[HN Gopher] Bugs Matter: counting insect 'splats' on vehicle num...
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Bugs Matter: counting insect 'splats' on vehicle number plates
[pdf]
Author : Kaibeezy
Score : 74 points
Date : 2022-05-05 07:38 UTC (15 hours ago)
(HTM) web link (cdn.buglife.org.uk)
(TXT) w3m dump (cdn.buglife.org.uk)
| calebegg wrote:
| See also: https://en.wikipedia.org/wiki/Windshield_phenomenon
| Wistar wrote:
| It used to be--80s and early 90s--that a couple hundred mile
| drive down the Oregon coast would need at least one or two stops
| for bug splat removal. I made that drive last July and there were
| perhaps two splats for the entire 400-mile round trip.
| moron4hire wrote:
| I remember being at minor league baseball games in the 90s,
| waiting for dark to see fireworks after the game, and getting
| absolutely rained on by moths falling from getting cooked in
| the stadium lights. The cloud of moths would be so thick it
| would partially obscure the lights. The girls would scream and
| the boys would scoop up handfuls from the ground to throw at
| the girls.
|
| ... Not me. Other boys.
|
| Anyway. I don't think the mosquitoes got the memo. I feel like
| I get more and more bites every year.
| dvh wrote:
| '80s cars are not exactly known for their aerodynamics...
| _____ ___/__|__\__ [ \__|__/ ] '(
| )------( )=
| PheonixPharts wrote:
| This is the classic "this is fine" response whenever someone
| posts this observation about declining insect populations and
| cleaning dead bugs off of cars.
|
| However a _tiny_ bit of investigation into this will lead you
| to realize that this hypothesis is false.
|
| More than just being false, research has discovered that
| modern cars hit _more_ insects than less aerodynamic cars
| [0]:
|
| > The research included vintage cars up to 70 years old to
| see if their less aerodynamic shape meant they killed more
| bugs, but it found that modern cars actually hit slightly
| more insects.
|
| So, given what research has shown us, we should expect there
| to be _more_ insects observed if it were the case that insect
| populations remained stable while cars became more
| aerodynamic.
|
| 0. https://www.theguardian.com/environment/2020/feb/12/car-
| spla...
| jgraham wrote:
| Right, the quote from the linked paper is:
|
| > This is contrary to a suggestion that finding fewer
| insects on number plates in recent years might be
| attributed to increasing streamlining of vehicle
| aerodynamics over time. Our data show that newer vehicles
| sample more insects than older vehicles, and we have
| observed pattern of fewer insects on number plates more
| recently than in the past in spite of this effect of
| vehicle age, which is assumed to be correlated with
| aerodynamics.
|
| In fact the researchers posit a few more possiblities other
| than collapse of insect populations that could explain
| their data. For example they can't eliminate the
| possibility that there's some change in the management of
| roadside verges that specifically decreases the insect
| population in those environments, without reducing the
| population in other environments.
|
| The challenge for all the explainations which involve
| something other than population change is that there's now
| an increasing nubmer of studies using different techniques
| which consistently show declining populations. For example
| [1] uses Malaise traps in nature reserves, which presumably
| wouldn't be affected by roadside management practices, and
| finds a ~75% decrese in flying insect biomass over 27
| years, whereas [2] uses light trap data to look at moths
| specifically and finds a ~40% decline in biomass over 50
| years (and ~50% in woodlands).
|
| Whilst it's possible to find studies that show increases in
| insect numbers e.g. as a result of site-specific
| conservation work, there's a lot of data suggesting that in
| Europe at least numbers are in significant decline. As far
| as I can tell (and I'm really not an expert) we don't
| understand the reasons all that well, but habitat
| fragmentation and pesticide use are leading theories. We at
| least know that common pesticides (notably, but not
| exclusively, neonicotinoids) are toxic to bees, and will
| reduce populations even at sub-lethal doses (e.g. [3]). So
| changing our agricultral practices to eliminate these
| chemicals looks like a necessary, but perhaps not
| sufficient, part of the solution.
|
| [1] https://journals.plos.org/plosone/article?id=10.1371/jo
| urnal... [2] https://resjournals.onlinelibrary.wiley.com/do
| i/10.1111/icad... [3] https://citeseerx.ist.psu.edu/viewdoc
| /download?doi=10.1.1.66...
| gonzo wrote:
| Not if the aerodynamic cars from a decade ago significantly
| impacted insect populations.
| Kaibeezy wrote:
| _Less than half of 1% of the land area in the United
| States is covered by roads of all kinds, not including
| rights-of-way, parking lots, and driveways._
|
| National Academies of Sciences, Engineering, and
| Medicine. 2005. _Assessing and Managing the Ecological
| Impacts of Paved Roads._ Washington, DC: The National
| Academies Press. https://doi.org/10.17226/11535.
