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AMAZING COCKROACH FACTS

Here are some exciting results of the research done on 'INDOOR COCKROACH INFESTATION IN SOME URBAN AND RURAL DWELLINGS OF THAILAND':

"Cockroach surveys using sticky traps were conducted in urban areas of 14 Thailand provinces. At least 30 houses in each province were randomly sampled for cockroaches. Each house was trapped in three areas:
kitchen, bedroom and outside. A total of 2,648 cockroaches was caught by 550 out of 1,542 traps (35.7%), from 337 of the 514 houses (65.6%). Overall, relative density ranged from 2.6 to 9.1 with an average of 5.2 cockroaches/house. On the average, 47.7% of the cockroaches were caught in the kitchen, 24.4% and 27.9% were caught in the bedroom and outside of dwellings, respectively."  Journal of Vector Ecology 26 (2): 2001.

Chiang Mai, with 6 species, had the highest number of cockroach species recorded.

 

Cockroaches have been present on the earth for more than 400 million years. Approximately 4000-7500 species of cockroaches exist, but only a very small fraction of these species are considered pests (i.e., American, German, Oriental, brown-banded, smokybrown, and Asian).
http://www.biohaven.com/pests/roach/roachinf.htm

The Madagascar hissing cockroach is a large, wingless cockroach from Madagascar. The aggressive encounters between males are quite impressive. Males ram into each other with their horns and/or they push each other with their abdomens. Larger males usually win. Hissing plays an important role during male-male inter- actions. Winners of encounters hiss more than losers. The hisses of males also contain information about the size of the male hissing and may be used to assess the opponent's size. Males can also discriminate among the hisses of familiar males and strangers. These hisses are audible and can be heard by observers. Although this species is primarily nocturnal, you can see males fighting during the day.

Males also hiss during courtship interactions with females. Again, their behavior is unusual for insects in that strength and sound are used. Mating occurs in an end-to-end position. To achieve this, the male pushes his abdomen under and along the female's body until he engages the end of her abdomen.

Although hissing plays an important role in colony hierachy and courtship interactions, it is the disturbance hisses that most people are familiar with. Adult males, adult females, and older nymphs hiss when disturbed or handled. This hiss is very loud and easily heard. This is the only type of hiss produced by females and nymphs.

While many insects use sound, the Madagascar hissing cockroach has a unique way of producing its hisses. In this insect, sound is produced by forcibly expelling air through a pair of modified abdominal spiracles. Spiracles are breathing pores which are part of the respiratory system of insects. Because the spiracles are involved in respiration, this method of sound production is more typical of the respiratory sound made by the vertebrates. In contrast, most other insects produce sound by rubbing body parts (e.g. crickets) or vibrating a membrane (e.g. cicadas).

by Debbie Clark and Donna Shanklin, Entomologists
University of Kentucky College of Agriculture
http://www.uky.edu/Agriculture/Entomology/entfacts/misc/ef014.htm


Cockroaches and "The Bomb"
You've probably heard the story about cockroaches surviving a nuclear war: we die but they live! This is supposed to make you feel better when you have trouble getting rid of these critters.
So, the real truth: radiologists have found that humans can safely withstand a one-time exposure of 5 rems (A "rem" is the dosage of radiation that will cause a specific, measured amount of injury to human tissue). A lethal dose is 800 rems or more (people are exposed to about 16 rems during their lifetime).

Insect researchers have found that cockroaches can tolerate a much higher dose -- really higher! The lethal dose for the American cockroach is 67,500 rems and for the German cockroach it is between 90,000 and 105,000 rems (yikes!). In truth the amount of radiation that cockroaches can withstand is equivalent to that of a thermonuclear explosion. So, show a little respect the next time your chasing one through the kitchen with a spray can in your hand!

Reprinted from the Urban Pest Control Research Center Newsletter, April 8, 1996. By Bill Robinson, Virginia Polytechnic Institute and State University, Department of Entomology

http://www.ent.iastate.edu/ipm/hortnews/1996/12-13-1996/bomb.html

a cockroach could live a long time, perhaps a month, without its head.

The world's largest roach (which lives in South America) is six inches long with a one-foot wingspan.

Roaches By the Numbers
6 -- Number of legs on a cockroach
18 -- Number of knees on most cockroaches (at least!)
40-- Number of minutes cockroaches can hold their breath
75 -- Percentage of time that cockroaches spend just resting (how lazy can you get?)
Bad News
Some female cockroaches mate once and are pregnant for the rest of their lives (bummer).
Better Check Those Cracks in the Wall
Young cockroaches need only a crack as thin as a dime (about .5mm wide) to crawl into. Adult males can squeeze into a space of 1.6mm or the thickness of a quarter.
Wanna Race?
Cockroaches can run up to three miles in an hour. (Hey, it's no marathon, but it's not bad.)
http://yucky.kids.discovery.com/noflash/roaches/pg000097.html
Yuck!
Male cockroaches transfer sperm to females in a "gift-wrapped" package called a spermatophore. Some males cover the package in a protein-rich wrapping that the female can eat to obtain nutrients to raise her young. Delicious!

