3 ms·

This study appears to be yet another alarmist rehash of what has been previously discussed on HN: https://news.ycombinator.com/item?id=14323533 https://news.yco

This study appears to be yet another alarmist rehash of what has been 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%2.. 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. 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.

moultano 8y ago
There have been many subsequent studies in different regions all cited in the article and all finding a precipitous decline.
- giardini 8y ago
  moultano says>"There have been many subsequent studies in different regions all cited in the article and all finding a precipitous decline.". Nope, wrong on both counts. All the article says is that professional researchers are _looking_for_data_sets_! From the article [underscores mine]: "Since the Krefeld study came out, researchers have begun searching for other forgotten repositories of information that might offer windows into the past. Some of the Radboud researchers have analyzed long-term data, belonging to Dutch entomological societies, about beetles and moths in certain reserves; they found significant drops (72 percent, 54 percent) that mirrored the Krefeld ones. Roel van Klink, ...is _looking_for_ historical data sets... So far he has found forgotten data from 140 old data sets for 1,500 locations that _could_be_resampled_. In the United States, one of the few long-term data sets about insect abundance comes from the work of Arthur Shapiro, an entomologist at the University of California, Davis. In 1972, he began walking transects in the Central Valley and the Sierras, counting butterflies. He planned to do a study on how short-term weather variations affected butterfly populations. But the longer he sampled, the more valuable his data became, offering a signal through the noise of seasonal ups and downs. “And so here I am in Year 46,” he said, nearly half a century of spending five days a week, from late spring to the end of autumn, observing butterflies. In that time he has watched overall numbers decline and seen some species that used to be everywhere — even species that “everyone regarded as a junk species” only a few decades ago — all but disappear. Shapiro believes that Krefeld-level declines are likely to be happening all over the globe. “But, of course, I don’t cover the entire globe,” he added. “_I_cover_I-80_.” ... One is a pilot project in Germany similar to the Danish car study.
  - moultano 8y ago
    I don't think you even read the quotes you posted, let alone the whole article. How does the second one you posted not meet your criteria? You also missed one. a study just out from Proceedings of the National Academy of Sciences that he labeled, “Krefeld comes to Puerto Rico.” The study included data from the 1970s and from the early 2010s, when a tropical ecologist named Brad Lister returned to the rain forest where he had studied lizards — and, crucially, their prey — 40 years earlier. Lister set out sticky traps and swept nets across foliage in the same places he had in the 1970s, but this time he and his co-author, Andres Garcia, caught much, much less: 10 to 60 times less arthropod biomass than before. (It’s easy to read that number as 60 percent less, but it’s sixtyfold less: Where once he caught 473 milligrams of bugs, Lister was now catching just eight milligrams.)

moultano 8y ago

There have been many subsequent studies in different regions all cited in the article and all finding a precipitous decline.

giardini 8y ago
moultano says>"There have been many subsequent studies in different regions all cited in the article and all finding a precipitous decline.". Nope, wrong on both counts. All the article says is that professional researchers are _looking_for_data_sets_! From the article [underscores mine]: "Since the Krefeld study came out, researchers have begun searching for other forgotten repositories of information that might offer windows into the past. Some of the Radboud researchers have analyzed long-term data, belonging to Dutch entomological societies, about beetles and moths in certain reserves; they found significant drops (72 percent, 54 percent) that mirrored the Krefeld ones. Roel van Klink, ...is _looking_for_ historical data sets... So far he has found forgotten data from 140 old data sets for 1,500 locations that _could_be_resampled_. In the United States, one of the few long-term data sets about insect abundance comes from the work of Arthur Shapiro, an entomologist at the University of California, Davis. In 1972, he began walking transects in the Central Valley and the Sierras, counting butterflies. He planned to do a study on how short-term weather variations affected butterfly populations. But the longer he sampled, the more valuable his data became, offering a signal through the noise of seasonal ups and downs. “And so here I am in Year 46,” he said, nearly half a century of spending five days a week, from late spring to the end of autumn, observing butterflies. In that time he has watched overall numbers decline and seen some species that used to be everywhere — even species that “everyone regarded as a junk species” only a few decades ago — all but disappear. Shapiro believes that Krefeld-level declines are likely to be happening all over the globe. “But, of course, I don’t cover the entire globe,” he added. “_I_cover_I-80_.” ... One is a pilot project in Germany similar to the Danish car study.
- moultano 8y ago
  I don't think you even read the quotes you posted, let alone the whole article. How does the second one you posted not meet your criteria? You also missed one. a study just out from Proceedings of the National Academy of Sciences that he labeled, “Krefeld comes to Puerto Rico.” The study included data from the 1970s and from the early 2010s, when a tropical ecologist named Brad Lister returned to the rain forest where he had studied lizards — and, crucially, their prey — 40 years earlier. Lister set out sticky traps and swept nets across foliage in the same places he had in the 1970s, but this time he and his co-author, Andres Garcia, caught much, much less: 10 to 60 times less arthropod biomass than before. (It’s easy to read that number as 60 percent less, but it’s sixtyfold less: Where once he caught 473 milligrams of bugs, Lister was now catching just eight milligrams.)