King Swallowtail

Papilio thoas, the king or thoas swallowtail, belongs to Papilionidae. Some taxonomic resources use the generic combination Heraclides thoas. [1][2]

A diagonal row of square yellow spots crosses the dark upper forewing. The hindwings are tailed. The North American account gives a wingspan of 10.5–12.8 cm. [1]

The North American account gives a range from south Texas to Brazil, with very rare strays in Kansas and Oklahoma. Habitats include tropical forest at middle elevations and lowland forest edges. [1]

Larvae resemble bird droppings and rest exposed on leaves. [1]

Recorded larval hosts include Citrus, Zanthoxylum americanum and Ptelea trifoliata in Rutaceae, with additional records in Piperaceae. Adults take flower nectar, including Lantana. [1]

The account records year-round flight in the tropics and an April–July flight period in south Texas. Adults visit flowers for nectar. [1]

The larval osmeterium is a retractile, Y-shaped organ behind the head. A 2018 study distinguished protective epidermal cells on its tubular arms from secretory cells in the gland. Its secretion contained several terpenoid compounds, including bisabolene forms, β-pinene and farnesol. [3]

The larva combines a bird-dropping-like appearance with a deployable secretory organ. Mechanical disturbance elicits secretion from the eversible osmeterium. [1][3]

Papilio thoas and Heraclides thoas represent alternative generic arrangements of the same named species. The osmeterium study uses Heraclides thoas. [1][2][3]

The North American account lists the global rank G5, meaning demonstrably secure under its conservation ranking system. [1]

The diagonal row of square forewing spots and tailed hindwing outline are prominent pattern landmarks. [1]

Yellow pattern elements remain distinct against dark wing fields. The celestial frame surrounds the specimen without interrupting its tailed outline. [1]

Keep the wings and tails protected from handling, direct light and moisture. A closed enclosure helps prevent dust and pest damage. [5]

Which stage has an osmeterium? The larva has this retractile, Y-shaped defensive organ behind the head. [3]

Why are Papilio and Heraclides both used? The names place the same species in different generic classifications. [1][2]

The North American account documents identification, hosts, seasonality and range. Martínez and colleagues’ 2018 study describes the anatomy and chemical secretion of the larval osmeterium. [1][2][3]