So the next topic in agriculture that will talk about it is our use of pesticides.
We'll talk about them, thinking about chemical pesticides,
which is what you see in this picture, as well as more natural pesticides and deterrents.
So pesticides is actually a whole group of different chemicals. This includes fungicides, so things that would kill mold and other fungi.
Insecticides which is for the most part what people think of, so killing insects that are eating our plants. Herbicides,
so these are killing herbs, or more specifically killing different weeds.
Molluscisides killing mollusks, rodenticides killing rats, and there's tons of them. So when I say pesticides,
it's really a whole class of pesticides,
it's not just a one organism or one organism being targeted. So,
why do we use pesticides in the first place? Well as the name of it suggests, it's killing pests.
It's killing things that are affecting our crops.
So in these pictures you can see these are caterpillars that are feeding on these worms, err- these are caterpillars feeding on this
plants, so on these different leaves. And then here we have another caterpillar or a worm feeding on this corn. And
so by having pests, like these insects,
we are losing crops.
So pesticides is helping to improve our crop yields, so the amount of crops that we're getting.
This is really the major reason why it's used. If you can increase the crop yield, especially if you're a farmer,
this is increasing the amount of money you can make.
It also helps with deterring diseases, so if you think about insects such as mosquitoes that pass disease --
these are organisms we don't want around. I know where I grew up, so I grew up in Virginia Beach,
which is a really hot and humid place,
mosquitoes love it.
We actually have trucks that come around in our neighborhoods and spray out
pesticides in order to kill mosquitoes because they can spread all sorts of diseases, malaria, not so much here in the United States
but elsewhere.
Yellow fever, West Nile,
there's quite a few diseases that are spread that
affect us. Lyme disease is spread by ticks.
So not only can it help farmers, which is what our unit's talking about, but they are beneficial for other human health reasons.
But what's the downside though? It come, it comes at a cost. So one thing that happens is making of super pests.
And what super pests means is that these organisms are disease resistant. So for example, I'm going to kind of give you a scenario.
You know, here I have,
let's say this is a
mosquito, you know I got a writing tablet, but it's really not helping with my drawing.
All right, here's a mosquito and let's say there are
thousands of them and they could be
potentially carrying a
disease that can affect humans, and we developed a pesticide that kills it.
But there's a whole ton of mosquitoes. They have different genes, some of them will survive, so let's, let's say
99.9% of all mosquitoes die. Well that means
0.1%
lived and they lived because they had some sort of genes, some sort of genetics that helped them to survive.
They had some sort of trait that is helping them to survive.
So these organisms, this 0.1%, have now lived and
they are resistant to this disease. So they live,
they're going to get together and reproduce and make little, little baby mosquitoes that are also
resistant to that pesticide. So that means we have to make another pesticide.
This is the same exact issue that you may have heard about super bacteria.
So in our healthcare system, we're having the same problem.
Where we can kill 99.9%
of bacteria, which is all good and great,
but that 0.1% that lived, well they can spread and now they're resistant to that antibiotic
meaning you have to develop something new. So this is an issue in tons of different fields not just agriculture.
So,
this is a pretty big problem. There's
275 weeds, so these would be things like you see in this picture, so things that can over crowd our crops and
500 insects that are resistant to at least one pesticide. So these would be super weeds or super bugs and
this has been just increasing.
This is five times larger, this number, five times larger than it was 50 years ago. And
it's just because this is happening over and over again. Sure they're resistant to this, well ----
they're resistant to something, they start breeding, the best ones of reproducing we spray them with another
pesticide, it kills most of them, some live, those breed, those reproduce, and this cycle is
pretty much never-ending. It continues until we're like I can't think of another pesticide to kill these.
Another downside is most insecticides,
it is not all, I really want to emphasize that, but most insecticides will affect more than one insect.
You know, it might of just been worms on your corn that you're trying to kill but
that's not all you killed, you ended up killing a whole bunch of other organisms as well.
So for example a honeybees.
You may have heard of colony collapse disorder,
so I'll write that out for you. So colony, because bees are found in colonies, those colonies were collapsing,
disorder.
And one of the major reasons why were due to pesticide use. That some pesticides, again not all of them,
but some pesticides that were used or very broad. And
farmers don't want to hurt the honeybees and the honeybees are actually helping the farmers, not only because they're making honey
but they're pollinating those crops and helping them to grow.
But those pesticides were killing the bees and causing a huge loss in our bee populations.
Now wasn't just pesticides,
but pesticides was a major cause especially
in these states. These states that have a whole bunch of farming. We were seeing a lot of loss of our honeybees.
Pesticides can also kill natural predators.
So one natural pesticides can kill things that we need for example honey bees, but they can also kill the natural predators of those
organisms. So here, this organism, is
the tomato
horn worm.
