The American cockroach (Periplaneta americana), also known as the palmetto bug or waterbug particularly in the southern United States (Cassidy and Hall 2002), is the largest common species of pest cockroach. It is native to Africa, and is a pest worldwide, especially in the tropics and subtropics. In Europe and other countries with cooler climates, the American cockroach is rarely found out of doors. It is often found in bakeries, warehouses, hotels, zoos, greenhouses, mines, sewers and ships. It scavenges for food but can survive long periods of starvation. Adults live for between 4 to 21 months and the eggs hatch in 4-12 weeks. Extensively modified from Wikipedia.
The American Cockroach, despite its name, is not native to North America but was most probably introduced via ships from Africa. It is currently worldwide in distribution.
(Smith & Whitman, 1992)
Biogeographic Regions: nearctic (Introduced ); palearctic (Introduced , Native ); oriental (Introduced ); ethiopian (Native ); neotropical (Introduced ); australian (Introduced )
Other Geographic Terms: cosmopolitan
Periplaneta americana adults are about 1 3/8 to 2 1/8 inches (34-53 mm) long. Their color is a reddish brown except for a submarginal pale brown to yellowish band around the edge of their pronotal shield (Pronotal shield - an expanded version of the top surface plate of the front segment of the thorax). Both sexes are fully winged. The wings of males extend beyond the tip of the abdomen, while females' do not. They are poor to moderately good fliers.
Early instars of P. americana nymphs are uniformly grayish brown dorsally, paler ventrally, and shiny. The cerci (cercus [pl. cerci]- One of a pair of dorsal appendages at the posterior end of the abdomen) are slender, and distinctly tapered from the base with length about 5 times the width. Later instars are reddish brown with lateral and posterior margins of the thorax and lateral areas (sides) of abdominal segments somewhat darker. The cerci are about the same as in the early instars. The widest segments are 2.5 times as wide as long. The antennae are uniformly brown.
The cockroach's walking pattern can be described as follows:
"The cyclic movement of a walking leg consists of two parts, the power stroke (also stance phase or support phase) and the return stroke (also swing phase or recovery phase). During the power stroke, the leg is on the ground where it can support and propel the body. In a forward-walking animal, this corresponds to a retraction movement of the leg. During the return stroke, the leg is lifted off the ground and swung to the starting position for the next power stroke."
(Cruse 1990; Cochran 1980; Smith & Whitman 1992; Bio-Serv 1998)
Other Physical Features: ectothermic ; bilateral symmetry
P. americana is found in many different habitats. Although they generally live in moist areas, they can survive in dry areas if they have access to water. They prefer warm temperatures around 84 degrees Fahrenheit and do not tolerate cold. They die at temperatures below 15 degrees Fahrenheit. These criteria are often met in large commercial buildings such as restaurants, bakeries, grocery stores, food processing plants, hospitals, etc., where cockroaches may infest food-storage and food-preparation areas, basements, and steam tunnels. They are also found, although not as commonly, in residences. During the summer months, they can be found outdoors in yards and alleys. In the United States this is the most common species found in city sewer systems. They can enter structures by being brought in, coming up from the sewer system via drains, or occasional mass migration from other structures, dumps, etc., during warm weather.
(Cochran, 1980; Smith & Whitman, 1992)
Terrestrial Biomes: savanna or grassland ; forest ; rainforest ; scrub forest
Roaches themselves will eat anything, including one another. There is very little organic material that a cockroach won't eat. The list includes bark, leaves, paper, wool clothes, sugar, cheese, bread, oil, lemons, ink, soap, flesh, fish, leather, other roaches (dead or alive), or their own cast-off skins and egg-capsules. Some of these items, such as cellulose, can not be digested by normal means. However, like cows and other grazing animals, cockroaches have a symbiotic relationship with a bacteria that allows them to digest such substances. Although they feed on many kinds of food, they show a particular fondness for fermenting food.
