insects

WTF Fun Fact 13443 – Dead Fruit Flies

When fruit flies see or smell their dead comrades, their own lives are cut short. Talk about putting a damper on your day!

Fruit flies stress after seeing other dead fruit flies

If you’re a fruit fly, seeing one of your fallen is not just unsettling. It’s downright harmful to your health. Despite their diminutive size, experience stress and negative health effects when they witness the remains of their kin.

Neuroscientists have found that when fruit flies (Drosophila melanogaster) see their deceased fellow flies, specific brain cells are triggered.

And these aren’t just any brain cells. They are neurons that respond to visual stimuli, known as visual projection neurons (VPNs). These cells relay information from the flies’ eyes to their brains, helping them interpret and react to what they see.

What’s going on in a fruit fly’s brain?

But let’s add a pinch of intrigue to the mix. These neuroscientists didn’t stop at merely identifying the type of neurons involved. They zeroed in on the specific group of neurons that reacts to the sight of dead flies. The neurons in question are part of a cluster known as the “globus pallidus.” This is an area associated with movement and learning.

These scientists have discovered the precise neighborhood in the fruit fly’s brain where the “dead fly sighting stress response” takes place.

So, what happens when these neurons fire? In short, they trigger a series of stress responses that have a tangible impact on the fruit flies’ health and lifespan. As the sight of a dead fellow fly becomes ingrained in the fly’s brain, it alters the expression of stress-related genes, tipping the physiological balance and leading to a shorter lifespan.

This discovery has raised intriguing questions about the evolution of empathy and social responses in insects. While fruit flies may not experience empathy in the way humans do, their stress response to seeing dead comrades suggests a level of social awareness. This raises the question: why would such a response evolve? One possibility is that the sight of death serves as a warning signal, indicating the presence of potential threats or diseases, thus prompting the fly to modify its behavior.

However, this remarkable finding does more than just throw light on fruit flies’ stress responses. It could also contribute to our understanding of how human brains process stress and trauma. Humans, like fruit flies, have neurons that respond to visual stimuli. Therefore, these findings could lead to a better understanding of how our brains respond to stressful visual experiences, and potentially inform treatments for stress-related disorders.

— WTF fun facts

Source: “Seeing dead fruit flies is bad for the health of fruit flies – and neuroscientists have identified the exact brain cells responsible” — The Conversation

WTF Fun Fact 13143 – Grass Screams When Cut

You’ll never cut your grass again without thinking of this weird fact – grass cries for help when it’s mowed. No, you can’t hear it, but scientists have discovered grass screams when cut.

How does grass scream when cut?

We’re only just beginning to understand how plants communicate with one another and the rest of the world around them (including insects).

Dr. Michael Kolomiets, a Texas A&M AgriLife Research plant pathologist, published an article in 2014 in The Plant Journal noting that the aroma of cut grass is the plant’s way of both signaling distress and attracting beneficial insects that will help it heal.

According to ScienceDaily (cited below): “When there is need for protection, the plant signals the environment via the emission of volatile organic compounds, which are recognized as a feeding queue for parasitic wasps to come to the plant that is being eaten and lay eggs in the pest insect,” Kolomiets said.

Plant communication

Grass produces a “defensive” protein when damaged. Of course, that doesn’t stop the lawnmower or insects from destroying the blades. But it appears to produce a compound that repels insects that are feeding on the damaged grass.

This compound, or one related to it, also appears to attract organisms like parasitic wasps that feed on insects like caterpillars that are destroying the grass.

Or to put it in science-speak:

“We have proven that when you delete these volatiles, parasitic wasps are no longer attracted to that plant,even when an insect chews on the leaf. So this volatile is required to attract parasitoids. We have provided genetic evidence that green leafy volatiles have this dual function — in the plant they activate production of insecticidal compounds, but also they have indirect defense capability because they send an SOS-type signal that results in attraction of parasitic wasps.”

So, maybe it’s not so much that grass screams when cut so much as it cries for help. Either way, freshly cut grass emits a compound that repels damaging insects and attracts insects with a protective function.

It’s just one of the many ways that plants are far more complex than we had ever previously imagined. — WTF fun facts

Source: “Mown grass smell sends SOS for help in resisting insect attacks” — ScienceDaily

WTF Fun Fact 12725 – Ancient Stone Pillows

It’s hard to find a good pillow. And while some of us like our pillow firm, it would take a major adjustment to sleep like ancient Mesopotamians and Egyptians (well, in more ways than one, I suppose).

Here’s one of the most famous pillows in history, brought to you from Egypt King Tut’s tomb:

One of 8 headrests found in Tutankhamun’s tomb. The god of air, Shu, is carved in ivory. The piece resides in the Egyptian Museum in Cairo.

It’s beautiful, but it lacks the kind of functionality we typically look for today.

Until the Industrial Revolution, pillows weren’t even a household object. Yes, some ancient Greeks and Romans did stuff straw in cloth to lay their heads on, but a pillow is also a symbol of having excess lying around to use for more practical purposes. However, we can credit the Greeks with bringing us closer to the era of the soft pillow.

However, in ancient Mesopotamia, China, and Egypt, wealthy people would elevate their heads on “pillow” made of stone (or ivory – or another luxury material). They were designed to keep insects out of their ears, noses, and mouths – and probably to maintain a good hairstyle every now and then.

We’ve also found some pillows that are beautifully engraved with messages about keeping away bad spirits as well, but it’s unclear how those would be fooled by an elevated head. Still, it gives us a good idea of what ancient people were concerned about when they laid down their heads at night. — WTF fun facts

Source: “HEADRESTS IN GLENCAIRN’S EGYPTIAN COLLECTION: PRACTICALITY AND PROTECTION” — Glencairn Museum