Program Item Details
TITLE: Meg McCluskie, Graduate Student, Biological Sciences, University of Lethbridge
SUBJECT: #108 Jefferson Community Pasture
SYNOPSIS: .
AUDIO: Download Audio (mp3 format)
TRANSCRIPT:
Intro: The last couple of years, southern Alberta especially has been plagued by grasshoppers. And that’s one of the first problems Ducks Unlimited ran into when it started reseeding native grasses into the sections it was trying to restore in the Jefferson Moraine. The grasshoppers devoured the new grass.
But spraying with traditional pesticides was not an option because these would harm other wildlife. Meg McCluskie is a graduate student working under Dr. Dan Johnson, a grasshopper specialist at the Agriculture Canada Research Station in Lethbridge and also an adjunct professor at the University there. Her research is based on finding a more natural solution to control grasshoppers by testing essential oils.
SFX: SOUND OF ATV COMING INTO RANGE
I joined Meg at the Jefferson Morraine study site near Cardston where we rode ATV’s to check pitfall traps for insects. With over 100 species of grasshoppers, it’s really only two-stripe and clearwing that cause problems for farmers.
Meg McCluskie
MG: So this is our other main pest species here at the site. That’s called a clear-winged grasshopper. There are three types of short-horned grasshoppers. There’s band wing, that’s what this one is. And then there’s Melanopline, they’re spur-throated which is what the two-striped is. And then there’s the slant face. And the slant face here, one of the one’s here is called club-horn. And it’s got really obvious clubs on its antennae, and it makes a nice little whirring sound in the grass. If you don’t know anything about snakes, you can sometimes think it’s a little rattlesnake. But this one here, the clear-winged...
CC: OOPS, IT’S ON ME…!
MM: It jumped back onto me.
CC: WE KEEP LOSING THESE GUYS.
MM: They’re hard to hold onto. As soon as they see the light, they just jump right out, even if you have them in your hand like that.
Anyway, the clear-winged have an obvious line on their tagmane that come down and form a V. The two stripe have that also so people sometimes confuse them. But the two-striped have really obvious lines on their pronotum or on the thorax. It goes head, thorax, abdomen, on the thorax, the grasshoppers have a shield, and that shield is called the pronotum, and on the pronotum on the two-striped you can see the two stripes and they run down pronotum and then down the wing to form a V.
But on the clear-winged the stripes aren’t on the pronotum, they’re just on the wings. And also the clear are also a lighter colour than the two-striped
CC: (WHIRRING) THERE GOES OUR BUDDY. THAT ONE YOU WERE JUST HOLDING, WHAT STAGE WAS IT AT?
MM: That was an adult. When you can see they have fully developed wings, they’re adult grasshoppers.
CC: THERE’S QUITE A DIFFERENCE IN THEIR SIZES.
MM: Yeah, the clear-winged is quite a bit smaller than the two -striped. The two-striped is the biggest one we’ll find here, the clear-winged is quite a bit smaller than that.
CC: WHERE ARE WE GOING NEXT?
MM: We’re going to go to our next pitfall site to see how many beetles and other little critters we’ve got in there.
SFX: ATV STARTS UP AND DRIVES OFF
Our morning was spent driving up and down the dry hills, the hot sun beating down on us and the view clouded by smoke blowing from the forest fires in the mountains not all that far away.
Finally, sitting in the shade of the few scrubby trees we could find, I had a chance to ask Meg about her research on essential oils
Meg McCluskie
MM: The treatments we’ve tried are basically plant extracts. Neem is one that has a lot of research, some on grasshoppers, some on other pests. There’s been quite a bit of research done on essential oils in terms of other insects, lots of beetles and flies, but nothing is known so far on their effects on Orthoptera grasshoppers. So what we’re doing is trying to test their effects in the field and see if we can control the grasshopper problem without wiping out all the grasshoppers but just controlling the population a bit.
CC: NOW THE WORK YOU’RE DOING IS ALSO GOING TO BE THE BASIS OF YOUR MASTERS THESIS. HOW HAVE YOU SET OUT THE RESEARCH HERE?
MM: What we’ve done here is we’ve looked for areas where there are high densities of grasshoppers. And then we’ve selected those areas and flagged them out and done treatments. So randomized treatments of the selected essential oils and name and sprayed them on. So we count the number of grasshoppers there are in an area and then spray the area, and then we go back and count and see if we’ve brought down the numbers of grasshoppers in the area.
CC: HOW WOULD THESE ESSENTIAL OILS AND THE NEME, HOW DO THEY ACTUALLY WORK?