(Helfer, 1972; Boraiko, 1981)
cyst of Gregarina blattarum endoparasitises intestine of Periplaneta americana
Animal / parasite / endoparasite
Hammerschmidtiella diesingi endoparasitises intestine of Periplaneta americana
Animal / parasite / endoparasite
Leidynema appendiculata endoparasitises intestine of Periplaneta americana
Animal / parasite / endoparasite
Nyctotherus ovalis endoparasitises intestine of Periplaneta americana
Life History and Behavior
Female P. americana produce many different sex pheromones to attract a suitable mate. Examples of these attractive chemicals include periplanone-B, periplanone-A, germacradien-9-one, cresol, phenol, undecen, hexenal, cyclohexanedial, hexanoic acid, dodecalactone, pentanone, and octanone. Sperm transfer occurs through the use of a spermatophore, which is sometimes eaten by the female because of its protein-rich nature. (Spermatophore- Capsule or packet enclosing sperm, produced by males of several invertebrate groups and a few vertebrates). Once fertilization has occurred, a female forms oothecae, or egg sacs. Parthenogenesis or egg production without fertilization does occur, but eggs either fail to hatch, or produce only a few nymphs. The ootheca is a dark reddish to blackish brown; about 3/8" (8 mm) long, with length about1.5 times the width. The female deposits her ootheca within a few hours or up to 4 days after it is formed. It is dropped or glued with an oral secretion to a suitable surface, usually in a crack or crevice of high relative humidity near a food source.
On average, females produce 9-10 (range 6-14; maximum 90) oothecae, each containing 14-16 eggs. Developmental time (egg to adult) is greatly influenced by temperature, varying from 168-786+ days but averaging about 600 days under ordinary room conditions. During this time, they molt 10-13 times. Adult females live about 440 days (range 102-588; maximum 913) at ordinary room conditions(e.g. 70°F/20°C), but at 84°F/29°C, adult females live about 225 days (range 90-706), whereas adult males live about 200 days (range 90-362) at 84°F/29°C.
The development of P. americana is hemimetabolous, meaning there is no major metamophosis. The nymphs look very much like small adults.
Nymphs are given no parental care; hatchling roaches are left to fend for themselves. The nymph grows by molting and it goes through about 13 molts before it reaches the adult form. The next to last nymphal stage has wing pads, but only adult cockroaches have wings.
(Bell, 1981; Smith & Whitman, 1992)
Evolution and Systematics
The cuticle of cockroaches allows temperature-controlled variability of moisture loss via a waxy coat.
"It was shown by Ramsay (1935) that the cockroach owes its impermeability to water to a thin and apparently mobile layer of lipoid on its surface. At a critical temperature of about 30° C. this lipoid seems to undergo a change of phase, and it then allows water to pass freely through it. This interesting observation has never been confirmed on other insects. It forms the starting-point of the present study." (Wigglesworth 1945:97)
Learn more about this functional adaptation.
- Wigglesworth, V. B. 1945. Transpiration Through the Cuticle of Insects. Journal of Experimental Biology. 21(3): 97-114.
Molecular Biology and Genetics
Barcode data: Periplaneta americana
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Periplaneta americana
Public Records: 26
Specimens with Barcodes: 46
Species With Barcodes: 1
This species is considered a pest, and there are no efforts being made to conserve it.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Relevance to Humans and Ecosystems
This species is harmful to humans, and its impact on human health and economies is substantial. The greatest potential harm is an agent for disease transmission. American cockroaches can transmit a variety of bacterial diseases by feeding on contaminated material, and then contacting people's food. Cockroaches are also the fourth most common allergen. 50-60% of all atopic and asthmatic people show intense reactions to cockroach extract. Sensitivity to cockroach allergens may be as high as 79% in asthmatic children in severely infested homes. The species also has a psychological impact on humans, causing anxiety and stress due to embarrassment and physical invasion (Bio-Serv 1998; Cochran 1980).
