A nuclear war, if it comes, will not be won by the Americans … the Russians … the Chinese. The winner of World War III will be the cockroach.
— 1965 advertisement sponsored by the National Committee for a Sane Nuclear Policy
Cockroaches have an impressive win record. The Cretaceous-Paleogene extinction, which eliminated 80% of animal life, wasn’t enough for this arthropod. Neither were the other mass extinction events that culled countless animal and plant species from the Earth. Thundering through ancient forests, the Tyrannosaurs rex ultimately proved less resilient than the cockroaches that scurried underfoot.
The cockroach is known for having Rasputin-esque survivability, capable of withstanding anything from nuclear radiation to decapitation. Yet questions remain regarding how adaptable roaches really are. Will cockroaches really outlive humans? We’ll be answering that question as well as exploring the evolutionary traits that have helped this species endure so effectively.
Can Roaches Survive a Nuclear Blast?
The cockroach’s reputation for persistence developed after the bombing of Hiroshima and Nagasaki, when roaches were reportedly seen emerging from the rubble unscathed. The idea that roaches will outlive humans is built upon the notion that they are capable of surviving a nuclear blast. However, a cockroach would not survive the intense heat of a nuclear fireball or the crushing pressure of the resulting shockwave.
Exposing Roaches to Radiation, For Science
Can cockroaches survive a nuclear war and become the only lifeform on Earth? This question was addressed by the Discovery Channel’s MythBusters. In the interest of science, the MythBusters team exposed cockroaches, fruit flies and flour beetles to three levels of radiation. Flour beetles were the only insect capable of surviving a 100,000 rad (radiation absorbed dose), and the myth was declared busted. Cockroaches have low radiation tolerance when compared to other insects. However, they still managed to survive after being exposed to 10,000 rad, which is 10 times the lethal dose for humans. The world may be inherited by flour beetles, but cockroaches would still likely outlive humans after a radioactive fallout.
Insects like the cockroach are resistant to the damaging effects of radiation because of their slow cell division. The cells of a living organism are able to repair damage caused by radiation, but they are more susceptible to damage while in the process of dividing. Insects only go through cell division prior to molting, so unless a cockroach is ready to shed its exoskeleton, it’s unlikely to be heavily affected by radiation.
Survival of the Fittest
Humans may have been blessed with opposable thumbs, but roaches have several evolutionary advantages. According to George Beccaloni, zoologist and former curator at London’s Natural History Museum, “Cockroaches as a group are one of the most if not the most varied of all insect groups, in terms of their reproductive biology.” A few species are parthenogenetic, meaning that they reproduce asexually. Others produce egg sacks, and others have abandoned egg cases in favor of nurturing eggs in their brood pouch. Females of certain species literally take their offspring under their wing — their forewing, to be exact. With these diverse means of reproduction at their disposal, the cockroach is well equipped to rebound after a cataclysmic event.
A Sensitive Palate
An analysis of the genome of the American cockroach revealed widely expanded gene families associated with environmental adaptation, such as chemoreception (taste and smell) and detoxification, when compared with other insects. Researchers found that the roach has 522 gustatory (taste) receptors, which allow roaches in unsanitary environments to differentiate between safe and toxic food. Their detoxification system, moreover, includes enzymes capable of overcoming harmful compounds, including some found in insecticides.
Off With Their Heads
Due to their open circulatory systems, cockroaches can even survive decapitation. Remove their heads and blood clotting around the neck will form a seal. Breathing through spiracles, or respiratory openings throughout their bodies, headless roaches are capable of surviving weeks without food. They can even perform simple movements. (We’re not going to dwell on how scientists arrived at these findings.)
Nature’s Decomposers
Will cockroaches outlive humans? Undoubtedly. They may not be as resistant to radiation as once claimed, but roaches are hardy survivors capable of existing in extreme conditions. The cockroach species Eupolyphaga everestiana can even be found on the slopes of Mount Everest. Roaches have crawled, scurried and flown across the Earth for about 300 million years, and it stands to reason that they’ll continue to do so.
There are nearly 5,000 species of roaches, and only around 30 are known to be pests. Rarely venturing into households, these insects are a food source for a number of animals, including birds and rats. More importantly, they play an important role in the nitrogen cycle, feeding on dead and decaying matter and recycling nitrogen back into the soil. Entire ecosystems depend on decomposers like the cockroach.
Keeping Urban Pests in Check
The question of which species will remain standing post-nuclear fallout will, hopefully, remain unanswered. What’s known is that the qualities that make roaches a successful species also make them a difficult pest to control, especially their resistance to ingredients found in insecticides. By implementing integrated pest management (IPM) strategies, however, professionals in the field of entomology can prevent and exclude these pests in places where they have the most impact on human health and wellness.
The University of Florida offers an online entomology master’s degree and an online entomology graduate certificate, each with four specialization options, one of which is urban pest management. Courses like Principles of Urban Pest Management empower students with the knowledge needed to manage cockroaches and other urban pests, including blood-sucking insects and stored food pests. Apply to one of our online entomology programs to help ensure that insects like the cockroach wait their turn before inheriting the planet.
Sources:
https://www.livescience.com/33995-cockroaches.html
https://www.livescience.com/32749-could-cockroaches-really-survive-a-nuclear-winter.html
http://scienceline.ucsb.edu/getkey.php?key=1470
https://www.scientificamerican.com/article/fact-or-fiction-cockroach-can-live-without-head/
https://www.livescience.com/62093-why-cockroaches-can-survive-anything.html
