Counting the World s Insects, HowStuffWorks

How many insects are there on Earth?

Counting the World’s Insects

The scientists who conducted the experiment described on the last page didn’t attempt to collect a sample of every insect species on Earth, but they were able to get a better grasp on the amount of diversity that exists across two separate U.S. regions. And that bumper? It yielded samples from 711 and 1,516 members of the Insecta class in the two regions tested.

Globally, scientists have identified about 925,000 species of insects, says Hogg, the entomology professor. Estimates on the number of total insects species fall as high as 30 million and as low as 2 million. The estimate that many people agree upon is about 5 million, so biologists have yet to identify more than 80 percent of the estimated total number of species. You can see the complications and uncertainty involved in assigning a number for the total of individual insects out there.

So if you were an entomologist determined to make your mark in the field, a better bet might be to discover a new insect species or two. Where might you look (and be prone to swatting a lot away as you search)? The tropics are the world’s most populous places in terms of insects, and tropical environments near the equator are also most conducive to plant and animal diversity. Ants are probably Earth’s most abundant insect species, says Hogg. In fact, in the tropics, the total biomass (weight) of ants is greater than that of all of the mammals combined.

The United States has insects in great abundance, too. Hogg’s research on aphids, an insect species that feeds on soybeans, took him to the Midwest. According to Hogg, in the peak of summer, one soybean plant can house up to 2,000 aphids. One acre can support up to 20,000 soybean plants, and in the upper Midwest, there are close to 40 million acres of soybeans. In other words, that’s a lot of aphids — 1.6 x 10 15 . But that’s just aphids. You came here to learn how many insects there are on Earth, so we’re not going to send you away disappointed.

The estimated number of individual insects currently hopping, crawling or flying around our planet at any given moment is about 10 quintillion, or the number «10» followed by 18 zeros, according to entomologist Dr. E.O. Wilson. That means there are about 2 billion insects for every human being, and assuming that there are 5 million species of insects, that means that each species has about 50 trillion individuals. So the next time you feel outnumbered, just remember: Unless you’re an insect, so is everyone else.

Scientists at New Mexico State University have developed an automated insect counter, with which one man in the field can obtain a year’s worth of data using a handheld device that links to a computer and populates a spreadsheet. But that’s just one method. There really isn’t a perfect way to count the vast multitudes of insects living above, below and on Earth’s surface yet.

animals.howstuffworks.com

List of edible insects of the world (April 1, 2017)

The list has been compiled by Mr. Yde Jongema, taxonomist at the Department of Entomology of Wageningen University & Research, the Netherlands.

To suggest changes in the list or additions please contact Mr. Jongema.

Changes or additions will only be made when supported by (if possible refereed) publications.

The list is alphabetically ordered subsequently at the following levels:

  1. Bio Geographical Region
  2. Order
  3. Family
  4. Genus
  5. Species

Comments on the list of edible insects of the world:

Biogeographical regions are adapted in general from M.D.F. Udvardy (1975), a classification of the bio geographical provinces of the world.

Afr Tropical Africa
AU Australian
Neotrop Neotropical
Or Oriental
Nearctic Nearctic
Pal Palaearctic

Mexico is added to the Neotropical region and China to the Palaearctic region, although the northern mountains of Mexico are Nearctic, and most of southern China is Oriental.

Other comments

  • The names of species marked with “check” are mostly not valid, but this needs to be checked further.
  • M” is an insect eaten for medical purposes.
  • Groups as termites and stingless bees are the most problematic in getting the right species names.
  • Author name in brackets means that the original description of the species was published under a different genus name.
  • Frequent used synonyms (syn) are mentioned in the first columns of the list.
  • Hepialidae from China should be treated with care, because of recent changes.

www.wur.nl

How many insects are there on Earth?

Whether you’re talking about a swarm of bees buzzing about, a cluster of butterflies sucking down nectar or a nest of cockroaches hidden in a corner of your house, insects are plentiful. Really plentiful.

Scientifically speaking, the term «insect» denotes a member of the class Insecta. For brevity’s sake, if you have a head, a thorax, an abdomen, three sets of legs protruding from your body and often a pair or two of wings, perhaps for making a quick getaway, then you’re most likely an insect. So how many are there?

It seems like an impossible question for good reason: We don’t even know how many different insect species there are, which makes it difficult to perform an all-inclusive worldwide insect census, according to David Hogg, an entomology professor at University of Wisconsin-Madison specializing in population ecology and pest management.

