar host plants, while adult butterflies get nectar from thistles, milkweeds, California buckeye, lilac and others.
The upper surface of the male forewing has narrow black stripes and each hindwing has 2 tails. Wingspan is 3-1/2 to 5 inches.
These photos were taken in July and August.
Two-tailed swallowtail butterfly on wavyleaf thistle
Two-tailed swallowtail butterfly
nectaring on cut-leaf
penstemon
Two-tailed swallowtail butterfly
with pale tiger swallowtail at Lake Roosevelt
Two-tailed swallowtail butterfly
nectaring on spreading dogbane