Although it's called a worm, it is a butterfly or might be a moth, but it actually does grow into something. And
by the name it loves tomatoes. Now,
they actually have a really cool predator, and the predator is actually a parasite. So what you're seeing, all of this white stuff,
these are actually all eggs, and they're eggs from a wasp.
This wasp
literally like stings this hornworm
and then lays a bunch of eggs internally and the eggs grow externally and feed off of the worm
and then out come more wasps. These are wasps that won't harm
you, there are pretty small wasps, but they're only harming this pest. Well if you're using a pesticide,
that pesticide
could probably affect that wasp because that wasp is in close interaction with this hornworm.
So now you're getting rid of an ecosystem service, not only
did you get rid of horn worm, but it's natural predator,
which means in the future you're gonna have to use even more pesticides because all of
the
natural predators, all those natural wasps, are dead. So it's kind of like this never ending cycle, same with the super pests.
Now I want you to go ahead and pause here. There's a really cool video on this tomato hornworm, and the parasitic
wasp that infects it and you can kind of see how it really affects the hornworm and again something we would want to protect. We
want to protect this predator because it's a natural way to
fight these caterpillars for example. So go ahead and pause now and watch the video that should be popping up now.
Also, answer the follow-up questions in the weekly guide before resuming.
Another downside is directly related to humans, not the ecosystem.
Pesticides are dangerous. In all pictures that you look up of like pesticides and farm
people are in suits like these. I don't know about you, but if I have to wear a suit like this
that's because I am working with something dangerous.
Like in a science lab you wear suits like a lab coat, but these guys are wearing full suits. They have got gloves,
they've got face masks, they've got hoods, they're completely covered. That should tell you something about how dangerous these pesticides are.
But we're spraying them on our crops,
but ok.
So just to the people
that interact with pesticides, whether it's their job or whether it's your home pesticides using at your house, well 3 million people
get sick from pesticides. Now, this is pesticides working directly with it,
this is not you're eating a vegetable or a fruit that has pesticides on it.
Of those 3 million people who are getting sick about one in 15 actually die from that pesticide exposure.
This is mainly people who are working in
fields and farms like you see in this picture. Though, it could happen at home as well, but typically on farms
they have a much higher grade pesticide than what's sold to the general public, but still even if you may not die
someone is dying from the use of this pesticide, which is kind of scary to think about it, and then we eat it. A
particular pesticide that I wanted to talk about because maybe you're familiar with it is Agent Orange.
Agent Orange was used during the Vietnam War, and if you don't know much about Vietnam, it is very
foliage, there's a lot of foliage, so very, very dense forests. And
the locals knew those forests, they knew how to get resources from it, they knew how to hide in it,
they knew how to attack in it. So what we did, we is in the United States,
we developed a pesticide that would kill the forest. So they dropped it from planes and that would kill all the trees,
therefore reducing the cover of locals.
So a pesticide, now this pesticide wasn't used in our farms, is only used in warfare.
This is a very dangerous pesticide, it didn't just kill trees it killed people.
It burned people, so this was a general in the Vietnam Army, you can see here's a picture of him,
this is what he looked like.
Because he was in the forest when Agent Orange was dropped, and it caused such severe burns all over his body.
So pretty dangerous chemical.
Not only that, not only burns like this,
but it also caused a lot of birth defects so people that were exposed to it,
when it was still in their bloodstream, it still remained in their body, when they gave birth their children
had birth defects like you see in this picture. So
even though this lady, you know appears to look normal and could be
probably be pretty healthy, she may have been exposed to Agent Orange which remained in her body
and then when she got pregnant that Agent Orange affected the fetus. The fetus is
really, really small. So even just a little bit of Agent Orange
had a huge effect on the development of her children. And it wasn't just this family,
it was families all over Vietnam that were exposed to this.
So this is a very extreme case of a pesticide that was dangerous to humans.
We don't work with something like this in our fields, but we
still do work with pretty dangerous chemicals.
Another really important pesticide which we did use everywhere was DDT.
DDT was used in everything. Not only was it used in fields, it was used in people's yards,
it was used to around the house, it was used on you. This would be like spraying,
what is it like, it's skin stations, or whatever, like a bug spray on you. It was used in every single application.
It was everywhere, and it's actually good because this one didn't harm humans,
so it wasn't like Agent Orange, which is calling huge birth defects, but it did have a pretty big effect on birds.
So,
with our bird species, let me go back,
we talked about it a little bit when talking about endangered species.
Remember the bald eagle, the peregrine falcon, the brown pelican, all really important species,
they were going endangered because the build-up of DDT.
This DDT was getting into those birds and
when they laid their eggs, their eggs were soft, and the eggs broke open and
reproduction was way down.
So it was really, really important to these
to environmentalists and really to our ecosystems that DDT was banned
because of all these negative effects it had on our
ecosystems.