See also:  How to Overcome Your Fear of Ticks and Lyme and Get Outside Again

Add to that monumental task the often brief life span of an insect, such as the adult mayfly — a mere 24 hours — and you’d have some serious difficulty physically counting all the insects filling the planet’s air at any given moment [source: Turpin]. If you were really interested in this endeavor, you might have more luck counting insect queens of the ant, termite and bee varieties, which may rule their colonies for years. In fact, a termite queen may reign for as long as half a century [source: Turpin].

Of course, entomologists are interested in more than just the ruling class of the insect world, so they’ve devised automated and old-fashioned ways to survey, count and classify insects present in a select area.

One novel technique for measuring biodiversity may surprise you: A group of scientists sought to find out how many different species of insects inhabited two different regions. To collect the raw data, they used the front bumper of a moving vehicle and the open road. The resulting bug splatter on the bumper contained a treasure trove of genetic evidence from the various insects that struck it. The scientists then sequenced the DNA samples from the splatter and compared it with existing sequence databases for insects.

The method isn’t perfect, but it does attempt to classify, if not quantify, those buzzing masses.

animals.howstuffworks.com

Number of Species Identified on Earth

How many species known to currently exist in the world.

Category Species Totals
Vertebrate Animals
Mammals 5,513
Birds 10,425
Reptiles 10,038
Amphibians 7,302
Fishes 32,900
Total Vertebrates 66,178
Invertebrate Animals
Insects 1,000,000
Spiders and scorpions 102,248
Molluscs 85,000
Crustaceans 47,000
Corals 2,175
Others 68,827
Total Invertebrates 1,305,250
Plants
Flowering plants (angiosperms) 268,000
Conifers (gymnosperms) 1,052
Ferns and horsetails 12,000
Mosses 16,236
Red and green algae 10,386
Total Plants 307,674
Others
Lichens 17,000
Mushrooms 31,496
Brown algae 3,127
Total Others 51,623
TOTAL SPECIES 1,730,725

The species totals do not include domestic animals such as sheep, goats and camels. Nor do they include single-celled organisms such as bacteria.

Reference

The World Conservation Union. 2014. IUCN Red List of Threatened Species 2014.3. Summary Statistics for Globally Threatened Species. Table 1: Numbers of threatened species by major groups of organisms (1996-2014).

www.currentresults.com

The Bugs Of The World Could Squish Us All

And we’d deserve it.

The questions that kids ask about science aren’t always easy to answer. Sometimes, their little brains can lead to big places that adults forget to explore. That is what inspired our seriesScience Question From A Toddler, which uses kids’ curiosity as a jumping-off point to investigate the scientific wonders that adults don’t even think to ask about. The answers are for adults, but they wouldn’t be possible without the wonder that only a child can bring. I want the toddlers in your life to be a part of it! Send me their science questions, and they may serve as the inspiration for a column. And now, our toddler …

Q: What weighs more: all of the people or all of the bugs? — Carson S., age 4

This answerWe continue to have … complications … since we often come back to these children almost a year after they first submitted their questions. Last time, our toddler didn’t even remember asking the question — or care about the response. This time, young Carson slipped in an extra layer to his original question, asking about the weight of all the animals (presumably just the non-bug ones?) as well. We have strategically chosen to ignore this burst of youthful curiosity because we had already written the article and, as everyone knows, no backsies.

«> 1 is maybe best illustrated by two unrelated studies whose authors probably never guessed they’d be used together. In 2012, scientists estimated the global human biomass (i.e., how much we all weigh) at 287 million metric tons.This estimate was based on population levels from 2005. It’s probably a little higher now.

«> 2 Five years later, a different group of scientists set out to estimate how much the world’s spiders were eating. They came up with a horrifying (if somewhat inexact) estimate of 400 million to 800 million metric tons’ worth of prey each year. In other words, just the subset of bugs eaten by spiders last year probably outweighs all the humans on Earth. Even if the humans are, generally speaking, a touch better off in the end.

So all of the bugs definitely weigh more than all of the humans. But as you hug your knees and gently rock, trying not to touch any of the filthy, bug-covered surfaces that surround you at all times, you should know that this apparent win for bugkind masks some serious problems for the bugs and, as a result, for us. Turns out, there are fewer bugs than there used to be — both in total weight and in terms of species diversity. And we humans are to blame.