The New Zealand Y2K Readiness Commission has given new meaning to the phrase 'millennium bug'. The commission employed Ken, a computer-generated cockroach, to urge New Zealanders to hoard essential supplies in case the world ended on New Year's Eve, 1999. In the event that you found yourself starving, however, the commission helpfully included the following 'succulent' cockroach recipe in its press kit.

Simmer cockroaches in vinegar. Then boil with butter, farina flour, pepper and salt to make a paste. Spread on buttered bread.

http://www.bbc.co.uk/h2g2/guide/A164648

The Blattodea or Cockroaches
In the introduction to his book "The Cockroach Vol.1" P.B.Cornwell's opening sentence is . "The Cockroach is probably the most obnoxious insect known to man." This is obviously the statement of a man who has spent too much time studying those few species of Blattodea which have so much in common with mankind that they have chosen to live with us.

There are nearly 4,000 species of Cockroaches (Dictyoptera, Blattodea) in the world, of which only 25 to 30 (or less than 1%) have any pest status, the rest are innocent members of the Earth's fauna, some of which are clean living, non-aggressive and slow moving, and as such make great pets. The largest known Cockroaches in the world are (largest wingspan up to 18 cm) Megaloblatta longipennis, largest body, Macropanesthia rhinocerus from Australia weighing in at up to 50 grams. The smallest known is Attaphilla fungicola which lives in the nests of Leaf Cutter ants of the genus Atta in North America and feeds on the fungus they farm, it is about 4 mm long
http://www.earthlife.net/insects/blatodea.html
Gordon's Blattodea Page

Cockroaches (Periplaneta americana) can really move. They can run at speeds of nearly 3km/hr (0.8 m/s). They can make up to 25 body turns in a second - the highest known rate in the animal kingdom. And, being nocturnal, they do most of this in the dark. So why don't they crash into things?

The answer is: their antennae. In a series of cockroach-assault course experiments J Camhi and E Johnson of The Hebrew University, Jerusalem, Israel have found that these much-loathed insects boast highly flexible and seriously sensitive antennae one and a third times the length of their bodies and segmented into between 150 and 170 jointed sections.

Camhi and Johnson set cockroaches (whose antenna and other sensory organs they disabled in various ways) the task of negotiating their way around a circular arena with either straight or pleated sides. As the duo report in The Journal of Experimental Biology, their slightly macabre manipulations revealed that the insects navigated the space by staying close to the wall at a strikingly fixed distance and dragging their antenna along it as they went.

At walking speed intact cockroaches simply tapped their antennae on the arena wall, but the faster an insect moved the more time the two stayed in contact. When the researches experimented with simple antenna amputations, they found that the shorter an insect's antenna, the closer it walked to the wall at all running speeds, apparently using sensory input from other body parts, such as its legs, to glean information about its position relative to possible obstacles. And experiments with the pleat-sided arena showed that cockroaches can respond remarkably quickly - after around 29 milliseconds - to the sensory cues that their antennae deliver.

Furthermore the researchers found that blinded and deafened cockroaches were able to navigate completely normally, even if their average speeds were lower than their sighted and air-current-sensitive counterparts.

http://www.nature.com/nsu/990211/990211-6.html

 

Nature Science update
Female cockroaches prefer males at the bottom of the social pecking order, and dominant males try and stop them from having their way. But when females do get the low-ranking man of their dreams, they produce fewer sons, apparently in an effort to avoid passing on his wimpishness

the laboratory cockroach, Nauphoeta cinerea. These animals usually reproduce sexually. But in times of crisis when males are scarce, females can reproduce by a process known as 'parthenogenesis'. They can produce offspring-all female-with no help from males.

"Cockroaches are considered one of the most successful groups of animals," says Steven Jacobs, senior extension associate in entomology in Penn State's College of Agricultural Sciences. "Because they are so adaptable, cockroaches have adjusted to living with humans much more readily than humans have adjusted to living with them."

Cockroaches thrive in nearly every corner of the globe, despite our best attempts to eliminate them.
Penn State Agricultural information services

Why is it almost impossible to squish a cockroach before it shoots out of sight behind the refrigerator while it is often quite easy to zap it with the nozzle of a vacuum cleaner?
The answer, Dr Hananel Davidowitz of the NEC Research Institute in Princeton, N.J., says, is that the jet-propelled bug thinks with its behind.
The cockroach, he says, is able to sense minute changes in the air flowing round its body using tiny hairs on two posterior appendages called “cerci”—and that includes your foot coming down. Signals from those hairs feed into a group of 14 vital nerve cells which process the information. The result—now you see it, now you don’t.

Confused by Vacuum
The vacuum cleaner, however, has even smart roaches fooled.
“If a vacuum cleaner approaches from behind a cockroach, the wind goes from its head to the nozzle. It thinks the attack is from the front and it turns round and runs straight into the nozzle,” the scientist says.
Cockroaches have also developed interesting ways of ensuring that their young make it to adulthood. Most species give birth to live young — highly unusual for insects — but a sure way to prevent other critters from feeding on their eggs.
And if food is scarce, adolescent cockroaches can live on a very reliable resource — their parents’ feces.
The Madagascar cockroach can reach the ripe old age of seven and produces less than 20 eggs during that long life span.
abc news

In the natural world, dodging disaster is vital if you are not going to be pounced on by predators. Now, the world champion dodger has been crowned - the cockroach
BBC

Other scientists in Europe and America have also connected neurons to microchip circuitry and a team in Japan has been able to stimulate the muscles in a cockroach leg with electrical signals so that its movements can be controlled.

