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This study appears to be an alarmist rehash of what was previously discussed on HN: https://news.ycombinator.com/item?id=14323533 https://news.ycombinator.com

This study appears to be an alarmist rehash of what was previously discussed on HN: https://news.ycombinator.com/item?id=14323533 https://news.ycombinator.com/item?id=14323533 Here's one of the original papers: https://www.farmlandbirds.net/sites/default/files/Orbrioch%20Nature%20reserve.pdf https://www.farmlandbirds.net/sites/default/files/Orbrioch%2... 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. Shocking, simply shocking! 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.

wazoox 9y ago
To people that were driving 20 years ago and are now, it was pretty obvious without any statistics that something was wrong, for several years now. 25 years ago, I couldn't drive 500 km in summer without scraping off a thick crust of dead bugs on my windshield afterwards (it was even common to stop just for that). In the past few years, I've driven thousands of km across Europe in summer with barely a dead bug on my windows.
- Traubenfuchs 9y ago
  Insects got smarter and learned to avoid streets.
- arekkas 9y ago
  I made a road trip this year from Germany to France to Spain to Gibraltar and back (~8.000 km) and had at most one or two bugs on the windshields every couple of days. I am 28 and thought this is normal, but it's so obvious that it isn't.
- giardini 9y ago
  Has traffic increased in the last 20-25 years? It has where I live. Even with the same bug population, more traffic means fewer bugs/car/trip. And cars today are more aerodynamic.
titzer 9y ago
> So alarmists are extrapolating from two data points (years 1989 and 2013) for a 220-hectare plot of German farmland to the entire world. Actually the study is couched in a lot of careful caveats and they _don't_ extrapolate to the rest of the world. I didn't see any extrapolation. And, if you read the actual article that you linked above, a decline of 2/3 from 1970 was measured in Scotland. That's corroborating evidence that ought to be carefully considered. > Actually they're not even measuring that, they're measuring the weight of dead bugs' soaked in 70-80% alcohol. Are you f'in serious? You don't even trust them to be able to properly factor out the weight of alcohol? That's not being critical, that's just disbelief. > I could go on and on about controls in statistical experiments but I think you get the idea. I think it's easy to throw out such statements on HN but I think you get the idea.
- giardini 9y ago
  titzer sez: "Actually the study is couched in a lot of careful caveats and they _don't_ extrapolate to the rest of the world. I didn't see any extrapolation." Others are using the article as support for far-fetched claims. AFAICT a 220-acre study in the hinterlands of Germany with two data points (two samples, one in 1989 and one in 2013) is causing worldwide headlines claiming a collapse of bug population: https://www.google.com/search?&q=75%25+decline+over+27+years https://www.google.com/search?&q=75%25+decline+over+27+years titzer sez: " You don't even trust them to be able to properly factor out the weight of alcohol?" You missed my point: My point was that they measure the weight of a mass of unclassified insects + alcohol + whatever else was in the trapping fluid and that they weren't presenting statistics based on insect count or insect species or insect age, health, etc. Beetles weight more than mosquitoes for example but we aren't being presented statistics for specific insect species/age/health/etc, we're being presented statistics for a mass of unclassified insects + absorbed alcohol + whatever else. Any gross measure of insect biomass is highly variable depending on bug species, population, location, predation, food supply, season, disease, etc. If you do your harvesting immediately after , say, the cicadas emerge, you'll get lots of insect biomass. Do it a six weeks later and the biomass will plummet precipitously. So you must design your experiments to take such possibilities into account. titzer sez: "That's not being critical, that's just disbelief." And that is a poor attempt at use of a broad brush to tar someone. I _am_ skeptical of the studies, as any scientist should be. You may, like others, read confirmation from your car's front bumper, but I prefer experiments with proper controls and measurements when we're speaking of good science. And, of course, I am always wary of field experiments that may involve the use of ethyl (drinking) alcohol: Hans: Sorry, Hauser, I yust panicked and ran. Does it hurt much? Hauser, Hauser, are you drunk??? Hauser: My hands are on fire. Zat's the last time I try to throw a hornets nest! Good thing we have a handy pain-killer available! Zis bug juice is hardly working though; zese stings are killing me! Pass me zat other bottle. Hans: Scheiss, Hauser, you're drinking ze bugs from ze data collection!! Vat the hell we gonna use for data? Hauser: Zis trip is a catastrophe! Scheiss! I know what! Ve can give the data to Schneider. He said he can prove anything with almost any data. Once he told me, Schneider told me, "ze less data, ze better!" He says no one pays attention to real statistics anymore.
anigbrowl 9y ago
I don't take this result at face value or consider it definitive, but it's one imperfect result among many other imperfect reports that all point in the same troubling direction. Alarms have a very useful function: to alert you to impending danger. That's why it's useful to conduct fire drills and spend some time/money on tools and methods that you hope never to have to use, notwithstanding the cost of occasional false positives. I've noticed that people who say 'oh you worry too much' are never around to help when things actually go wrong, so I pay increasingly little attention to drive-by naysayers.

wazoox 9y ago

To people that were driving 20 years ago and are now, it was pretty obvious without any statistics that something was wrong, for several years now. 25 years ago, I couldn't drive 500 km in summer without scraping off a thick crust of dead bugs on my windshield afterwards (it was even common to stop just for that). In the past few years, I've driven thousands of km across Europe in summer with barely a dead bug on my windows.

