Four species of cockroaches found in Singapore, Environment News & Top Stories — The Straits Times

Four species of cockroaches found in Singapore

The Panesthia angustipennis. It can be found in Singapore’s forests. ST PHOTO: ALPHONSUS CHERN

German cockroach (Blattella germanica)


Measuring just about 1cm in length, German cockroches are one of three cockroach species considered pests in Singapore.

Unlike the Australian and American cockroaches, they do not fly. But they are carried by human transportation systems and adapt well to urban environments.

Ironically, clean, modern transporation systems have made it easier for German cockroaches to be carried around as there are fewer rats — its natural predator — around.

Australian cockroach (Periplaneta australasiae)


The Australian cockroach is about twice the size of the German cockroach, with a length of between 2 and 3cm. The Australian cockroach looks similar to the American cockroach, just slightly smaller and with yellow streaks by the sides of its body.

Panesthia angustipennis


This cockroach can be found in Singapore’s forests, where it helps to break down organic matter such as dead leaves.

This process is important as it means some of the nutrients in them are released back into the soil, where they can be used by other living things such as trees.

This cockroach speeds up this process of nutrient cycling, as the breakdown of dead matter by fungi and bacteria is much slower.

Madagascar cockroach (Gromphadorhina portentosa)


Measuring up to 7.5cm long, this cockroach is not considered a pest and is sometimes even kept as a pet. Its exoskeleton has an iridescent sheen, and this insect is known to hiss — as part of its mating ritual, or during fights.

A Guide to Identifying Common Types of Cockroach Species

Long despised by homeowners, the cockroach is more than just a creepy nuisance pest that can survive freezing temperatures and a week without its head. This hearty creature can pose serious health risks to humans if it finds a way indoors. In fact, all types of cockroaches pick up germs on the spines of their legs as they crawl through decaying matter, which may be transferred to humans through food contamination. This can lead to illnesses such as E. coli and Salmonella.

In addition, cockroaches are linked to increased asthma and allergy attacks as their droppings, saliva and shed skin contain potent allergens known to trigger allergic reactions and exacerbate asthma symptoms, especially in children.

To remain safe and healthy from different types of cockroaches, pest control and management is key. However, with approximately 4,000 living species of cockroaches in the world, and about 70 species found in the United States, it’s inevitable that some cockroaches will find a way inside homes. As a result, it’s important to pay close attention for signs of an infestation and take action if this pest is found. You should contact a licensed pest professional to properly identify the species and recommend a course of treatment, but you can also use this guide to help determine which type of cockroach has become an unwelcome houseguest:

Types of Cockroaches

American Cockroach

  • Appearance: American cockroaches are reddish brown with a yellowish figure 8 pattern on the back of their head.
  • Region: This species is located throughout United States.
  • Habitat: American cockroaches are often found in sewers and basements, particularly around pipes and drains.
  • Unique Facts: The American cockroach is the largest of the house-infesting cockroaches. They are active when the temperature is 70 degrees or higher, but they can survive lower temperatures with the right conditions.

Brownbanded Cockroach

  • Appearance: Brownbanded cockroaches are brown with pronounced banding across their wings.
  • Region: This species is found throughout United States.
  • Habitat: Within a room, brownbanded cockroaches tend to prefer warmer, drier, and higher locations than any of the other urban pest roaches. They are often found in upper cabinets or in rooms other than the kitchens or bathrooms. This species often hides its egg cases in or under furniture.
  • Unique Facts: Brown-banded cockroaches get their name from the two lighter bands they have across their dark brownish bodies. The male’s wings are larger than the female’s wings.
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German Cockroach

  • Appearance: German cockroaches are light brown to tan with two dark stripes located on their backs. They are oval shaped with six legs and antennae.
  • Region: This species is located across the United States.
  • Habitat: German cockroaches can be found throughout structures but show a preference for warm and humid places. They are usually found in kitchens and secondarily in bathrooms, but infestations often occur in rooms where people eat and drink.
  • Unique Facts: The German cockroach is by far the most important and usually the most common of the cockroaches. In addition to being a nuisance, the German cockroach has been implicated in outbreaks of illness and allergic reactions in many people.

Oriental Cockroach

  • Appearance: Oriental Cockroaches are large very dark colored and shiny.
  • Region: This species is found in the northern region of the United States.
  • Habitat: Oriental cockroaches are often found in sewers and will enter structures through drains. They find indoor harborage in basements and crawl spaces. They can also be found in leaf piles and firewood outdoors.
  • Unique Facts: Oriental cockroaches are sometimes called «water bugs» because they come out of drains, and «black beetle cockroaches» because of their smooth, dark bodies. This species creates a strong smell and is considered one of the dirtiest of all the cockroaches.

Wondering how to get rid of cockroaches? The best advice for cockroach control is to practice good sanitation. Homeowners should also seal any cracks or crevices on the outside of the home and eliminate moisture buildup in basements, attics and crawlspaces. When inspecting for types of cockroaches, pay extra attention to kitchens and bathrooms — especially under appliances and sinks — as these areas are particularly vulnerable to cockroach infestations.

