Bug FAQEastern Giant Swallowtail
Papilio cresphontes · Order: Lepidoptera · Family: Papilionidae
Also called: Giant Swallowtail, Orange dog
Source: Wikipedia
Adults have black wings with yellow lines and a small red patch on the underside that sets them apart from similar swallowtails. Females average a 14 cm wingspan and males about 15 cm, with the largest reaching up to 19 cm.
Source: Wikipedia
Size
Females average 5.5 in (14 cm) wingspan, up to 6.9 in (18 cm); males average 5.8 in (15 cm), up to 7.4 in (19 cm).
Source: Wikipedia
Is it a pest in the house?
Caterpillars, called “orange dogs” or “bird-poop caterpillars,” feed on all citrus varieties and can heavily defoliate new growth and young trees. Mature citrus trees usually suffer little damage.
Source: Wikipedia
How to get rid of it
Biological insecticides like Bacillus thuringiensis and chemical sprays are used to protect trees from the larvae. Methionine has shown promise as a non-toxic pesticide against the caterpillars.
Source: Wikipedia
Where it lives
In the U.S. they are found mainly in deciduous forests and citrus orchards. They can survive winter only in Florida and the deep South.
Source: Wikipedia
What it eats
Adults sip nectar from plants such as lantana, azaleas, bougainvilla, soapwort, sweet woodruff, goldenrod, Japanese honeysuckle, and swamp milkweed.
Source: Wikipedia
Life cycle
Females lay single eggs on the tops of host plant leaves rather than in clusters.
Source: Wikipedia
When you see it
Western populations once thought to be this species are now classified as a separate species, Papilio rumiko, based on DNA evidence.
Source: Wikipedia
Where it comes from
They are common across the United States, reaching southern New England and southern Canada. Their range also includes parts of Mexico, Jamaica, and Cuba.
Source: Wikipedia
Lookalikes
A small red patch on the ventral wing within a blue band distinguishes it from the similar Schaus' swallowtail.
Source: Wikipedia
Where it is found in the US
Recorded in 43 of 51 states and DC. Most records: Florida, Texas, Vermont, Illinois, New York, Michigan, Louisiana, Wisconsin.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
How can I stop the caterpillars from damaging my citrus trees?
Apply Bacillus thuringiensis or approved chemical insecticides, and consider methionine as a non-toxic option.
Source: Wikipedia
What do the adult butterflies look like?
They have black wings with yellow stripes and a tiny red spot on the underside within a blue band.
Source: Wikipedia
Where are eastern giant swallowtails found?
They live across the eastern U.S., into southern Canada, and also in parts of Mexico, Jamaica, and Cuba.
Source: Wikipedia
Do the larvae affect mature citrus trees?
Mature trees are generally not significantly harmed by the caterpillars.
Source: Wikipedia
Same family (Papilionidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Papilio_cresphontes
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.