The only thing I knew about wasps before this video
was that they are those flying insects that hover round picnics and sting people.
That was it. I assumed, naively,
that wasps had no useful role in the world's ecosystem.
So when someone from the Oregon Department of Agriculture
got in touch and said that they send out taxpayer-funded wasps...
I had some questions.
Like... why?
- This is pest control at a ecosystem-wide level.
There are hundreds of thousands of species of wasp
and only a handful of those actually sting people.
The vast, vast majority of them go about their entire life,
and you never see them or notice them.
- Around the turn of the century,
the brown marmorated stink bug arrived in the United States.
It's originally from East Asia,
but enough of them had been carried in accidentally by global trade
that a breeding population started and then exploded.
Those stink bugs are now found across most of the continent,
and they consume crops like apples, pears, hazelnuts and soybeans,
causing millions of dollars in damage every year.
- They are a generalist pest.
They feed on hundreds of different plant species,
and they have a great range of climatic conditions
that they're perfectly happy to live in.
Its populations have reproduced without anything to check it.
- So what you want is the stink bug’s natural enemy:
which is a particular type of wasp, that's being bred inside this chamber.
- Parasitoid wasps attack other insects
and lay their eggs inside of them to reproduce.
Sometimes that's an insect egg.
Sometimes they eat the insect alive, starting at the least vital organs first.
This is where the inspiration for the chest-burster from Alien came from.
We breed the stink bugs because the parasitoid wasps need them to reproduce in.
As many stink bug eggs as we have is about as many wasps as we can produce.
Last year we produced around 20,000,
and the year before that we produced around 17,000.
- And they are tiny! I didn’t realise until I got here and saw them
that you could get wasps that are only about a millimetre long.
They’re so delicate that the researchers can't use tweezers to move them around.
they have to gently suck them up through chiffon fabric
using the housing of a ballpoint pen.
But human intervention in ecosystems doesn't have a great history,
so my next question was: well,
how do they know what to release and where?
- Researchers from USDA and different universities
went to Asia to find out what attacks it in Asia,
and why is it not such a big problem there.
They brought Trissolcus japonicus back over to the United States
into quarantine facilities,
tested it on North American species to see if there were any that
we didn't test in Asia, that it could also attack.
Decades of work go into making sure
that the wasps that we're releasing are also safe.
If we give it brown marmorated stink bug eggs and any other stink bug,
it'll choose brown marmorated stink bug 95+% of the time.
But if you give it just another stink bug egg mass,
it will use it if there's no other choice.
So we were actually a little on the fence about
whether or not we wanted to release it.
And then it showed up anyways.
- After years and years of work, the wasps showed up anyway,
because every year, millions of flights land
and millions of shipping containers arrive at ports,
and it's not like those are sterile.
So, now that the fight is being set up out in the wild anyway:
why do they still breed and release these?
- The parasitoid wasp needs some time to catch up.
It's around a millimeter and a half long. It can't fly very far.
We can drive it a lot further than it can fly in a single year.
So we actually get those populations started
without having to fly across the entire state of Oregon.
Normally the growers reach out to the Department of Agriculture
and we go out to a site visit.
Not every site is suitable for these wasps.
They're actually nectar feeders and pollinators, so they actually do need other plants present.
They can provide permanent, long-lasting pest control for not just growers,
but the entire ecosystem.
These do not sting people.
I have worked with not only this wasp, but other wasps that are much larger than it
that are parasitoid wasps, and I have never been stung,
and I've been working on these for over a decade.