There could be big advantages for the military. Rats could be used to check damage at bombed enemy factory sites, where their presence would be unlikely to raise suspicion. Dogs could be used to search for casualties on battlefields and cockroaches could be used to place surveillance devices in military installations
The London Times

SCOUTING FOR SURVIVORS. Insect legs, by contrast, are designed for scurrying over rocky or uneven surfaces. To that end, University of Michigan researchers studied cockroaches, which any urban dweller knows can move with astonishing speed. The result is RHex, a six-leg robot that runs over rubble with ease, not to mention leaping obstacles and climbing stairs. RHex could be used in search-and-rescue operations, either to scout for survivors amid the rubble of disaster zones like the World Trade Center site or to bring back information from places where humans fear to tread.
BW Online
Among the more futuristic scenarios portrayed in the study, robots called neural network bugs, built like small cockroaches, can crawl to the best location for surveillance. Researchers are now working on controlling and manipulating real cockroaches by implanting microprocessors and electrodes in their bodies. "The insects can be fitted with micro-cameras and sensors to reach the places other bugs can't reach," Wright says
EUROBYTES

Scientists claim some female cockroaches prefer weaker partners because they like gentle sex.
A University of Manchester team has concluded stronger male cockroaches are too aggressive and often injure
their partners. However, the females produce fewer babies with weaker partners. The scientists studied the sex life of the Tanzanian cockroach Nauphoeta cinerea and have published their results in the science journal Nature.
Elisabet Forsgren, a behavioural ecologist at G?teborg University in Sweden, commented: "People have taken it
for granted that females should prefer dominant males. "But there are about a dozen species, from moths to birds to salamanders, where this has been shown not to be the case."

 

THE INDOOR COCKROACH INFESTATION IN SOME URBAN AND RURAL
DWELLINGS OF THAILAND (NO. 044)
Duangporn Nacapunchai, Patchara Sriwichai, Uraiwan Krainara, Anitaya Chanthawee
Department of Parasitology, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand.

Cockroach allergy and exposure have been reported in asthmatic children, allergic conjunctivitis and slum people in Bangkok with parennial nasal symptom and wheezing which the prevalence is increasing . This study was aimed to investigate the infestation of indoor cockroach species in some urban and rural dwellings of Thailand. Cockroaches were caught by placing commercial sticky traps for three days. They were from 33 living rooms and 38 bedrooms of 36 houses and 33 office units in Bangkok. The dominant species of urban indoor cockroaches were Periplaneta americana and Supella longipalpa which the nymphal stage was the highest. In Bangkok, houses were infested with P. americana 81.7% and S. longipalpa 18.3% where P. americana were significantly higher in living rooms than bedrooms. In contrast, offices were infested with P. americana 52.3% and S. longipalpa 47% where S. longipalpa were significantly higher than those on houses. The average cockroaches per trap from office(14.5) were higher than home (3) The monthly variation were studied in single cockroach species of the infested areas. By this trapping, the density S. longipalpa was peaked on the second month and markly declined later to reach the zero within ten months but no variation for american cockroaches. From rural dwellings of 12 provinces, five species of cockroaches were found which were P. americana, Periplaneta australasiae, Blattella germanica, Neostylopyga rhombifolia, and S. longipalpa. The most common is P. Americana and the highest density was found in kitchen.
Faculty of Medical Technology U Mahidol

Abstract: Cockroach surveys using sticky traps were conducted in urban areas of 14 Thailand provinces. At least
30 houses in each province were randomly sampled for cockroaches. Each house was trapped in three areas:
kitchen, bedroom and outside. A total of 2,648 cockroaches was caught by 550 out of 1,542 traps (35.7%), from
337 of the 514 houses (65.6%). Overall, relative density ranged from 2.6 to 9.1 with an average of 5.2 cockroaches/house. On the average, 47.7% of the cockroaches were caught in the kitchen, 24.4% and 27.9% were caught in the bedroom and outside of dwellings, respectively. There were 10 species of cockroaches caught from the 14 provinces:
Periplaneta americana (60.9%), Periplaneta brunnea (15.4%), Neostylopyga rhombiofolia (9.6%), Periplaneta
australasiae (9.2%), Pycnoscelis surinamensis (3.3%), Blatella germanica (0.6%), Periplaneta fuliginosa (0.5%),
Supella longipalpa (0.3%), Blatella lituricollis (0.15%) and Nauphoeta cinerea (0.05%), belonging to six genera.
According to the surveys in this study, Periplaneta americana and Periplaneta brunnea were the most abundant
cockroach species in urban Thailand, whereas the kitchen was the major habitat. Journal of Vector Ecology 26
(2): 2001.