Species: Oriental cockroach (Blatta orientalis); American cockroach (Periplaneta americana); Florida woods cockroach (Eurycotis floridana); Giant water bugs (family Belostomatidae)
Side by side
| Oriental cockroach | Palmetto bug (the larger cockroaches) | Giant water bug | |
|---|---|---|---|
| What the name covers | Penn State says water bug is the nickname for this one species indoors | Florida applies palmetto bug to the American, Australian, brown and smokybrown cockroaches | Missouri uses giant water bug for the true aquatic insects in this family |
| Adult length | About 1 inch, 25 mm | 1 1/4 to 2 inches, 31 to 51 mm | Up to 2 inches, 51 mm |
| Where it lives | Damp basements, floor drains, crawl spaces, at or below ground level | Generally outdoors; Florida says outdoor cockroaches do not survive well indoors | Ponds and sluggish water, breathing through a tube at the hind end |
| How it gets indoors | Moves in along plumbing and under door or window jambs | Migrates in or is carried in from outdoors | Flies in at night toward lights, sometimes landing in swimming pools |
| Why it matters | Penn State links cockroaches to gastroenteritis and to allergens in excrement and cast skins | Florida says removing these outdoor cockroaches is often all the control needed | Missouri says it can bite painfully if handled, hence the name toe-biter |
What to look for
- Size first. Penn State puts the adult Oriental cockroach at about 1 inch (25 mm). Florida extension gives the American cockroach as 1 1/2 inches (38 mm) and the Florida woods roach, the largest it lists, as 1 1/4 inches (31.75 mm).
- Color and finish. Penn State describes Oriental cockroaches as very dark brown, nearly black, with a somewhat greasy sheen, on both males and females.
- Wings. Female Oriental cockroaches have small, functionless, rudimentary wing pads, males have wings covering only about three quarters of the abdomen, and males are apparently unable to fly.
- Where it was found. Penn State places Oriental cockroaches at or below ground level, seldom on walls, in high cupboards or on the upper floors of buildings, and calls them less wary and more sluggish than the other species.
- Palmetto bug. Florida extension applies that name to the larger cockroaches, the American, Australian, brown and smokybrown, at 1 1/4 to 2 inches (31 to 51 mm), and says they are generally found outdoors and do not survive well indoors.
- A true water bug. Missouri Department of Conservation describes giant water bugs as brownish, oval and flattened, reaching 2 inches (51 mm), with clawlike forelegs for grabbing prey and long, oarlike hind legs for swimming.
Where and when
Penn State finds Oriental cockroaches under sinks and washing machines, in damp basements, floor drains and crawl spaces, usually at or below ground level, and notes they move into structures during drought in search of humidity. Their adult numbers peak in late spring or early summer. Missouri puts giant water bugs in ponds and sluggish water, surfacing to breathe through snorkel-like tubes at the hind end.
Does it matter?
Penn State reports that cockroaches spread filth from sewers and garbage onto food and food preparation surfaces, that gastroenteritis is the principal illness associated with them, and that their excrement and cast skins contain allergens linked to rashes, congestion and asthma. Missouri notes that a giant water bug can bite painfully if handled or trodden on, hence the name toe-biter. Penn State's first step is sanitation and sealing harborages.
Related guides
- Camel cricket: A camel cricket is the humpbacked, wingless, long-legged cricket that jumps out of a basement corner.
- House centipede: The fast, many-legged thing in a bathroom is almost always a house centipede.
- Silverfish: A silverfish is a wingless, flat, teardrop-shaped insect covered in silvery scales, with long thread-like antennae and three tail-like appendages at the rear.