Traubenfuchs 9y ago
Insects got smarter and learned to avoid streets.
arekkas 9y ago
I made a road trip this year from Germany to France to Spain to Gibraltar and back (~8.000 km) and had at most one or two bugs on the windshields every couple of days. I am 28 and thought this is normal, but it's so obvious that it isn't.
giardini 9y ago
Has traffic increased in the last 20-25 years? It has where I live. Even with the same bug population, more traffic means fewer bugs/car/trip. And cars today are more aerodynamic.

titzer 9y ago

> So alarmists are extrapolating from two data points (years 1989 and 2013) for a 220-hectare plot of German farmland to the entire world. Actually the study is couched in a lot of careful caveats and they _don't_ extrapolate to the rest of the world. I didn't see any extrapolation. And, if you read the actual article that you linked above, a decline of 2/3 from 1970 was measured in Scotland. That's corroborating evidence that ought to be carefully considered. > Actually they're not even measuring that, they're measuring the weight of dead bugs' soaked in 70-80% alcohol. Are you f'in serious? You don't even trust them to be able to properly factor out the weight of alcohol? That's not being critical, that's just disbelief. > I could go on and on about controls in statistical experiments but I think you get the idea. I think it's easy to throw out such statements on HN but I think you get the idea.

giardini 9y ago
titzer sez: "Actually the study is couched in a lot of careful caveats and they _don't_ extrapolate to the rest of the world. I didn't see any extrapolation." Others are using the article as support for far-fetched claims. AFAICT a 220-acre study in the hinterlands of Germany with two data points (two samples, one in 1989 and one in 2013) is causing worldwide headlines claiming a collapse of bug population: https://www.google.com/search?&q=75%25+decline+over+27+years https://www.google.com/search?&q=75%25+decline+over+27+years titzer sez: " You don't even trust them to be able to properly factor out the weight of alcohol?" You missed my point: My point was that they measure the weight of a mass of unclassified insects + alcohol + whatever else was in the trapping fluid and that they weren't presenting statistics based on insect count or insect species or insect age, health, etc. Beetles weight more than mosquitoes for example but we aren't being presented statistics for specific insect species/age/health/etc, we're being presented statistics for a mass of unclassified insects + absorbed alcohol + whatever else. Any gross measure of insect biomass is highly variable depending on bug species, population, location, predation, food supply, season, disease, etc. If you do your harvesting immediately after , say, the cicadas emerge, you'll get lots of insect biomass. Do it a six weeks later and the biomass will plummet precipitously. So you must design your experiments to take such possibilities into account. titzer sez: "That's not being critical, that's just disbelief." And that is a poor attempt at use of a broad brush to tar someone. I _am_ skeptical of the studies, as any scientist should be. You may, like others, read confirmation from your car's front bumper, but I prefer experiments with proper controls and measurements when we're speaking of good science. And, of course, I am always wary of field experiments that may involve the use of ethyl (drinking) alcohol: Hans: Sorry, Hauser, I yust panicked and ran. Does it hurt much? Hauser, Hauser, are you drunk??? Hauser: My hands are on fire. Zat's the last time I try to throw a hornets nest! Good thing we have a handy pain-killer available! Zis bug juice is hardly working though; zese stings are killing me! Pass me zat other bottle. Hans: Scheiss, Hauser, you're drinking ze bugs from ze data collection!! Vat the hell we gonna use for data? Hauser: Zis trip is a catastrophe! Scheiss! I know what! Ve can give the data to Schneider. He said he can prove anything with almost any data. Once he told me, Schneider told me, "ze less data, ze better!" He says no one pays attention to real statistics anymore.

anigbrowl 9y ago

I don't take this result at face value or consider it definitive, but it's one imperfect result among many other imperfect reports that all point in the same troubling direction. Alarms have a very useful function: to alert you to impending danger. That's why it's useful to conduct fire drills and spend some time/money on tools and methods that you hope never to have to use, notwithstanding the cost of occasional false positives. I've noticed that people who say 'oh you worry too much' are never around to help when things actually go wrong, so I pay increasingly little attention to drive-by naysayers.