Here's one of the original papers:
The 75% decline number appears to be from two data points from a 220-acre plot. From that paper:
"What follows is a description of measured Insect-Biomasses from samples collected in the Orbroich Bruch Nature Reserve, near Krefeld, using Malaise Insect Traps. The results show that, in the same two areas, sampled in the years 1989 and 2013, there was a dramatic fall in the number of flying insects. Using the same traps, in the same areas, significant reductions of insect populations, of more than 75%, were found. Our data confirms, that in the areas studied, less than 25% of the original number of flying insects collected in 1989, were still present in 2013."
"The Orboicher Bruch, to the Northwest of Krefeld, is a designated Nature Reserve of around 100 hectares (220 acres). Due to the reserve’s relatively remote location and its rugged landscape, intensive farming came to the area only recently."
So alarmists are extrapolating from two data points (years 1989 and 2013) for a 220-hectare plot of German farmland to the entire world. I think that is a bit of a stretch, even for statistics.
Since different bugs breed in different seasons, and numbers depend on the fruitfulness of previous generations, food supply, predation, disease, temperature and so on, this bug weight could vary considerably from year to year (or site to site) for any number of reasons. While one year cicadas thrive, the next year there may be none.
BTW they're measuring the weight of dead bugs - not how many bugs or what species of bugs - just the weight of bugs. Actually they're not even measuring that, they're measuring the weight of dead bugs' soaked in 70-80% alcohol.
I could go on and on about controls in statistical experiments but I think you get the idea.
See the original HN posting for discussions pointers to the earlier papers.
Global declines in insects have sparked wide interest among scientists, politicians, and the general public. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services. Our understanding of the extent and underlying causes of this decline is based on the abundance of single species or taxonomic groups only, rather than changes in insect biomass which is more relevant for ecological functioning. Here, we used a standardized protocol to measure total insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany (96 unique location-year combinations) to infer on the status and trend of local entomofauna. Our analysis estimates a seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over the 27 years of study. We show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline. This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning in the European landscape.
If we were to exchange "philosophical" considerations here, I'd tell you that sunday fishermen have complained weekly that there was much more fish in the river before since the dawn of humanity. I'd also tell you that my own home in downtown Beijing has seen a slug invasion this year, and that these animals are not disappearing at all (at least in my courtyard).
Planet of weeds
Tallying the losses of Earth’s animals and plants
By David Quammen/Harpers Magazine
Obviously, there is probably some bias due to this being in part from a conservation advocacy group. However, the methodology does appear to be documented in a peer-reviewed paper . So I'd personally give it a fair more weight than mere anecdote.
if you keep panning, you'll find yourself looking at mostly forest and farmland with the former prevailing. you may find an occasional city, but the vast of what you will find is nature for the next 1700 miles. by then you reached the rocky moutains and things start to get a bit drier.
Nature is ok. nature is not dead. and as per comments bellow, you do not take two data points and extrapolate a linear prediction and expect anything meaningful. let alone from one small area in Germany, using a methodology that has not been widely tested. its certainly cause for additional research.
Is there still lots of plant cover? Sure. But when you get into what types of environments are intact and healthy enough to support the normal fauna, we start to see problems. So there may be forest, but there may now be a tremendous drop in the amount of wildlife in the forest because the food chain has been badly damaged.
Insects form the foundation of many ecosystems and massive drops in insect biomass would be devastating to all of the animals up that food chain. And there are a number of reasons insects can be disappearing from pesticides, to loss of specific species of plants, to air pollution.
Even if we continue on our path of anthropomorphic mass extinctions, life on Earth will adapt and move on, that's not in question. But Earth may not be very hospitable for human kind if we don't change course.
Populations become more educated, have fewer children. The power of technology and bio technology grows at a far faster rate than population. In the 1920s an acre of land would get you about 40-50 bushels of corn. A short 100 years into the future and we're averaging 180-190. We have barely even scratched the service when it comes to advancing the base breeding stock with genetics. Biotech traits (roundup ready, etc) have given us a big boost, but they too are just the tip of the iceberg. CRISPR is going to make yields skyrocket.