But first, let’s back up a minute and talk a bit about why it’s possible for bugs to outweigh humans. The sheer number of bugs in the world is a little difficult to fathom. “There’s an estimated 10 quintillion insects on the globe,” said Julie Peterson, professor of entomology at the University of Nebraska-Lincoln. “That’s 10 with 18 zeros after it, and that’s just insects. That’s not counting other arthropods like spiders and mites.” Insects — along with ticks, centipedes, spiders and all the other land-dwelling creepy-crawlies that we colloquially call “bugs” — probably represent as much as 80 percent of the species on this planet. In contrast, humans are a single species, made up of (as of this writing) 7,386,922,190 individuals.

To make those enormous numbers easier to grasp, let’s turn to an anecdote: Elizabeth Borer, a biology professor at the University of Minnesota, told me about a 1982 study in which an entomologist named Terry Erwin went to Panama and started taking samples of the beetles he found in one type of local tree. To do this, researchers fog a tree with pesticide the way an exterminator might fog a house, and then they count and categorize the unfortunate bugs that fall out. Erwin found more than 955 species of beetles in just 19 trees. Not 955 individual beetles. Species. Based on what he knew about the prevalence of this type of tree in the Panamanian forest and the prevalence of beetles compared to other kinds of insects, Erwin came up with a back-of-the-envelope calculation that every hectare of Panamanian forest could be home to as many as 41,000 species of insects — millions, maybe hundreds of millions, of individuals living in an area not much larger than a couple of soccer fields.One hectare is equal to a little less than 2.5 acres, and an acre is about the size of a soccer field.

And this is why bugs, as a whole, beat humans in a pound-for-pound weigh-off. Individual bugs may be small — the largest species, such as New Zealand’s grasshopper-like giant weta, top out around 70 grams, Peterson said — that’s about the size of a jumbo chicken egg. But even if you take what Peterson thinks is likely an underestimate of the average bug size — 0.05 milligrams, say — it still adds up by the time you multiply it by 10,000,000,000,000,000,000. This is a numbers game, and the bugs are very much ahead.

Granted, all of these numbers come from extrapolation and estimation. Scientists frequently do studies like Erwin’s, going to a region and taking samples that tell them how many bugs live in a tree, or on one square meter of ground. Take enough samples like that, and you start to get an idea of what’s normal for a particular kind of ecosystem. Then it’s just a matter of figuring out how much of that ecosystem covers the Earth and doing the math, Peterson said. The estimates also assume that there are a lot of insect species we don’t yet know about. One million species of insects have been named and documented, their type specimens sealed in jars or illustrated in books. There may be more than 4 million species yet to be catalogued.

And if all of that isn’t blowing your mind, consider what those quintillion bugs mean to the world. For starters, they’re an important part of the food chain — bird health, in particular, depends on bug health. Bugs are also pollinators, and that’s not just bees. Wasps, ants, flies and beetles all get in on that hot plant reproductive system action. And while not all the food we eat relies on pollinators, some of the really good stuff — almonds, avocados, many fruits and nuts, and the alfalfa that feeds our meat animals — does. Then there’s the role bugs play in decomposition. Dung beetles save the U.S. cattle industry $380 million every year by breaking cow poop down into dirt, a service that also helps to put nitrogen — an important source of plant food — back into the soil.

Bugs matter, and if scientists know how many bugs are in a square meter or what those bugs weigh, they can get an idea of how capable the existing bug population is of doing all the jobs bugs do. This is what scientists mean when they talk about “biomass.” If you know how much material a single dung beetle is responsible for decomposing, then knowing how many dung beetles there are helps you understand how much can be decomposed. If you know how many pounds of bugs a single bird eats, then you know how many birds can live off the bugs in a Panamanian tree. And the answers to those questions are pretty important, because they tell you practical facts — like whether birds can survive in a given habitat, or whether the poop is going to start piling up on your farm.

That means biomass is both a measure of the health of an insect community and of nature as a whole. And this is where the wacky science of weighing bugs starts to overlap with the existentially stressful science of watching helplessly as ecosystems collapse. Invertebrates, a group that includes insects, are poorly studied by conservation biologists, at least in comparison to their numbers, and the health of their communities can vary a lot by location and species. But the research that does exist suggests that insects aren’t doing well. For instance, the International Union for the Conservation of Nature (the group whose research plays a big role in determining which species we consider endangered) tracks only 3,623 species of terrestrial invertebrates — bugs, basically, plus worms and some mollusks. But of those, 42 percent are threatened with extinction. “We’re probably losing species faster than we can give them names,” Peterson said.