The American cockroach (Periplaneta americana), also colloquially known as the waterbug, but not a true waterbug since it is not aquatic, or misidentified as the palmetto bug (see Florida woods cockroach for the differences), is the largest species of common cockroach, and often considered a pest. It is also known as the ship cockroach, kakerlac, and Bombay canary.
Despite the name, none of the Periplaneta species are endemic to the Americas; P. americana was introduced to the United States from Africa as early as 1625. They are now common in tropical climates because human activity has extended the insect's range of habitation, and are virtually cosmopolitan in distribution as a result of global commerce.
Cockroaches date back to the Carboniferous period. Cockroaches are thought to have emerged on the supercontinent Pangaea, or on Gondwana, the daughter continent of Pangaea. The cockroach made many adaptations over the years to be able to survive the major die offs to which many species succumbed.
American cockroach adults grow to an average length of around 4 cm (1.6 in) and about 7 mm (0.28 in) tall. They are reddish brown and have a yellowish margin on the body region behind the head. Immature cockroaches resemble adults except they are wingless.
The cockroach is divided in three sections; the body is flattened and broadly oval, with a shield-like pronotum covering its head. A pronotum is a plate-like structure that covers all or part of the dorsal surface of the thorax of certain insects. They also have chewing mouth parts, long, segmented antennae, and leathery fore wings with delicate hind wings. The third section of the cockroach is the abdomen.
The insect can travel quickly, often darting out of sight when someone enters a room, and can fit into small cracks and under doors despite its fairly large size. It is considered one of the fastest running insects.
In an experiment carried out at the University of California, Berkeley in 1991, a Periplaneta americana registered a record speed of 5.4 km/h (3.4 mph), about 50 body lengths per second, which would be comparable to a human running at 330 km/h (210 mph).
It has a pair of large compound eyes, each having over 2000 individual lenses, and is a very active night insect that shuns light.
The American cockroach shows a characteristic insect morphology with its body bearing divisions as head trunk and abdomen. The trunk, or thorax, is divisible in prothorax, mesothorax and metathorax. Each thoracic segment gives rise to a pair of walking appendage (known as legs). The organism bears two wings. The forewings, known as tegmina arises from mesothorax and is dark and opaque. The hind wings arise from metathorax and are used in flight. The abdomen is divisible into ten segments each of which is composed of dorsal tergites and ventral sclerites.
Risk to humans
The odorous secretions produced by American cockroaches can alter the flavor of food. Also, if populations of cockroaches are high, there will be a strong concentration of this odorous secretion. Cockroaches can pick up disease-causing bacteria, such as Salmonella, on their legs and later deposit them on foods and cause food infections or poisoning. House dust containing cockroach feces and body parts can trigger allergic reactions and asthma in certain individuals.
American cockroaches generally live in moist areas, but can survive in dry areas if they have access to water. They prefer warm temperatures around 29 °C (84 °F) and do not tolerate cold temperatures. In residential areas, these cockroaches live in basements and sewers, and may move outdoors into yards during warm weather. These cockroaches are common in basements, crawl spaces, cracks and crevices of porches, foundations, and walkways adjacent to buildings.
American cockroaches have three developmental stages: egg, nymph, and adult. Females produce an egg case (ootheca) which protrudes from the tip of the abdomen. On average, females produce 9–10 ootheecae, although they can sometimes produce as many as 90. Cockroach is paurometabolous. After about two days, the egg cases are placed on a surface in a safe location. Egg cases are about 0.9 centimetres (0.35 in) long, brown, and purse-shaped. Immature cockroaches emerge from egg cases in 6–8 weeks and require 6–12 months to mature. After hatching, the nymphs feed and undergo a series of 13 moultings (or ecdysis). Adult cockroaches can live up to an additional year, during which females produce an average of 150 young.
