# Pipevine swallowtail (Battus philenor) > A large, mostly black swallowtail butterfly whose caterpillars feed on toxic pipevine and whose adults show metallic blue on the hindwings. Source: https://insectscanner.com/species/pipevine-swallowtail/ (updated 2026-10-10) ## Is it dangerous? **Toxic if eaten.** Pipevine swallowtail adults and caterpillars are not dangerous to touch. Caterpillars sequester toxic aristolochic compounds from pipevines, which makes them and adults distasteful and potentially toxic if ingested. Do not eat caterpillars or butterflies; wash hands if you handle them and then touch food. There is no venom and they do not sting. **Pets:** Toxic if eaten. Pets (dogs, cats) should not be allowed to eat large numbers of caterpillars or butterflies because the plant-derived toxins can cause gastrointestinal upset. Brief investigative mouthing is unlikely to be fatal but avoid ingestion. ## Quick facts - Scientific name: Battus philenor - Also called: Blue swallowtail - Order: Lepidoptera (Butterflies and moths) - Family: Papilionidae (Swallowtails) - Size: Wingspan about 70-130 mm - Colours: Black, Iridescent blue, Orange, Red - Habitat: Open woods, edges, meadows, gardens and areas where Aristolochia (pipevine) grows - Range: Eastern and western North America (throughout much of the United States), Mexico and parts of Central America; distribution follows availability of pipevine host plants - Active: Spring through autumn (multiple broods in warmer regions); active during daylight, especially late morning to afternoon - Lifespan: Adults live about 2-4 weeks in the wild (individual lifespan varies with season and conditions) - Effect on plants: Host-specific herbivore - Pest: no ## Overview The pipevine swallowtail is a medium-to-large North American swallowtail butterfly. Larvae feed almost exclusively on Aristolochia species (pipevines) and sequester the plants' toxic compounds, making the caterpillars and adults distasteful to predators. Adults patrol sunny edges, meadows and gardens for nectar and are often seen from spring through autumn where host plants occur. They are not harmful to people and are valued by gardeners for their striking appearance and role in local ecosystems. ## How to identify it Adults are mostly black to very dark brown with a prominent iridescent blue or blue-green wash on the upper side of the hindwings in males and often less intense in females. The underside of the hindwing shows a row of bright red or orange spots near the margin. Forewings are unmarked or have faint blue scaling. The species usually has small tail-like extensions on the hindwings. Caterpillars are plump, dark brown to black (sometimes reddish), with rows of long fleshy tubercles, the ones along the back tipped orange-red. Chrysalids (pupae) are green or brown, angular and attach to stems or sheltered surfaces. - Large black swallowtail with a pronounced iridescent blue patch on the upper hindwing in males - Row of bright red or orange spots along the underside of the hindwing - Association with pipevine (Aristolochia) on which caterpillars feed - Relatively small tail-like extensions on the hindwings (less pronounced than some other Papilionidae) ## Lookalikes - **Spicebush swallowtail** (Papilio troilus): Spicebush swallowtail has a row of pale spots along the upperside margins and two rows of orange spots on the hindwing underside with a blue band between them; its caterpillars have false eyespots and feed on spicebush and sassafras. - **Red-spotted purple** (Limenitis arthemis astyanax): A non-toxic mimic with similar iridescent blue-black upperwings and orange spots below, but it has no tails and its wings are more rounded; caterpillars feed on cherry, willow and poplar. - **Black swallowtail** (Papilio polyxenes): Another mimic; black with rows of yellow spots on the upperside, an orange eyespot with a black centre near the hindwing tail, and caterpillars that feed on carrot-family plants. ## Life cycle - **Egg:** Small, round, reddish-orange eggs laid singly or in small groups on pipevine leaves and stems. - **Larva (caterpillar):** Several instars. Early instars are gregarious and reddish-brown; later instars are larger, dark brown to black with orange-tipped fleshy tubercles and more solitary, feeding heavily on pipevines while sequestering toxins. - **Pupa (chrysalis):** Chrysalis attached to a stem or sheltered surface; usually camouflaged and angular-looking, overwintering in colder regions if timing allows. - **Adult (butterfly):** Winged stage that feeds on nectar, disperses, mates and lays eggs; multiple broods possible in warm areas. ## Diet and predators - Young eat: Leaves of Aristolochia species (pipevines) and related plants that contain aristolochic acids - Adults eat: Nectar from a variety of flowers (phlox, thistles, milkweeds, lantana and other nectar-rich garden flowers) - Predators of the young: Birds, parasitic wasps and flies, and predatory insects, though many predators avoid them because of sequestered toxins - Predators of adults: Birds and spiders, but adults are often avoided by predators because of the toxins acquired as caterpillars; some predators still take individuals ## Effect on plants and gardens Larvae feed almost exclusively on Aristolochia species (pipevines). Heavy local feeding can defoliate individual plants but populations are usually in balance with host availability. Adults are nectar feeders and can help pollinate garden flowers. ## Where and when to find it Search pipevine (Aristolochia) plants for eggs and caterpillars. Adults visit sunny edges, meadows, gardens and flower patches for nectar. - Best time: Spring to autumn; mid-morning to late afternoon on warm, sunny days. - Tips: Look for adult males patrolling open areas and for clustered early-instar caterpillars on new pipevine leaves. Use a telephoto lens or stay still and quiet to photograph feeding or ovipositing butterflies. ## Fun facts - Pipevine swallowtail caterpillars store toxins from pipevines that make both caterpillars and adults unpalatable; this provides protection from predators. - Because they are toxic, other non-toxic butterflies may mimic the pipevine swallowtail's appearance to gain protection (Batesian mimicry). - In some parts of its range the pipevine swallowtail has several broods per year; in cooler regions it may have only one. ## Frequently asked questions ### Do pipevine swallowtails sting or bite? No. Adults are harmless; they do not sting or bite. Caterpillars do not sting, though they can be handled carefully if needed. ### Are pipevine swallowtails poisonous? Only mildly. They are toxic to predators because the caterpillars sequester aristolochic acids from pipevine host plants. They are not harmful through casual contact, but should not be eaten. ### Why is a pipevine swallowtail in my garden? If you have pipevine (Aristolochia) or nearby populations, this species will visit for oviposition and adults will visit nectar flowers in sunny gardens. ### How can I attract pipevine swallowtails? Plant native Aristolochia (pipevine) as larval host plants and provide nectar plants such as phlox, milkweed, thistle and lantana. Provide sunny spots and avoid broad-spectrum insecticides. ### How do I get rid of them if they are eating my pipevine? They are not considered pests in most gardens. If you must reduce numbers, remove eggs by hand or relocate caterpillars to another pipevine. Avoid pesticides; targeted, minimal actions are most humane and effective. Remember populations depend on host plants. ### When can I see pipevine swallowtails? They are most commonly seen from spring through autumn; in warm regions they can be observed most of the year. Active during daylight, especially late morning and afternoon. --- More about this species: [iNaturalist](https://www.inaturalist.org/taxa/49972), [Wikipedia](https://en.wikipedia.org/wiki/Battus_philenor). Identify insects and spiders from a photo with the Insect Scanner iPhone app: https://apps.apple.com/app/id1543946563?pt=126685406&ct=web-markdown&mt=8 Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.