# Global insect declines: Why aren't we all dead yet?

One study on a German nature reserve found insect biomass (e.g., kilograms of insects you’d catch in a net) has declined 75% over the last 27 years. [Here’s a good summary](https://www.scientificamerican.com/article/insect-ldquo-armageddon-rdquo-5-crucial-questions-answered/) that answered some questions I had about the study itself.

[Another review study](http://science.sciencemag.org/content/345/6195/401.full?casa_token=Ly2o2CDnxqAAAAAA:mCjMHV605bNqnZ_uapd7X4xLovihV2JLKzqbw2OslZwW20bY-CVhty1Ah86nE1-zu110o0a7djs) found that, globally, invertebrate (mostly insect) abundance has declined 35% over the last 40 years.

Insects are important, [as](https://en.wikipedia.org/wiki/Insect_ecology) [I’ve](https://www.theguardian.com/environment/2013/may/21/insects-cockroach-bed-bugs-environment) [been](http://thescienceexplorer.com/nature/what-would-happen-if-all-earth-s-insects-vanished) [told](https://fivethirtyeight.com/features/the-bugs-of-the-world-could-squish-us-all/) [repeatedly](http://www.bbc.co.uk/earth/story/20150211-whats-the-most-dominant-life-form) ([and written about myself](https://eukaryotewritesblog.com/2017/05/29/beespotting-on-i-5/)). So this news begs a very important and urgent question:

Why aren’t we all dead yet?

This is an honest question, and I want an answer. Insects are among the [most numerous animals on earth](https://eukaryotewritesblog.com/how-many-neurons-are-there/) and central to our ecosystems, food chains, etcetera. 35%+ lower populations are the kind of thing where, if you’d asked me to guess the result in advance, I would have expected marked effects on ecosystems. By 75% declines – if the German study reflects the rest of the world to any degree – I would have predicted literal global catastrophe.

Yet these declines have been going on for apparently decades apparently consistently, and the biosphere, while [not exactly](http://lmgtfy.com/?q=what+is+global+warming%3F%3F%3F%3F!!!) [doing great](http://lmgtfy.com/?q=what+is+chytridiomycosis+(and+how+do+I+pronounce+it)), hasn’t literally exploded.

So what’s the deal? Any ideas?

  

Speculation/answers welcome. Try to convey how confident you are and what your sources are, if you refer to any.

(If your answer is “the biosphere _has_ exploded already”, can you explain how, and why that hasn’t changed trends in things like [global crop production](http://www.earth-policy.org/images/uploads/graphs_tables/indicator3_2013_ProductionGrain.PNG) or [human population growth](https://ourworldindata.org/world-population-growth)? I believe, and think most others will agree, that various parts of ecosystems worldwide are obviously being degraded, but not to the degree that I would expect by drastic global declines in insect numbers (especially compared to other well-understood factors like carbon dioxide emissions or deforestation.) If you have reason to think otherwise, let me know.)

  
_Crossposted from [my personal blog](https://eukaryotewritesblog.com/2018/04/01/open-question-insect-declines-why-arent-we-dead-already/). Also see [Brian Tomasik's comment](https://eukaryotewritesblog.com/2018/04/01/open-question-insect-declines-why-arent-we-dead-already/comment-page-1/#comment-1442) on the original post, which I haven't assessed in detail but which seems important._