I know the news loves showing you doom and gloom, but really, humans have never had it better and it isn't going to stop.
More awesome statistics here: http://www.humanprogress.org/
My background is in physics, and in physics we deal with constraints- thermodynamics, conservation of energy, and so on. I'm telling you that no matter what technology we develop certain constraints are inescapable. Crop yields can only increase so much. If we restrict the domain of discussion to the surface of the earth, then we're left with limits. That doesn't necessarily imply a Malthusian scenario! But it means that we need to plan for a time when exponential growth is no longer the rule. I mean, there is nothing normal or sustainable about this wacky, unbalanced moment of time that we live in. I don't know how it ends- with a plateau or a bust- but sometime I would say this century it has to end. Look: if you assume 3% year on year productivity growth per person, in around 700 years every person is producing as much goods and services as all 7 billion of us do today. That's clearly preposterous. Your fingers could not move fast enough to write that much code, compose that much music, and your little human brain could not appreciate it all anyway if everyone was producing that much art, let alone all the physical work. The question is just how long we have left before that growth flattens out, and what happens next.
> quite obviously
I don't know about you, but for me such words are huge red flags - especially without hard data.
Birds populations face steep decline
Common Birds in Steep Decline List
Global collapse in huge songbird population
Dramatic decline of bird population in Germany
Sharp decline of birds in UK
Towards understanding large mammal population declines in Africa’s protected areas
Global decline in aggregated migrations of large terrestrial mammals
Marine Fish Population Collapses
Has Half of World's Wildlife Been Lost in Past 40 Years?
Marine population halved since 1970
Half of Great Barrier Reef Lost in Past 3 Decades
Since when asking for sources is "playing a game"?
Asking for sources so that you can examine the data yourself is admirable. Asking for sources because certain words "trigger red flags" for you that the other party is not acting in good faith is a different problem.
"In philosophy and rhetoric, the principle of charity requires interpreting a speaker's statements to be rational and, in the case of any argument, considering its best, strongest possible interpretation."
Well of course. I suspect insects of every type are now doing the equivalent of war-driving to find Monsanto free areas they can live.
Not everything you dislike about the ag sector is Monsantos doing.
1) Entirely pedantic, but Monsanto certainly is a pesticide vendor. They aren't an insecticide vendor (which is what you meant), but herbicides, insecticides, and fungicides all fall under the umbrella of "pesticides."
2) canada_dry talked about finding "Monsanto free areas," and that's still accurate. The monoculture cropping that makes herbicides necessary eliminates all the "non-productive" plants that act as habitat for pest-controlling predator species, making pesticides necessary. Monsanto may not make insecticides, but their business model depends on an agriculture system that inevitably leads to using insecticides.
Wait, is it really true that monoculture inevitably leads to pests? Yes, because ecological niches have been left unfilled, so nature steps in to fill them. Monoculture farms being overrun by pests is as unsurprising to an ecologist as an inverted broomstick falling over is to a physicist. You created an unstable system, and it's trying to return to equilibrium.
At that point you have two options. You can spend the rest of your life balancing the broomstick, or you can lean it against a wall. We can spend the remaining lifespan of our [relatively young] global civilization tilling and pouring biocides on 40% of Earth's land surface (and an assuredly short lifespan it will be, as the soils erode away, deforestation shuts down the terrestrial water cycle, the continents desertify, and the aquifers deplete), or we can adopt stable polyculture food growing systems that intentionally fill those open ecological niches with productive species.
Ecosystem engineering (working with nature) vs open-loop, leaking, unsustainable systems that only benefits chemical manufacturers and distributors.
Bees are not the worst case because they can make honey to prepare for lean times. Insects which don't stockpile long-term reserves are out of luck.
Humans have been trying to get rid of pests for centuries, Monsanto didn't start it.
How do you explain to your frogs that you woke them up?
