Research says no: “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.” From https://www.theguardian.com/environment/2020/feb/12/car-spla... (Second hand comment from a journalist; actual research results may vary).

Is it possible for there to be so many more vehicles than decades before that the number of insects hitting each car is much less?

Insects getting better at avoiding cars in a much shorter time than we'd expect would certainly be a prediction of Sheldrake's 'morphic resonance' theory.

The comment above yours was not saying what you're saying.

They were saying, IIUC, that it could be that the same amount of bugs are splattered across a larger number of cars, so that if you look at any one car, then it looks like less bugs.

That was my understanding as well, I was proposing an alternative theory.

There’s a road in my area (rural MN) where I don’t slow down if there are deer on the side of the road. It’s a curvy road with a ton of deer, and back when I was a teenager the deer would do the normal deer thing of potentially getting spooked and run across the road…or directly in to your stopped car.

15 years later they no longer do that, just on that road in particular. I don’t know if it’s evolved behavior or learned, but they absolutely changed.

We’re seeing a comparable decline in birds that depend on them for food, so probably not.

That said, it’s fun to imagine that we just selected against insects that hang out by the highway.

This has apparently happened with birds. Some bird species have evolved shorter wings for better maneuverability near traffic.

https://www.npr.org/2013/03/22/175054275/birds-evolve-shorte...

that wouldn't be strange. I remember a friend telling me about scientists who visited a remote place twice and seeing fungus-caused dieoffs the second time and he immediately claimed that it was global warming. My first thought was "those bastard scientists brought the fungus in" (I've hiked through remote endemic-plant forests and they tell you to scrub yourself vigorously on your way in to prevent tracking non-native plant seeds)

I drive my old motorcycle with the same big windshield since the 90ies. Insects are dramatically less on it now than 20 years ago.

Yup.. I'm 50 and I will attest there is NO DOUBT insects populations have declined. It's crazy.

Fellow biker here, with as small a windshield as I can stand (meaning my helmet stands above the windshield. I still carry a can of Honda Spray Cleaner and Polish in the tank bag for scrubbing the face shield on the helmet, as well as the windshield. I used to go through several cans a year. Now, for the same miles ridden, a can might last over a year. The one variable is the bike, but I've owned a variety of bikes over the decades I've been riding, and only in the last 10 years or so did I have to cut back on my standing order of cleaner.

Huge trucks and SUVs are really popular in the US. The aerodynamics are not going to compare favorably to typical 90's cars, where even the trucks are much smaller.

For me, I noticed the change over one year. I had a job where I commuted the same stretch of highway every day. For the first few years, every May/June the windshield was always badly crusted with bugs. Then suddenly one year, no bugs. Same car.

What year? Would love to have that data point, or an aproximation.

Yeah but what about the year after?

I mentioned this in a similar discussion on HN a few years ago. I used to own a Nissan Cube (a boxy car), and it would regularly get encrusted with insects every summer, when compared to other family members’ vehicles which did not.

Insects still get hit with aerodynamic cars, but the blows are glancing and less likely to cause a “burst”.

It's not like we were all driving in Chevrolet Bel Airs in the 90s and now switched to Lamborghinis.

My intuition for aerodynamics must not be as good as yours. But looking at https://caradvise.com/blog/2019/08/17/most-popular-cars-in-t... and https://www.caranddriver.com/news/g36005989/best-selling-car... is interesting. In particular, the way the headlights sit on the front of the car seems to have changed a lot. Cars in the 90s look to have lights that pointed straight ahead. That seems to have evolved over time to a more streamlined position and orientation.

It's mind-boggling how many trucks and SUVs this country owns...

It is an variable that very obviously needs to be controlled and is worth mentioning.

Yup, not only that, but the Lamborghini Countach has a Cd of 0.42, while every car on this list has a lower Cd, except for the original VW Beetle [1].

(Although, TBF, the Lambo's wing and aero package adds a lot of drag in exchange for much greater downforce)

[1] https://ecomodder.com/wiki/Vehicle_Coefficient_of_Drag_List

The studies for this are scarce, but this is curious and counterintuitive:

"The research also found that modern cars, with a more aerodynamic body shape, killed more insects than boxier vintage cars up to 70 years old."

https://en.wikipedia.org/wiki/Windshield_phenomenon

Are they, though? So many trucks, SUVs, and other cars that don't have sloping windshields. Also, I would expect even pastier windshields given that the nationwide speed limit was 65mph until 1995, and it took years for states to nudge it upwards to where it is now (85mph at some places in Texas).

Source: https://en.wikipedia.org/wiki/National_Maximum_Speed_Law

It also depends on the bugs spawning behavior. There are still species which blot out the sky when they spawn along the Mississippi.

I feel like this is something we could check with simulations. Given the same insect clouds, would an older car hit more of them than a newer one?