American cockroaches are omnivorous and opportunistic feeders that eat a great variety of materials such as cheese, beer, leather, bakery products, starch in book bindings, manuscripts, glue, hair, flakes of dried skin, dead animals, plant materials, soiled clothing, and glossy paper with starch sizing. It is particularly fond of fermenting foods. They have also been observed to feed upon dead or wounded cockroaches of their own or other species.
Due to their large size and slow development, large infestations of these insects are not common within houses. However, during certain times of the year, these cockroaches may move inside a house from outside. In cold weather these cockroaches may move indoors, seeking warmer temperatures and food. Cockroaches may enter houses through sewer connections, under doors, around plumbing, air ducts, or other openings in the foundation. Cockroach populations may be controlled through the use of insecticides. It is also wise to cover any cracks or crevices through which cockroaches may enter. Also, always clean any spills or messes that have been made so that the cockroaches will not be attracted to the food source. Another way to prevent an infestation of cockroaches is to thoroughly check any material that is brought inside. Cockroaches and egg cases can be hidden inside or on furniture, in boxes, suitcases, grocery bags, etc.
Comparison of three common cockroaches
|Roach||German cockroach||Oriental cockroach||American cockroach|
|Size||13–16 mm (0.51–0.63 in)||18–29 mm (0.71–1.14 in)||29–53 mm (1.1–2.1 in)|
|Preferred temperature||15–35 °C (59–95 °F)||20–30 °C (68–86 °F)||20–29 °C (68–84 °F)|
|Nymphal development[note 1]||54–215 days|
(at 24–35 °C (75–95 °F))
(at 22–30 °C (72–86 °F))
(at 25–30 °C (77–86 °F))
|Adult life span||Around 200 days||35–190 days||90–706 days|
|Able to fly?||Poorly[note 2]||No||Yes|
- Dependent on several factors, including temperature (significantly), gender, and nutrition.
- German cockroaches can glide, especially males, but powered flight is uncommon.
- Cassidy, Frederic Gomes; Hall, Joan Houston (2002). Dictionary of American Regional English (illustrated ed.). Harvard University Press. p. 20. ISBN 978-0-674-00884-7.
- Poertner, Bo (10 December 1997). "Palmetto Bug - Roach Or Beetle? Quit Debating, We Have The Answer". Orlando Sentinel. Retrieved 9 December 2013.
- Encyclopedia of Life. "Periplaneta americana - American Cockroach". Retrieved 2013-12-09.
- Bell, William J.; Adiyodi, K.G. (1981). American Cockroach. Springer. pp. 1, 4. ISBN 978-0-412-16140-7.
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- Barbara, Kathryn A. (2008). "American cockroach - Periplaneta americana (Linnaeus)". Retrieved 2008-07-10.
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- Merritt, Thomas M. (July 31, 1999). "Chapter 39 — Fastest Runner". Book of Insect Records. University of Florida.
- Shukolyukov, S.A. (September 27, 2001). "Discovering the Achievements of the American Cockroach". University Science News. Retrieved 2008-07-10.
- "Fastest Land Insect".
- Jacobs, Steve. "American Cockroaches". The Pennsylvania State University. Retrieved 18 October 2012.
- "Evaluation of the common cockroach Periplaneta americana (L.) as carrier of medically important bacteria". pubmed.gov.
- "New York City Environmental Health Services". Retrieved 2012-07-11.
- "American Cockroach". Amalgamated Pest Control.
- Jones, Susan C. (2008). "Agricultural and Natural Resources Fact Sheet: American Cockroach (HYG-2096-08)" (PDF). Ohio State University.
- Robinson, William H. (14 April 2005). Urban Insects and Arachnids: A Handbook of Urban Entomology. Cambridge University Press. pp. 45–46, 51–54. ISBN 978-0-521-81253-5.
- Bassett, W.H. (12 October 2012). Clay's Handbook of Environmental Health. Routledge. p. 317. ISBN 978-1-135-81033-7.
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