Deciphering Butterflies: Yellow Swallowtails
Yellow swallowtails are the showstopper in many gardens. Big and beautiful, they are easy to see when present. However, as you wander westward in Nebraska, you have to be a little more discerning about exactly what yellow swallowtail you are looking at.
General Appearance – Large, 2 1/2 – 4 1/2 inches. Base color pale yellow.
Range – Statewide
Status – Common, found season long.
Dorsal – Yellow spots in the forewing marginal black band are rounded, oval shaped. Top spot on the black marginal band on the hindwing is orange. One pronounced tail on the hindwing. Females have extensive blue scaling inside the hindwing black marginal band.
Ventral –
Eastern Tiger Swallowtail species page
General Appearance – Large butterfly 2 3/4 – 4 inches. Base color pale yellow.
Range – Extreme western Nebraska, either as an overlooked resident or stray. One flight in June and July.
Status – Rare or extirpated, no reliable reports in over 50 years.
Dorsal – Yellow spots in the FW black margin not as large or rectangular as in the Two-tailed Swallowtail. Top spot on the HW margin yellow or lacking (orange in Eastern Tiger Swallowtail). One prominent tail.
Ventral –
Western Tiger Swallowtail species page
General Appearance – Smaller swallowtail, 2 1/2 – 3 inches.
Range – Found in the southwestern third of the state.
Status – Occurs sporadically, often absent for years at a time.
Dorsal – Basal portion of the forewing filled in with black as in the Anise Swalloowtail. The black eyespot on the hindwing touches the inner margin.
Ventral –
Old World Swallowtail species page
General Appearance – One of our largest butterflies at 3 1/2 – 5 inches Generally the Two-tailed Swallowtail is somewhat larger, with a darker yellow base color than the Eastern Tiger Swallowtail but neither of these are reliable traits.
Range – Found in the western half of the state.
Status – Common in the panhandle, becoming rarer eastward.
Dorsal -Yellow spots in the forewing marginal black band are rectangular. Two pronounced tails on the hindwing. Females have extensive blue scaling inside the hindwing black marginal band.
Ventral –
Two-tailed Swallowtail species page
General Appearance – Large butterfly 2 3/4 – 3 1/2 inches, but generally smaller than the Eastern, Western and Two-tailed Swallowtails.
Range -The panhandle region of the state.
Status – locally common in two flights from May to mid July.
Dorsal – Basal portion of the forewing filled in with black. Black eyespot on the hindwing centered, not touching the inner margin.
Ventral –
Anise Swallowtail species page
