Florida woods cockroach: about 150 days egg to adult; adults live over a year (UF/IFAS). Smokybrown: about 600 days to adulthood; adults average 215 days (UF/IFAS). American: about 600 days to adulthood; adults 90–706 days (Ebeling; UF/IFAS). All three are called palmetto bugs in the southern US (UF/IFAS; Texas A&M).
Palmetto bug lifespan
"Palmetto bug" isn't one insect, so the palmetto bug lifespan depends on which cockroach you've met. The three that carry the name in the southern United States all live a long time for insects:
- Florida woods cockroach — about 150 days from egg to adult, and "Adult lifespan exceeds one year" (UF/IFAS). That's well over a year and a half in total.
- Smokybrown cockroach — about 600 days to grow up, then "an average of 215 days" as an adult (UF/IFAS gallery), or 3–9 months (Texas A&M).
- American cockroach — about 600 days to grow up, then 90–706 days as an adult (Ebeling); UF/IFAS says adults "can live up to one year".
So the lifespan of a palmetto bug runs from about a year and a half to more than three years, counted from the day its egg case was laid. Most of that time is spent as a wingless nymph hiding in mulch, drains or wall voids — the big, winged adult you see on the kitchen floor at night is the last stage of a long life. The identifier above narrows it down to one species and gives its lifespan of palmetto bug adults and nymphs from the same data as our cockroach lifespan calculator.
How long does a palmetto bug live indoors?
How long does a palmetto bug live once it's inside? That depends on the species more than on the house. The Florida woods cockroach "does not live long inside structures" (UF/IFAS gallery) and "has not been shown to commonly colonize inside structures" (UF/IFAS IN915): it feeds mainly on decaying plant matter, which a house doesn't offer. American cockroaches, by contrast, can live and breed for years in basements, drains and commercial buildings. Smokybrowns sit in between, breeding mainly outdoors and in attics and eaves.
What is a palmetto bug? One name, several cockroaches
What is a palmetto bug? It's a nickname, used mostly in Florida and along the southeastern and Gulf coasts, for any large cockroach that shows up around homes. UF/IFAS explains that the name "may also describe any large cockroach that may frequently be encountered as a peridomestic pest" — around, rather than inside, buildings — and names three species:
- The Florida woods cockroach (Eurycotis floridana), "often referred to as a palmetto bug" in its native southeastern range. UF/IFAS's own fact sheet is titled "Florida Woods Cockroach (AKA Palmetto Bug)". It also goes by Florida stinkroach and skunk cockroach, for a reason explained below.
- The American cockroach (Periplaneta americana), "often called a 'palmetto bug'" (UF/IFAS gallery). Texas A&M says American cockroaches are "also known as waterbugs or palmetto bugs".
- The smokybrown cockroach (Periplaneta fuliginosa), "also often called a 'palmetto bug'" (UF/IFAS gallery).
Where you are matters. The Florida woods cockroach lives only in "coastal Georgia, Alabama, and Mississippi, and throughout most of Florida" (UF/IFAS), so outside that strip a "palmetto bug" is almost certainly an American or smokybrown cockroach. The smokybrown is common across the southern states and "occurs north to the Midwest and in southern California" (UF/IFAS gallery), and the American cockroach is found worldwide. The name itself comes from where the Florida woods cockroach likes to hide: "under palmetto leaves on the ground", under bark and in tree cavities (Ebeling).
Palmetto bug vs cockroach: is there a difference?
In the palmetto bug vs cockroach question, the answer is that every palmetto bug is a cockroach — the name is regional, not scientific. Nicknames like this are old: in 1938, Purdue entomologists noted that German, American and Oriental cockroaches had all had the common name "water bugs" applied to them, "because of their frequent occurrence around sinks and water pipes" (Gould & Deay). What does differ between the species is how long they live, whether they fly and whether they can breed indoors, which is why the identifier matters.