I'm happy to hear about your insect diversity. I hope if you ever get fed up with them you'll use natural countermeasures, such as installing bird nesting booths (a great tit catches over 300 bugs per day...and it sounds nice). I mean in Africa they're starting to use bee hives to deter elephants from farms, surely you can't be worse. May the frogs and spiders be on your side.
From their "methods and materials" section:
> Biomass data were collected and archived using a standardized protocol across 63 unique locations between 1989 and 2016 (resulting in 96 unique location-year combinations) by the Entomological Society Krefeld. The standardized protocol of collection has been originally designed with the idea of integrating quantitative aspects of insects in the status assessment of the protected areas, and to construct a long-term archive in order to preserve (identified and not-identified) specimens of local diversity for future studies. In the present study, we consider the total biomass of flying insects to assess the state of local entomofauna as a group.
> All trap locations were situated in protected areas, but with varying protection status: 37 locations are within Natura2000 sites, seven locations within designated Nature reserves, nine locations within Protected Landscape Areas (with funded conservation measures), six locations within Water Protection Zones, and four locations of protected habitat managed by Regional Associations. For all location permits have been obtained by the relevant authorities, as listed in the S1 Appendix. In our data, traps located in nutrient-poor heathlands, sandy grasslands, and dune habitats provide lower quantities of biomass as compared to nutrient nutrient-rich grasslands, margins and wastelands. As we were interested in whether the declines interact with local productivity, traps locations were pooled into 3 distinct habitat clusters, namely: nutrient-poor heathlands, sandy grassland, and dunes (habitat cluster 1, n = 19 locations, Fig 1A), nutrient-rich grasslands, margins and wasteland (habitat cluster 2, n = 41 locations, Fig 1B) and a third habitat cluster that included pioneer and shrub communities (n = 3 locations).
> Most locations (59%, n = 37) were sampled in only one year, 20 locations in two years, five locations in three years, and one in four years, yielding in total 96 unique location-year combinations of measurements of seasonal total flying insect biomass. Our data do not represent longitudinal records at single sites, suitable to derive location specific trends (e.g. ). Prolonged trapping across years is in the present context (protected areas) deemed undesirable, as the sampling process itself can negatively impact local insect stocks. However, the data do permit an analysis at a higher spatial level, i.e. by treating seasonal insect biomass profiles as random samples of the state of entomofauna in protected areas in western Germany.
> Malaise traps were deployed through the spring, summer and early autumn. They operated continuously (day and night), and catches were emptied at regular intervals, on average every 11.2 days (sd = 6.3). We collected in total 1503 trap samples, with an average of 16 (4–35) successive catches per location-year combination (Table 1). Between 1989 and 2016, a total of 53.54kg of invertebrates have been collected and stored, over a total trap exposure period of 16908 days, within an average of 176 exposure days per location-year combination. Malaise traps are known to collect a much wider diversity of insect species (e.g. [29–31]) as compared to suction traps (e.g. ) and are therefore considered superior as a method of collecting flying insects. On the basis of partial assessments, we can assume that the total number of insects included in 53.54 kg biomass represents millions of individuals.
> The sampling was standardized in terms of trap construction, size and design (identical parts), colors, type of netting and ground sealing, trap orientation in the field as well as slope at the trap location. Hence none of the traps differed in any of these field aspects. Our trap model was similar to the bi-colored malaise trap model by Henry Townes [32, 33]. The traps, collecting design, and accompanying methods of biomass measurement as designed and applied by the Entomological Society Krefeld are described elsewhere [34–36] and in S2 Appendix.