And you can see this in specific groups of species, as well. A 2015 study took advantage of a long history of records documenting populations of moths and butterflies in a protected grassland in Germany. It found declines in the number of species recorded, from a high of 123 in the 1870s to 71 by the early 2010s. What’s more, habitat-specific species were more likely to have been lost. In the 1870s, 50 percent of the moth and butterfly species were generalists: animals that can happily live in many places. By the 2010s, 68 percent were generalists. The species that were particular to those German grasslands faded faster. Peterson said that this pattern is reflected in many other places. Resilient generalists survive, while the species that can’t adapt as easily flounder. And that’s bad for people, because the most resilient generalists are the species we consider pests — cockroaches, say, or mosquitoes. “As we lose insect diversity, we’re seeing an increase in pest species,” she said.

We’re losing pollinators. We’re losing the food other animals eat. We’re losing the bugs that bury poop and dead things and help return waste to the soil.

And the culprit, inconveniently, is us. The biggest threat to insect species is habitat loss caused by agriculture, logging and infrastructure development. And that makes stopping the loss of insects difficult, Peterson told me. Often the people who need the bugs the most — for example, the Nebraska farmers who rely on burying beetles to serve as undertakers for the dead frogs and mice that help make their farmland fertile — are also the people whose livelihoods depend on destroying those bugs’ habitat. This beetle was native to the prairie, Peterson said. There’s not much prairie left and, consequently, not many beetles. But the beetles helped make the rich prairie soil, which made their habitat a great place to convert into the farmland that wrecked the beetles’ own homes. If they die off, that’s not good for farmers. But farmers also can’t just stop farming, because a prairie can’t feed humans.

There are no easy answers. In Nebraska, Peterson said, the Environmental Protection Agency now requires farmers who want to use insecticides to first make sure that there aren’t burying beetles on their land. If they find these helpful bugs, farmers have to use a more expensive insecticide that can kill pests while protecting the beetles. Peterson sees this as a trade-off: Spend a little more money now on insecticide so you don’t have to spend as much on fertilizer later. But the world is full of millions of conflicts like this — as many as there are species of insects, probably. There’s almost no way to make everybody, insects and humans, happy. The bugs might weigh more than us — for now — but we might not really feel that weight until it’s gone.

Footnotes

We continue to have … complications … since we often come back to these children almost a year after they first submitted their questions. Last time, our toddler didn’t even remember asking the question — or care about the response. This time, young Carson slipped in an extra layer to his original question, asking about the weight of all the animals (presumably just the non-bug ones?) as well. We have strategically chosen to ignore this burst of youthful curiosity because we had already written the article and, as everyone knows, no backsies.

This estimate was based on population levels from 2005. It’s probably a little higher now.

One hectare is equal to a little less than 2.5 acres, and an acre is about the size of a soccer field.

fivethirtyeight.com

How Many Individual Insects Exist In The World?

How Many Individual Insects Exist In The World?

You don’t need to be told that insects are the most abundant animals on earth. Researchers think that insects account for eighty percent of all animal life on the planet. So far scientists have discovered and described well over ninety thousand different insect species, and this is only within the United States. Amazingly, experts believe that this astronomical amount does not even account for half of all insect species in the US, including the insects that have yet to be discovered, of course. However, not all scientists agree with this assessment, as many of them claim that there remains about seventy three thousand more insect species in the US to discover. The global bug population, on the other hand, is obviously far larger, with more than nine hundred thousand insect species described so far. According to studies conducted by Terry Erwin of the Smithsonian Institution’s Department of Entomology, thirty million insects are currently inhabiting Latin America. To put it as simply as possible, different experts have agreed that the number of individual insects in the world far exceeds the trillions. In fact, it is believed that there are ten quintillion individual insects on earth, and that is a lot of zeros, nineteen zeros to be exact.

The United States does not contain nearly as many insect species as Latin America, which many people will find to be a good thing. Most of the insects that dwell within the US fall into four insect orders: Coleoptera at 23,700, Diptera at 19,600, Hymenoptera at 17,500, and Lepidoptera at 11,500. Coleoptera and Diptera are beetles and flies respectively. Hymenoptera make up a large group of insects, as they include bees, wasps and ants. There are likely many more Hymenoptera species to be found in the world. Finally, the Lepidoptera order includes moths and butterflies, which are decreasing in numbers with each passing year.

Do you think that you have multiple insect species living in your home with you?

www.azpest.com

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