How long do palmetto bugs live by species
How long do palmetto bugs live, side by side? The table uses the shared cockroach model at 24 °C (75 °F). "Egg to adult" is the time from a new egg case to a winged adult; "Total" adds the adult lifespan.
| Species | Egg to adult | Adult lifespan | Total from the egg |
|---|---|---|---|
| American cockroach Periplaneta americana | 7.1–33.8 months (up to 2.8 years) | 3–23.2 months (up to 1.9 years) | 10.1–57 months (up to 4.7 years) |
| Smokybrown cockroach Periplaneta fuliginosa | about 19.7 months (up to 1.6 years) | 3–9 months | 22.7–28.7 months (up to 2.4 years) |
| Florida woods cockroach Eurycotis floridana | 4.9–5.5 months | over a year (no upper figure published) | over 1.4 years |
Sources: Florida woods — UF/IFAS IN915 (egg case about 48 days at 30–36 °C, nymphs 100–120 days, egg to adult about 150 days, adults over a year). Smokybrown — UF/IFAS gallery (about 600 days to adult, adults average 215 days) and Texas A&M (adults 3–9 months). American — Ebeling, Penn State and UF/IFAS (see the American cockroach page). No source we read gave smokybrown development by temperature, so it isn't adjusted.
Florida woods cockroach lifespan
The florida woods cockroach lifespan is the least studied of the three, but UF/IFAS IN915 gives the outline. Eggs in the case take "approximately 48 days to hatch at 30°C–36°C"; nymphs go through six to eight moults and reach adulthood "within 100–120 days"; egg to adult "is estimated to be 150 days"; and "Adult lifespan exceeds one year". A female forms her first egg case after about 55 days as an adult and glues it to something like a decaying log. Each case is 13–16 mm long with a saw-toothed upper edge and holds 20–24 eggs (UF/IFAS). No upper limit for adult life has been published, so the identifier reports it as "over a year".
Adults are 30–40 mm long and up to 24 mm wide, reddish brown to nearly black, with only short leathery wing pads that "barely meet on the midline" and don't cover the abdomen (UF/IFAS). "Adults cannot fly" (UF/IFAS gallery), and the species is "slow moving".
Palmetto bug vs American cockroach
Because the American cockroach is one of the palmetto bugs, the palmetto bug vs american cockroach question usually means "is the big roach I found an American cockroach or the Florida woods kind?" Four clues settle it:
| Clue | American cockroach | Florida woods cockroach |
|---|---|---|
| Wings | long wings over the body; males' extend past the tip | short pads only; abdomen bare |
| Colour | reddish brown, pale or yellowish band around the shield | reddish brown to nearly black, no band |
| Shape | slender, 34–54 mm | broad and heavy, 30–40 mm long, up to 24 mm wide |
| Behaviour | fast; both sexes can fly | slow; can't fly; sprays a smelly liquid when disturbed |
| Where | sewers, drains, basements, commercial kitchens | mulch, woodpiles, rotting logs; firewood brought in |
Sources: UF/IFAS EENY-141, IN915 and gallery; Texas A&M; Ebeling. The smokybrown is the third look-alike: winged like the American but smaller (25–32 mm) and uniformly dark mahogany, including the shield behind the head (UF/IFAS). For the American cockroach's full lifespan and dated life cycle, see the American cockroach lifespan calculator.
Why palmetto bugs come indoors
All three are mainly outdoor insects in the South. The American, Oriental and smokybrown cockroaches "live mostly outdoors but may move indoors in search of food or water" (Texas A&M). The sources point to five triggers for why palmetto bugs come inside:
- Heavy rain. American cockroaches are rarely found in houses, "however infestations can occur after heavy rain" (UF/IFAS).
- Light at night. Smokybrowns are "good fliers and are attracted to light"; the species "readily enters structures through lit openings" (UF/IFAS gallery).
- Gaps and drains. The larger roaches "often enter a home or business through poorly sealed doors, roof soffits, or floor drains" (Texas A&M). Keeping drain traps filled with water blocks the sewer route.
- Hitching a ride. A Florida woods cockroach indoors is "typically a result of being transported indoors on another item, such as firewood" (UF/IFAS IN915).
- Shelter near the house. Smokybrowns live in "ground cover, mulch, palm fronds, soffits, eaves of attics, and tree holes" (Texas A&M); Florida woods cockroaches use storage areas, greenhouses and pump housings (UF/IFAS).
