Why are There So Many Insects?
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Insects: The True Conquerors of the Planet
If insects were to suddenly morph into large beings and wage war on us, there is no doubt that humans would lose. We would be crushed by their sheer numbers. There are an estimated 10 quintillion individual insects on Earth, which is a one followed by 19 zeroes. This means that compared with our population of about 7 billion, these invertebrates outnumber us by more than a billion to one. There are more than 60,000 vertebrate species on the planet, but the class of insects contains a million known species, and many others that haven’t been classified. In fact, these critters make up approximately 75% of all animals on Earth.
The Secret to Their Success
So, what is the secret to their success? Insect abundance comes down to many things that together make them some of the most adaptable and resilient creatures. This includes their impressive ability to breed; many species can produce hundreds of offspring within their lifetimes. Offspring of insects mature rapidly, allowing the cycle of reproduction to occur over and over again in a short period of time. This contributes to the vast genetic diversity of insects as a class, providing them with the necessary adaptations to survive in a range of environments across the planet. This includes extreme environments such as -40 degrees Fahrenheit, or the Sahara Desert when surface temperatures exceed 155 degrees, as well as 18,000 feet above sea level. Insects also benefit from their exoskeletons, which act as body armor and protect them from the outside world, as well as their small size, which allows millions of insects to inhabit a small space and make use of all available resources.
Insects’ Niches and Ecosystems
Insects occupy hundreds of different niches across ecosystems. Some survive by eating the roots, stems, leaves, seeds, pollen, and nectar of specific plants. Others, like wasps, take advantage of live insects by paralyzing them and laying their eggs inside so that when the hatchlings emerge, they can eat their way out and get nourishment. Mosquitos and biting flies feed on blood, taking advantage of this unusual resource to ensure their survival. Additionally, a whole bunch of other insects have built a niche around feces. Flies lay their eggs there, and some beetles even build large balls out of animal dung, which they eat and use as accommodation for their eggs.
Mighty Power of Metamorphosis
The insects’ mighty power of metamorphosis not only transforms them but also helps them maximize the available resources in an ecosystem. For example, butterflies in their larval caterpillar form chomp hungrily through leaves at a rapid rate to help them grow and spin cocoons. When they emerge as butterflies, they feed on nectar from flowers, allowing them to migrate and spread pollen. Metamorphosis is an incredibly efficient process that allows 86% of insect species to successfully share an ecological niche without limiting their own success. It ensures that larvae and adults of one species will never compete for the same resource, such as flower nectar.
Conclusion
We may not always notice it, but insects are everywhere and their numbers are immense. Everywhere you look, you’re sure to find them. It’s clear that insects are the true conquerors of the planet, not us.
Discussion Questions
- What would the world be like without insects?
- What specific qualities enable insects to be so successful?
- What other animals survive in extreme temperatures and altitudes?
- What would happen if insects stopped consuming the resources they do?
- How do insects benefit from metamorphosis?
- What would happen if insects weren’t so genetically diverse?
- How can humans better coexist with insects?
- What will happen to insect populations in the future?
Lesson Vocabulary
Insects – Small invertebrate animals with six legs and a hard outer shell. – Example sentence: There were hundreds of insects buzzing around the flowers in the garden.
Metamorphosis – The process of transformational development of an organism. – Example sentence: The butterfly underwent a complete metamorphosis, transforming from a caterpillar to a beautiful butterfly.
Exoskeleton – An external skeleton found in some organisms, used to protect and support the body. – Example sentence: The crab had a hard exoskeleton that protected its delicate organs from predators.
Adaptable – Able to adjust to new conditions or fit different purposes. – Example sentence: Humans are highly adaptable and can survive in many different climates.
Resilient – Able to recover quickly from difficult situations. – Example sentence: John was resilient in the face of adversity and was able to quickly recover from his financial losses.
Breeding – The process of producing offspring by sexual reproduction. – Example sentence: The wolves have begun breeding and have produced several litters of pups.
Offspring – A creature that is the child or descendant of a particular parent. – Example sentence: The lioness had two offspring that she was training to be strong hunters.
Mature rapidly – To reach full size or full development quickly. – Example sentence: The baby rabbit matured rapidly and was fully grown by the age of three months.
Genetic diversity – The variety of genes in an organism or a population. – Example sentence: The species was saved from extinction due to the high level of genetic diversity among the population.
Extreme Environments – Habitats that are incredibly harsh or difficult to survive in. – Example sentence: Scientists discovered a species of bacteria living in extreme environments, such as boiling hot springs.
Niches – A specific function or role occupied by a species in its environment. – Example sentence: The vulture has an important niche in its ecosystem, as it helps to clean up dead animals.
Ecosystems – A biological community of interacting organisms and their physical environment. – Example sentence: The rainforest is a complex ecosystem that is home to millions of species of plants and animals.
Pollen – Tiny, dust-like grains which are produced by plants. – Example sentence: The bees were collecting pollen from the flowers in the garden.
Nectar – A sweet liquid that is produced by plants, and is an important source of food for many animals. – Example sentence: The hummingbird was sipping the nectar from the flowers in the meadow.
Conquerors – A person or group that gains control over a country or land by force. – Example sentence: The conquerors built a castle to help them protect their newly acquired land.
Resource – A source of material or energy that can be used to increase wealth. – Example sentence: Oil is a valuable resource that is used to produce many different products.
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- Categories: Nature of Science, TED Ed, Video Lessons
- Keywords: adaptable, breeding, conquerors, ecosystems, exoskeleton, extreme environments, genetic diversity, insects, mature rapidly, metamorphosis, nectar, niches, offspring, pollen, resilient, resource