MM: Well, the essential oils have shown so far in other studies on other types of insects that they either have anti-feedant or pesticidal properties. So sometimes they’ll just cause the insects to not eat. Or Neem has actually shown that if you spray it on grasshoppers when they’re in the younger stages, the juvenile stages, they won’t molt. So they eventually die because it interrupts their growth.
And as an anti-feedant, it’s the same thing. They’ll eat but at a slower rate. Or they’ll eat but they’ll die from the eating.
CC: WHAT IS NEEM?
MM: Neem is also an extract from the neem tree that I think is from Asia. It’s from the neem seed, they extract the oil. It’s obviously really low toxicity because people use it for a topical treatment for arthritis and I think people actually drink it in tea in Africa and Asia, so it’s obviously pretty low toxicitiy.
CC: WHAT ARE SOME OF THE CHALLENGES THAT YOU’VE FACED THIS YEAR?
MM: The challenges have been many. Weather of course is always a challenge. The grasshoppers were late this year because we had so much moisture and cooler temperatures in the early spring, but of course, we want to test our stuff on grasshoppers that are still in their nymph stages. But it’s been so hot that the grasshoppers have developed pretty quickly.
But beyond that, the equipment. We were spraying our essential oils mixed with water. And you can’t spray when you have 20 kilometer winds. And of course we’re in the chinook area so we always had 30 to 40 kilometer winds. And having winds and then the sprayers. We were spraying with ATV mounted sprayers. So everything that could go wrong would go wrong. We’d be missing a sprayer part when we came out or something is broken, or electrical problems with our connections. Or it’s too hot and the essential oils are so volatile that you spray them on and five minutes after you can’t even tell you’ve put them on the ground. Everything that could go wrong did go wrong.
CC: IS THAT A CONCERN. SOMETHING YOU MIGHT HAVE TO LOOK AT, IS GIVING THESE ESSENTIAL OILS SOME STAYING POWER?
MM: Yeah, so far we’ve tried mixing them with water and soap. But there are other ways to apply them. Mixing them with oil so that they stay on a bit longer. You can encapsulate in microcapsules oils or products and spray that on and the the capsule will then open when it comes in contact with something. So less of it will go off into the air. Hopefully, it will come into contact with a grasshopper and then open and go into its cuticle.
CC: YOU’RE DOING THIS THIS YEAR. WILL YOU HAVE TO DO IT AGAIN NEXT YEAR?
MM. Yeah this study was preliminary. What I’ll have to do now is go back to the lab and try some of these oil mixtures with the essential oils and also just do more tests of different types of oils. And just see which ones are most effective at the lowest cost.
Because what we’re hoping in the end is probably farmers on a large scale won’t choose to change to essential oils from pesticides. But some organic farmers would find this information useful as well as conservation groups like Ducks Unlimited. So basically, what I’ll do is try and find something in the lab that works and is effective. And I’ll try and rear grasshoppers and then test without as many variables. Like, I won’t have problems with my sprayer and also I won’t have weather to contend with and that sort of thing. I can do smaller tests and then bring this to the field again next summer with more knowledge.
CC: WE’VE BEEN OUT IN THE FIELD, AND YOU’VE BEEN SHOWING ME SOME OF THE DIFFERENT GRASSHOPPERS, AND NOT ALL OF THEM ARE PEST SPECIES. WOULD THESE ESSENTIAL OILS KILL ALL OF THEM OR ARE YOU LOOKING FOR SOMETHING THAT WOULD JUST TARGET THE ONES YOU DON’T WANT AROUND? HOW WOULD THAT WORK?
MM: Well at this site the majority of what we see are the two species, the two stripe and the clear wing. The largest numbers we’ll have a negative effect on will be those grasshoppers. But, we don’t have at this point, we can’t say we’re just going to target the clearwing and the two stripe. That would be a miracle. Right now, that would be great, that would be way beyond even my PhD. But no, at this point, we’re just trying to blanket with what would have a negative effect on grasshoppers.
But we’re not even sure if the essential oils will kill the grasshoppers. If they just slow them down, that would be kind of what we’re looking for. But if we are able to kill the grasshoppers with essential oils, the percentage of the population that we kill probably wouldn’t be near even 50 percent.
What we want is to control the population. We want to bring the numbers down. We don’t want to wipe out the population.
THANK YOU VERY MUCH, MEG.
Thank you.
Meg McCluskie is a graduate student in biological sciences at the University of Lethbridge. We were visiting her study site at the Jefferson Community Pasture.
Interview starts at 16:39
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