> Trap catches were stored in 80% ethanol solution, prior to weighing, and total insect biomass of each catch (bottle) was obtained based on a standardized measurement protocol by first subtracting fluid content. In order to optimally preserve samples for future species determination, the insects were weighed in an alcohol-wet state. First, the alcohol concentration in the vessels was stabilized to 80%, while this concentration was controlled with an areometer over a period of at least two days. In order to obtain biomass per sample with sufficient accuracy and comparability, the measuring process was fixed using a standardized protocol . For this purpose the insects of a sample were poured onto a stainless steel sieve (10cm diameter) of 0.8 mm mesh width. This sieve is placed slightly obliquely (30 degrees) over a glass vessel. The skew position accelerates the first runoff of alcohol and thus the whole measuring procedure. The drop sequence is observed with a stopwatch. When the time between two drops has reached 10 seconds for the first time, the weighing process is performed with a laboratory scale. For the determination of the biomass, precision scales and analytical scales from Mettler company were used with an accuracy of at least 0.1g and controlled with calibrated test weights at the beginning of a new weighing series. In a series of 84 weightings of four different samples repeating this measurement procedure, an average deviation from the mean value of the measurement results of 0.4 percent was observed (unpublished results).
I suspect it's far more likely that, if humanity goes extinct, it's due to some other subtle cause, rather than one of the big headliners.
Pretty terrifying thinking about all the various pesticides in use today and wondering "Will one of these bioaccumulate and sever some critical link in an ecosystem humanity depends on?"
But what's most scary is that there are multiple credible slow or fast ways the whole of humanity is at risk, and that most are our own fault.
However, agreeing that we are indeed hastening the next mass extinction, might be a good start to avoiding/postponing it.
Great Filter here we come.
Honestly, it may not have been super effective for certain reasons, but China's child limit laws are about the least crazy solution I can think of.
but is that small enough or soon enough to avoid environmental catastrophe?
Example: I think everyone should be sterilized at birth, but it should be reversible at no cost to them. But I can't think of a single government that I'd trust to enact this policy correctly without falling into a Eugenics system.
Also, the catch is that development tends to reduce population growth. India (for example) may be growing rapidly now, but if they succeed in eliminating poverty then population will stabalise at some point. People will simply have fewer kids. So why not just wait until population stabalises naturally?
I'm not saying whether or not there are less insects, just that this is a huge confounding factor.
Perhaps someone who frequently takes classic cars for long trips at highway speeds can chime in?
We own a 1981 VW Vanagon. It's a camper, it travels. 8-9 hours to see the eclipse this summer, as just one example. These days, I clean the windshield more to get the dirt off than remove the bugs. Anecdotal, but hey, you asked. :-)
I'd estimate conservatively that during the past few summers, driving in the same areas, I see at least one third fewer splats than I did a decade ago. However, the area I live in has also had a big growth in sprawl, with lots of new housing developments especially, and that is almost certainly a factor.
Hello, fellow '05 owner! And yup, all I have to add is "me, too", because our experience has been identical.
As one last anecdotal data point to add to our VW and Scion, I keep a can of cleaner in the motorcycle tank bag to clean the helmet face shield. I used to buy stuff packs of three. Lately, I think I'm still on the can I bought three years ago. I used to also keep a little scrubby sponge in the tank bag for those extra stubborn bugs. I haven't used that thing in so long I don't even know where it's at anymore.
Sometimes science is not always about having all the answers but about thinking in the right questions.
Even if the data is not accurate, bringing attention into this matter seems a positive outcome.
I don't know why but I'm seeing a lot of anecdotes to support or dispute the linked article. The world is much bigger than any one person's experience, and the data indicates that overall, there are fewer insects. We may have anecdotes that agree or disagree with that statement, but that doesn't disprove the statement or in fact provide any useful content to the discussion.
The real question here is 1. is this a bad sign (magic 8ball says yes) and 2. what can we do about it (this is a deeper question that can't be easily answered because we haven't done in-depth analysis of why these insects have started to disappear, but the suspicion would be that large-scale agricultural and suburban pesticide use is having a much larger and potentially disastrous effect on the earth's ecosystem).
The discussion I'd like to see here is about the ways we can verify this study (trust but verify), determine the source of the problem, and work torwards eliminating that source.
I also noticed almost no mosquitos in my several trips in the summer to and passing through Germany.
The destruction of whole ecosystems and causing of many diseases (even cancer and death) is a capital a crime without any doubt. (Yes, lawyers still need to read the proof to put them on trial).