Can Pests Transmit Coronavirus?

Now that winter has passed, it’s important to note that coronavirus is not spread by vector pests.

Here’s Why Cockroaches Can Survive Just About Anything

The genome of the American cockroach has been sequenced for the first time, revealing why these creepy-crawlies are such tenacious survivors.

The roach (Periplaneta americana) has widely expanded gene families related to taste and smell, to detoxification and to immunity, compared with other insects, according to a new study published March 20 in the journal Nature Communications.

«It makes total sense in the context of the lifestyle,» said Coby Schal, an entomologist at North Carolina State University who was part of a team that last month reported an analysis of the genome of the German cockroach (Blattella germanica). Many of the gene families that expanded in the American cockroach were also expanded in the German cockroach, Schal said. That makes sense because both species are omnivorous scavengers that can thrive on rotting food in seriously unsanitary environments.

Discriminating tasters

The American cockroach is a denizen of the sewers. It originally hails from Africa, but was introduced to the Americas in the 1500s. Unlike the German cockroach, which is a major pest found almost exclusively in human dwellings, the American cockroach mostly ventures only into the basements or bottom levels of buildings, Schal said. [Photos: Insects and Spiders That May Share Your Home]

Both roaches, though, are hardy survivors, and their genes hold the keys as to why. In the new study, researcher Sheng Li of South China Normal University and colleagues found that American cockroaches have the second-largest genome of any insect ever sequenced, right behind the migratory locust (Locusta migratoria), though a good 60 percent of the roach genome is made up of repetitive segments. Gene families related to taste and smell were much larger than those of other insects, and the researchers found 522 gustatory, or taste, receptors in the roach. German cockroaches are similarly well-equipped, Schal said, with 545 taste receptors.

«They need very elaborate smell and taste systems in order to avoid eating toxic stuff,» Schal said.

Hardy survivors

American cockroaches also had a larger-than-average suite of genes devoted to metabolizing nasty substances, including some of the ingredients in insecticides. German cockroaches have similar adaptations, Schal said. Both species developed these genetic changes long before humans came on the scene, he said. Thanks to their tendency to live among toxin-producing bacteria and to eat plant matter that might hold toxic substances, roaches were «pre-adapted» to the insecticides that humans throw at them, Schal said.

The American cockroach also had an expanded family of immunity genes, likely another adaptation for surviving unsanitary environments and fermenting food sources, Li and colleagues wrote. Finally, the roach had a large number of genes devoted to development, like genes responsible for synthesizing the insect’s juvenile hormone or the proteins in its exoskeleton. This made sense, the researchers wrote, since American cockroaches can grow up to 2 inches (53 millimeters) long and molt many times to reach that size.

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A greater understanding of the cockroach genome could help researchers come up with new ways to control pest species, the researchers wrote. One example, Schal said, is the Asian cockroach (Blattella asahinai), a close relative of the pesky German cockroach that lives outdoors and doesn’t bother humans much at all. It would be interesting to see if there are any differences between the Asian and German cockroach genomes that might explain why one is dependent on human-made environments and the other is not, Schal said.

Forest cockroach: lifestyle and related species of insect

The Journal is a forum for publication of studies of insects and related Arthropod groups on orientation, migration, social behavior, sexual selection, rhythmicity, mate finding and courtship, learning, predation, defense, and host finding. The Journal publishes original research and interpretative reviews.

To be considered for publication, original papers should emphasize behavioral reactions, not the endpoints of behavior. Laboratory choice bioassays should attempt to mimic field conditions as much as feasible and the assay’s duration should be comparable to the natural times for response. Often parallel, no-choice bioassays will be useful comparisons. Papers that identify behaviorally active compounds generally are appropriate for journals that emphasize chemical ecology. If new structures are proposed, however, the guidelines in the Journal of Chemical Ecology for structural verification are to be followed. Papers that focus on field trapping, simple feeding assays, or insect management are not appropriate unless there is a significant emphasis on behavior. The Journal does not publish papers describing the behavioral effects of botanicals or anthropogenic compounds such as pesticides, repellants, or environmental contaminants. Preliminary work is not publishable. Papers that are not in acceptable English will be returned without review. Authors who are non-native English speakers are encouraged to have their papers reviewed by a native speaker or use an editorial service before submission. Spelling and punctuation are to follow American usage. In the References section, authors should follow the format found in the Journal and not provide DOIs.

The order and family of the study organism are to be given in parentheses at their first mention in the Abstract and Introduction. Species’ authors are not to be given. Keywords should include the scientific name and family of the main study organism(s) if they are not mentioned in the Title. Authors are encouraged to deposit voucher specimens of the subject species in a recognized collection and if appropriate indicate the authority responsible for species identification; these should be mentioned in the Materials and Methods or Acknowledgments as appropriate.

  • Covers all facets of behavior of insects and other terrestrial arthropods
  • Presents peer-reviewed research and reviews
  • Internationally renowned editorial board
  • Range of topics includes behavioral ecology, motor patterns and recognition, and genetic determinants

Wood Cockroach


SIZE: An adult wood roach measures between three-quarters and 1.25 inches in length.