| thaumasiotes wrote:
| There is every reason to expect that the flying insects
| near paved roads today are less likely to die in
| encounters with cars than the flying insects near roads
| of 40 years ago.
|
| But it would be very difficult to measure that effect.
| Wistar wrote:
| Last summer's trip was in a Mercedes GLK, not exactly the
| paragon of slipperiness.
| Steltek wrote:
| The majority of US cars are huge SUVs and pickup trucks. I
| would dare say 80's cars are more aerodynamic simply by
| having a smaller cross section.
| drewzero1 wrote:
| Not necessarily. Windshields were less curved and more
| vertical, body panels were much less contoured, and
| features like sealed-beam headlights, mirrors (if
| equipped), and windshield wipers were more protuberant. A
| 1980s Mercury Grand Marquis had a drag coefficient of 0.46,
| while a 2018 Ram 1500 is listed at 0.357 (less is better).
| Obviously some 80s cars fared better, mostly compacts like
| my '83 SAAB 900 (3.7, not on the list below) or sports
| cars. I just picked the Mercury as a typical full-sized
| family sedan.
|
| Here's a big list, for anyone interested in some numbers:
| https://en.wikipedia.org/wiki/Automobile_drag_coefficient
| wtallis wrote:
| Coefficient of drag normalizes relative to cross
| sectional area. Pointing out that a modern Ram 1500 has a
| lower Cd than an old Mercury doesn't mean the Ram has
| less drag. If the Ram's cross sectional area is 30%
| larger, it will have more drag than the Mercury despite
| having a more aerodynamic shape.
| drewzero1 wrote:
| Thanks for pointing this out; I was unaware. There's also
| a table of cross-sections later in the linked Wikipedia
| page, but I hadn't paid much attention to it because of
| not knowing how to perform a meaningful comparison.
| [deleted]
| narag wrote:
| There's this assumption, not explicit, but floating around
| this thread, that aerodynamics somehow makes splats more
| difficult.
|
| I can't really refute it, but it doesn't ring true to me
| either.
|
| Insects don't even touch the car before exploding, mind you.
| zevv wrote:
| I have been driving the exact car from this drawing for the
| last 25 years: Volvo 940, square as a brick.
|
| In the 90s, it needed a weekly scrub to keep the headlights
| and plate visible.
|
| I have literally not washed my car a single time over the
| last year. It has moss and pollen all over, but there are
| hardly any bug splats.
|
| This frightens me _so_ very much.
| ErikVandeWater wrote:
| Somewhat off topic - Did you draw that car yourself, or did
| you copy it from somewhere? It's great!
| gerdesj wrote:
| The article's title specifically mentions "number plates".
| All cars in the UK are required to display number plates
| (license plates) at the front and back. They have a standard
| size. They are nearly all (99% or more) in the centre and are
| roughly the same height off the ground, depending on model.
|
| My first Mark 1 Ford Fiesta from 198something had its plate
| at about the same place as the Honda S2000 I had in
| 200something and the Renault CLio I have now and the Ford
| Transit van I also drive.
|
| The S2000 did the best doughnuts though. Rear wheel drive,
| variable valves, 13,500 RPM red line and quite a lot of
| welly.
| brimble wrote:
| This was the case in the Midwest in our basically-the-same-
| shape-as-modern-cars 90s family cars. We'd use the windshield
| cleaner thing next to the gas pump nearly every time we
| stopped, when on road trips, and for good reason--there'd be a
| few large splatters and a bunch of smaller ones, every time.
| And that's if it wasn't particularly buggy out that day--there
| were some times we stopped _for the windshield_ , not for gas.
|
| I think I've done that like... four or five times, total, since
| the year 2000. And I think every time it was for a _single_ big
| bug-splatter.
|
| [EDIT] I also recall there being _tens_ of times more large
| insects--butterflies, large moths, grasshoppers, katydids--
| around _in general_ back in the late 80s and early 90s, even in
| the 'burbs, like they were just all over the place in the
| Spring and Summer, you'd walk through lawn-length grass at the
| school playground and tons of them would be all around you,
| hopping away or taking to the air, and now I have to try pretty
| hard to find even one... but surely that can't be right, can
| it? That'd be _super_ noticeable by scientists who track that
| kind of thing. Right?
| throwaway894345 wrote:
| I've been driving all over the midwest and my car is covered
| in splats after each trip. This seems really surprising to
| me.
| [deleted]
| Gys wrote:
| A 26 page research report with a clear conclusion:
|
| > The results show that the number of insects sampled on vehicle
| number plates in the UK decreased by 58.5% between 2004 and 2021,
| and that these differences were statistically significant. A
| comparison of the 2004 national data with the 2019 data from Kent
| showed a 53.7% decrease. The greatest decreases in splat rate
| between 2004 and 2021 occurred in England (65%) whilst journeys
| in Scotland recorded a comparably smaller decrease (27.9%), with
| intermediate decreases in Wales (55%).