Practical, non-toxic steps follow from that: check the seals under doors and screen roof soffits, keep floor-drain and sink traps filled with water (Texas A&M), shake out firewood before bringing it in, and keep lights near doors off at night when you can, since smokybrowns fly toward light. Sticky monitors along walls near doors show where they're entering (Texas A&M). If they're breeding indoors, the cockroach removal timeline planner sets out a week-by-week plan.
Are palmetto bugs harmful?
Are palmetto bugs harmful? Not dangerous, but not harmless either. Cockroaches "also may transfer disease-causing organisms" (Texas A&M), and their droppings, saliva and shed skins contain allergens that can trigger asthma, especially in children (CDC; Penn State). The Florida woods cockroach adds a defence of its own: an oily secretion from a gland under its abdomen that is "harmful to skin and sensitive tissue such as the eyes". It can aim it, spraying from about 3 cm to as far as a metre, and it takes up to 30 days to refill the gland (UF/IFAS IN915). If you need to move one, use gloves or a container rather than bare hands, and keep it away from your face.
How this tool works
The identifier uses the same scoring method as the other insect identifiers on this site: each answer adds points to every species whose published description matches it, and "Not sure" answers add nothing.
- Clues and points: wings 3 points; region, size, colour, where you saw it and behaviour 2 points each (13 in total). Traits come from UF/IFAS, Texas A&M and Ebeling — for example, only the Florida woods cockroach has wing pads instead of wings, sprays a foul smell, and lives only along the Gulf coast and in Florida.
- Confidence: high needs at least 8 points and a lead of 3 or more; any "Not sure" answer caps it at medium.
- Lifespan: the winning species' adult lifespan and total from the egg at 24 °C, from the shared model — the same figures as the cockroach lifespan calculator. The Florida woods cockroach's adult life is "over a year" because no upper figure has been published.
Nymphs of all three are wingless, so answer the wing question "Not sure" for a small roach. If you can't decide, a local extension office can identify a specimen.
Frequently asked questions
How long do palmetto bugs live?
From about a year and a half to over three years in total, depending on the species: Florida woods cockroaches about 150 days to adulthood and over a year as adults (UF/IFAS); American and smokybrown cockroaches about 600 days to adulthood, then months to about two years.
What is the lifespan of a palmetto bug adult?
Florida woods: over a year (UF/IFAS). Smokybrown: an average of 215 days (UF/IFAS), 3–9 months (Texas A&M). American: 90–706 days for females at 29 °C (Ebeling).
What is a palmetto bug?
A regional name for large cockroaches seen around homes in the South: the Florida woods cockroach, the American cockroach and the smokybrown cockroach (UF/IFAS).
Is a palmetto bug a cockroach?
Yes. Every insect called a palmetto bug is a cockroach; the name is a nickname, not a species.
Is a palmetto bug the same as an American cockroach?
Sometimes. American cockroaches are often called palmetto bugs (UF/IFAS; Texas A&M), but so are Florida woods and smokybrown cockroaches. See the American cockroach lifespan page.
Can palmetto bugs fly?
American and smokybrown cockroaches can — smokybrowns are good fliers attracted to light (UF/IFAS). Florida woods cockroaches have only wing pads and can't fly.
Why does a palmetto bug smell bad?
If it's a Florida woods cockroach, it sprays an oily, foul-smelling defensive liquid that irritates skin and eyes (UF/IFAS IN915).
Are palmetto bugs harmful?
They can carry disease-causing organisms (Texas A&M), their allergens can trigger asthma (CDC), and the Florida woods cockroach's spray irritates skin and eyes (UF/IFAS).
Why do palmetto bugs come inside?
Heavy rain, lights at night, gaps around doors and soffits, floor drains, and firewood carried in (UF/IFAS; Texas A&M).
Do palmetto bugs live in houses?
Florida woods cockroaches don't live long indoors (UF/IFAS). American cockroaches can breed in basements and drains, and smokybrowns in attics and eaves.
These calculators give estimates from laboratory, extension and husbandry figures, for education. Real cockroaches vary with strain, food, humidity and temperature. Cockroach droppings, saliva and shed skins contain allergens that can trigger asthma, especially in children (CDC; Penn State) — for health questions, talk to a doctor. For a heavy infestation, contact a licensed pest professional or your local extension service. We name no products and give no pesticide doses.