COLOR: The wood cockroach is chestnut brown with a flat, oval-shaped body, long antennae and spiny legs.

BEHAVIOR: Sometimes called “accidental invaders,” wood cockroaches live outside but wander into or get carried inside homes. They are often confused with German, American or Smoky Brown cockroaches. The males appear tan because of the color of their wings. The females are wingless and rarely seen. Both males and females have a translucent stripe on the outside edge of their thorax and the outside edge of their wings.

This roach looks somewhat like the common German cockroach, though the degree of similarity depends on the species as their appearance varies. Examining their behavior is the best way to tell the difference between the wood roach and the household roach. Wood cockroaches aren’t sensitive to light, so you can see them day or night. They aren’t skittish and are less likely to scurry away when you approach. Additionally, they will wander around your house without gathering in any particular area.


Native to North America, wood roaches live outdoors in moist woodland areas, including woodpiles, mulch, under the loose bark of trees, branches or decaying logs. These roaches need an environment that is consistently moist, so they don’t survive long nor breed indoors. The female wood roach uses this outdoor environment to her advantage, depositing egg capsules behind the loose bark of dead trees, fallen logs or stumps, safe from the prying eyes of hungry predators.

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These particular roaches aren’t prone to infest houses like other cockroaches, but you may see them inside your home occasionally. They could find their way in via a bundle of firewood. The males are drawn to lights at night, so they may crawl into your home through a window frame or other opening. When they are indoors, it’s a temporary situation, typically a few weeks in the spring.

The wood cockroach eats decaying organic matter such as rotting trees and leaf litter. They don’t eat your home’s structure or furniture. They are merely a nuisance should they find their way into your house.

Tips for Control

Because these roaches don’t breed inside the home, you seldom need to treat your home’s interior. The pesticides that control household roaches aren’t as effective against these types of roaches anyway. To get rid of wood roaches that have wandered inside your home, pick them up with a vacuum cleaner or broom and dustpan and discard them.

Your best approach is to take steps to keep wood cockroaches out of your house:

Don’t bring firewood inside until you’re ready to burn it.

Keep woodpiles away from your house and off the ground.

Seal cracks and small openings so they can’t slip inside.

Keep screens and weather-stripping around windows and doors in good repair.

Close your blinds or turn off lights at night so you don’t attract the males.

Limit using your porch light during mating season in late May and June when the males are often in flight.

If you live near a wooded area and wood roaches frequently enter your home, contact a Terminix® specialist to help determine the most effective treatment options for the exterior of your home.

The Best Plan for Ridding Your Home of Roaches (VIDEOS)

Oriental Cockroach (Blatta orientalis)

Detailing the physical features, habits, territorial reach and other identifying qualities of the Oriental Cockroach.

An affinity for moisture helps direct the infamous Oriental Cockroach into human habitats.

Found in all three countries of North America, the Oriental Cockroach is not originally from the continent. Despite the common name, it may not even originally come from Asia either. Regardless of its origin, it has established itself as one of a handful of pest cockroach species. Its ordinary habitat is woodland leaf litter and other moist areas, but its innate attraction to water and moisture has led the species to more developed areas. Because of its affinity for wet terrain, it is also called a Waterbug. Populations of Oriental Cockroaches commonly infiltrate sewer systems and pipelines, crawling on pipes and entering homes, offices, and other buildings through small openings, like those around pipes. They seek shelter in crawlspaces, cellars, and basements where high humidity is often normal. Once inside, they explore for food sources and sometimes hide in sink and tub drain holes. Their sudden emergence from drains terrifies the best of us. They tolerate dry areas well enough to also hide under furniture, behind radiators, and in dark closets. This adaptability makes them a serious nuisance indoors. This is also the type of cockroach seen scurrying out from under outside containers, like garbage cans.

The average lifespan of an Oriental Cockroach is about 18 months. They mature the first year, molting many times until they become winged adults. Long-winged males and the short-winged females cannot actually fly though. After mating, dark, tubular egg sacs the size of Tic-Tacs called ootheca are wedged in cracks, crevices, and other hiding places to increase the chances of offspring survival. Each brown capsule can carry over a dozen tiny eggs. Both nymphs and adults feed on pretty much anything, even filth and sewage, but they are especially fond of starchy items like crumbs, cereal, cookies, and most foods stored in pantries or cupboards.

Infestations are difficult to control and may require multiple treatments, possibly from a professional. Finding and destroying egg capsules in tiny cracks is hard, even with spray insecticide, so it is reasonable to think complete eradication from a home or building may require months of applications to reduce the living adult population and then the younger, newly born nymphs. There are some things one can do to make it harder for Oriental Cockroaches to enter a building in the first place: seal gaps in door and window trim, as well as gaps around any incoming pipes. Use an appropriate insecticide to spray around the exterior and interior of the building. Fix water leaks, even small ones, to help keep areas dry and less attractive.

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