| qiskit wrote:
| It could be evolution - insects with traits that kept them from
| cars were selected for. Perhaps changes to the license plates?
| Changes in the design of cars? Or a general decline of insect
| population?
| markburns wrote:
| Completely anecdotal but I seem to remember flies banging
| their heads on windows a lot more when I was younger.
|
| Now they seem to be able to navigate their way out with
| comparative ease. Open a door or window and waft them in the
| general direction and they seem to be able to escape.
|
| I've been wondering for a few years if this was evolution.
| brewdad wrote:
| I've had two birds fly into my living room window this
| week. I haven't even cleaned it recently. The flies may be
| evolving but robins have a ways to go yet.
| sigmoid10 wrote:
| Please tell me where you live so I can move there. My flies
| are as dumb as ever, I can't even get them to go out the
| window with me actively trying to kill them. They rather
| take their chances with the swatter or get tangled behind
| the curtains.
| markburns wrote:
| The UK. Maybe you stress them out :)
| sigmoid10 wrote:
| From an evolutionary perspective it would seem wrong to
| actively go towards the source of stress when the
| opposite direction clearly leads to safety. But then
| again what do I know. Perhaps my flies are adrenaline
| junkies.
| yreg wrote:
| The more aerodynamic the car is the less splats there should
| be, as the bugs are more likely to be carried by the flow of
| air around the car, correct?
|
| Still, there is no doubt that the insect population is in a
| massive decline.
| PheonixPharts wrote:
| > The more aerodynamic the car is the less splats there
| should be, as the bugs are more likely to be carried by the
| flow of air around the car, correct?
|
| _incorrect_
|
| As I've pointed out in another comment, research has shown
| [0] that counter-intuitively "modern cars actually hit
| slightly more insects."
|
| It's a reasonable hypothesis, however what this research
| shows is that we would have expected to see _more_ dead
| insects on cars had populations remained stable.
|
| 0. https://www.theguardian.com/environment/2020/feb/12/car-
| spla...
| meetups323 wrote:
| Research is research, but anecdotes are anecdotes. And
| anecdotally, I can tell you that having done the same
| drive in the same conditions many times with both a Jeep
| Wrangler and a Toyota Prius, the Wrangler consistently
| has _far_ more bugs on it, and requires multiple
| cleanings per leg of the journey. The Prius requires no
| cleanings for the duration of the trip.
| throwaway0a5e wrote:
| >The more aerodynamic the car is the less splats there
| should be, as the bugs are more likely to be carried by the
| flow of air around the car, correct?
|
| It depends on what the nature of the airflow around a
| specific car looks like. Bugs have a harder time than air
| making a "hard corner" but the mass of air stuck at a hard
| corner can cause other air to go around in a more graceful
| way and carry the bugs with them.
|
| Coefficient of drag hasn't improved much since the 90s and
| most of those improvements have been with regard to the
| vacuum behind the car so aerodynamics is probably only a
| contributing factor either way.
| yCombLinks wrote:
| Yes, it could be that, but anecdotally I see significantly
| less bugs on cars during summers than during my childhood.
| The grill, windshield, etc would have dozens of lovebugs
| after a short drive on an early summer day. Now they're rare.
| mikestew wrote:
| I've worn the same brand and model of motorcycle helmet
| (Nolan flip-up) for probably 20 years. Granted, I'm sure
| Nolan has made some minor changes over the years, but the
| aerodynamics of my massive noggin haven't changed, and I
| clean far, _far_ fewer bugs off my face shield than in years
| past. Just my imagination? No, I have records of when I buy
| Honda Spray Cleaner and Polish (the pro 's choice for
| cleaning face shields), and I don't buy as much as I used to
| for the same miles ridden. And old post of mine from six
| months ago when the topic came up, and everyone's all like
| "cars are more aerodynamic than they used to be" (yeah, well,
| my head's not), basically saying the same thing:
|
| https://news.ycombinator.com/item?id=29006969
| [deleted]
| ISL wrote:
| If the (important/compelling/disturbing) science content wasn't
| enough, definitely open the article for terms like "Splatometer"
| and "Splats-per-mile".
| stelonix wrote:
| Could this in any way be related to the increase of wifi,
| cellular or any other EM waves that got a huge boom since the
| early 2000s? I ask this as in, is there any research on how the
| EM waves we've been using the past 20-25 years interact with
| arthropoda in general?
| jl6 wrote:
| https://en.wikipedia.org/wiki/Decline_in_insect_populations
|
| There are a lot of very plausible explanations to work through
| before you have to consider something exotic like EM
| sensitivity.
| malfist wrote:
| Probably going to regret asking this, but is there any evidence
| that EM waves interact negatively in anything in the animal
| kingdom? Outside of literally cooking something.
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