• Question: How many insects are there in the world?

    Asked by angela-holland on 25 Jun 2020.
    • Photo: Paul Eggleton

      Paul Eggleton answered on 25 Jun 2020:

      No-one really knows, but it must be many more than there are humans. So the number is in tens of billions, probably!

    • Photo: Anabel Martinez Lyons

      Anabel Martinez Lyons answered on 25 Jun 2020: last edited 25 Jun 2020 12:17 pm

      Hi Angela – fantastic question. The Smithsonian Institute in the US predicts there are as many as 10 quintillion (that’s 10,000,000,000,000,000,000) insects alive in the world on any given day, but as Paul has said it’s impossible to know exactly how many there are. This is because of difficulties in studying where they are all located, our ability to identify/count them properly, and also how quickly they live and die (some insects are only alive for hours or days at a time, which makes it difficult to know just how many are alive at one time). In terms of the number of different species of insect, there are more than 900,000 known species worldwide, and possibly many others that haven’t been discovered yet! Here is a great source if you want to learn more: https://www.si.edu/spotlight/buginfo/bugnos#:~:text=At%20any%20time%2C%20it%20is,described%20species%20is%20approximately%2091%2C000..

    • Photo: Andrew Yool

      Andrew Yool answered on 25 Jun 2020: last edited 1 Jul 2020 4:30 pm

      It’s not exactly the question you asked, but a study published a few years ago [*] estimated how much of different groups of animals, plants, bacteria, etc., there were. They did so in terms of the carbon weight of living creatures – so that’s just adding up the weight of the carbon atoms in each organism. To give you an idea of what that means, in humans about 20% of our total weight is due to carbon.
      What this study found was that there’s about 545 petagrams of carbon is in living things. One petagram is 10 to the power of 15 grams, so 1,000,000,000,000,000 grams. To avoid writing lots of zeroes, we abbreviate these units to Pg C.
      Of this, around 450 Pg C can be found in land plants (83.3%). That’s why it’s so green when you look outdoors. Of the rest, only about 2 Pg C is in animals of all kinds (0.4%). And of this, about 1 Pg C is in arthropods [**]. So insects make up a little less than 0.2% of the carbon in all of the living things on Earth.
      And to put things in perspective, humans add up to about 0.01% of all of the carbon in living things on Earth.
      Hope this answer helps!
      [*] You should be able to find it here: https://www.pnas.org/content/115/25/6506
      [**] Insects are one type of arthropods. Others are spiders and crustaceans like lobsters and crabs.

    • Photo: Alex Dye

      Alex Dye answered on 25 Jun 2020:

      As Anabel said, there are almost one MILLION species of insect which we current know about (this is different types of insect) – but some scientists think there may be as many as ten times that still left to be discovered! That’s a lot of bugs!
      But as Paul said, there may be billions and billions of insects alive in the world!

    • Photo: Aisling Ryan

      Aisling Ryan answered on 25 Jun 2020:

      Reading all of the great answers about how we couldn’t possibly know exactly how many species of insects there are I thought I’d add a little perspective. Something I find really fascinating is that although scientists have discovered around 1.7 million species of plants, they believe that there are still over 5 million species of plants that we still haven’t discovered! So considering plants don’t walk or fly around the place and are generally out in the open I think it’s definitely possible that there are a magnitude of undiscovered insects as well! (Although I am certainly no expert on this!)

    • Photo: Helen Roy

      Helen Roy answered on 25 Jun 2020:

      That’s a fantastic question – there are about 1 million insect species named globally but there are likely to be about 10 million – so many more to discover and name!

    • Photo: Jozsef Vuts

      Jozsef Vuts answered on 26 Jun 2020:

      Nobody knows it exactly. There are around 1 million DESCRIBED insect species, and they estimate that there are many million more that we haven`t yet discovered. And how many individuals altogether? That`s even more difficult (if not impossible) to tell.

    • Photo: Vikki Rose

      Vikki Rose answered on 26 Jun 2020:

      Hi Angela,

      As has already been mentioned there are around a million identified insects species currently recognised. It’s estimated there are 1.4 billion insects for every person on Earth. The total weight of all the insects is about 70 times more than all the people (quite a lot of bugs). Most authorities agree that there are more insect species that have not been described (named by science) than there are insect species that have been previously named. Conservative estimates suggest that this figure is 2 million, but estimates extend to 30 million.

      Some recently discovered species are eriovixia gryffindori (a spider said to resemble the sorting hat from Harry Potter) and Neopalpa donaldtrumpi (a moth said to resemble Donald trump). Who knows what else is out there waiting to be discovered 🙂