The New World Screwworm is a parasitic fly whose larvae burrow into and consume live animal tissue, primarily affecting livestock in Texas and New Mexico; it is not a food safety risk for humans, and Iowa State University researchers are actively involved in containment efforts using the sterile fly program, which releases millions of sterile male flies to prevent reproduction and has successfully eradicated screwworms from the United States since the 1960s.
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Ask 9: Should I be worried about screwworms?
Added:[music] >> Good evening. Welcome back to Ask 9. I'm Becky Felts.
>> And I'm Jim Burton St. John joining us on a Friday. Hope you had a good week, a peaceful week after some severe weather that came through the area. Luckily, there's a chance for some storms, of course, on on Saturday. I know I know you talked to the weather people in regards to that, but it was a real nice day today.
>> Absolute. Sunday's going to be gorgeous.
>> Absolutely gorgeous.
>> in humidity is my favorite part, personally.
>> Absolutely. And for farmers, I mean, it's phenomenal because we now I mean, about a week, week and a half ago, we were at a deficit as far as rain.
>> Yeah.
>> Now we're actually at a surplus, we're in good shape, so area farmers are very happy.
>> Speaking of area farmers, actually Jim, excellent segue.
We are doing a more traditional question and answer format here on tonight's Ask 9. Iowa farmers recently got some guidance about something you have probably seen in the news, screwworms, which are a very kind of confusing name for this particular insect.
>> Yeah, I guess so. It The problem is is that as disgusting as it sounds, they they are like a fly for the most part that >> a fly.
>> that burrows into the skin of animals.
It feeds as a parasite actually on animal skin and it particularly is affecting livestock mostly south of the border in Mexico, but the problem is it has popped up in some cattle in Texas.
>> Yes, that is the larva form of this fly.
It ends up looking like a normal fly, but that larva is how it got its name.
And even though it's in Texas, the Iowa Department of Agriculture and Land Stewardship is keeping Iowa farmers updated on what they should know about this because Texas isn't really all that far away when it comes to an insect that can travel.
>> Well, the problem is is that it impacts our livestock, so then you automatically get concerned about, you know, the the the cattle market, the beef market, Americans food supply, the food chain.
And and so it can cause a panic. Also, when you hear about fact that this is a fly and a larva that feeds, you know, on on skin of animals, you start to worry if it's not an impact on human beings as well.
It is not.
>> That is the good news. Yes, they are saying that this is not a food safety risk. That's the general That would be the concern generally for most Iowans.
It is not a food safety risk. And the general guidance for farmers right now is if you are importing livestock, keep them quarantined. And otherwise, just keep an eye out on any like cuts or liaisons on your animals.
>> Lesions.
>> Lesions. Thank you, Jim. Um keep an eye and make sure those don't get infected by anything weird. And if it looks a little concerning, always always report that.
>> What I found [snorts] interesting, you know, when we were doing stories this past week, one of the interesting things that I found was was that it was basically eradicated way back in the 1960s.
It's always been a bit of a problem in Mexico, but in the United States, it had disappeared. And the other thing is when it comes to um Iowa, we're far enough north that if they can't eradicate it with chemicals or or some something like that, Mother Nature kind of takes care of it, too, because of our weather because of our cold winters. Um so so it really is an interesting problem that we're seeing right now. But once again, it's mostly what in Texas. Has it been reported in any other state? I know five pieces of livestock.
>> Fe is the other place.
>> Okay, so New Mexico as well. So basically along the border >> of of Mexico at this point. But there's always that concern that you know, cattle can sometimes be on the move. And so, you know, it it it it is it is something that it I guess it's good to know about it so that it can be taken care of right away and that there's transparency about it. But Iowa uh livestock uh uh farmers and and the people with the uh agriculture department are really stressing it's just not that big of an issue right now. It's more of a preventative keep it quarantined down there before it gets up here.
>> all educational. An interesting Iowa tie, Iowa researchers are some of the people who know the most about these screwworms and they had at one point been taking some of the screwworms to Iowa in a very contained way for the researchers to study. They decided that seems a little inefficient and also a little risky.
>> Somewhat.
>> So instead, they have taken a bunch of Iowa researchers down to Texas and they are down in Kerrville the Kerrville area of Texas working on getting rid of this current infestation down there. So we have Iowa folks, you know, right on top of this.
We're going to make sure we're all safe.
>> Literally on the front line.
>> Yes. I also talked with ISU Extension expert Dr. Grant Dewell and he is one of the people getting the some of that frontline communication about what's going on here and those guidelines. We are going to share that full interview that I shot with him earlier this week now.
Dr. again, thank you so much for joining us here today. First of all, I want to talk about what exactly a screwworm is because the name is a little bit misleading. So could you kind of share share a bit about that with us?
>> Sure. So yeah, the New World screwworm is basically it's a it's in the blowfly family um which is a uh a type of fly that typically lays eggs on uh tissue. Uh most blowflies lay their eggs on on dead tissue.
Um so if you you know, the the dead animal by the side of the road that is covered in flies and maggots, those would be typical blowflies and so um uh though then those eggs hatch and the larvae or the maggots would then consume the the carcass. The what's unique about the New World screwworm is the female fly doesn't lay her eggs on dead tissue. She lays it on live tissue uh and then those maggots then consume live tissue. So, it's a can be a pretty um devastating wound, particularly to young animals, uh having these larvae burrowing into the tissue. Um and and so they they call it a screwworm because it has the impression of this larvae digging down into the tissue, uh causing that.
>> So, how come you know, this is in uh Texas and New Mexico, but Iowa state is you know, still putting out some alerts about what animal producers here in Iowa should be aware of. Uh can you share some of those things that that Iowa producers maybe need to know right now?
>> Yeah, so the the main thing for our our Iowa livestock producers is to be vigilant uh and looking out for the for this pest.
Um it's uh you know, if everything goes right, um the USDA and the Texas Animal Health Commission will get it contained in Texas and and we won't have to worry about it up here.
Um but, we need to be prepared just in case, you know, things don't happen right and and and it escapes out of Texas and and starts to spread. So, um part of those is just being vigilant, uh keeping an eye on our livestock, uh making sure that we're not uh you know, we're looking at them, looking for these dental lesions. If you see a lesion on an animal that's got fly maggots in it, then that would be a reason to call your veterinarian, have them come out, uh take some samples and get them sent into the into the lab and make determine whether or not that's uh screwworm or not.
>> For any farmers who might be uh importing animals, what should they know?
>> Um so, generally our our import regulations haven't changed yet, uh really. Um so, uh unless those animals are coming out of the quarantine zone.
So, if if you were trying to import an uh animal from the quarantine area in Texas, uh that would require that the Texas Animal Health Commission uh inspects it and releases it out of the area.
And then the state veterinarian would have to agree to receive those. Uh so, there's a special permitting process for any that's in the quarantine area. But, if it's an animal that was in North Texas or Oklahoma or anywhere else, then we would be going under the same import regulations that we currently had last week as far as the whatever uh health in requirements that the state vet has uh to import those animals. So, uh nothing much has changed unless you're trying to get animals out of a quarantine zone.
>> The way that these screwworms are being um I I don't know if contained is the right word, but the defense against them I find pretty interesting. Are are you able to speak to those techniques at all, the way that the government is working to control it?
>> Yeah, so our our major control method um is is what we call the sterile fly program. Um and and uh again this the female screwworm fly um only mates once. Uh and then is able to go lay eggs when she finds a suitable uh lesion on an animal that she can lay her eggs in. So, so the fact that it that she only mates once gives us the opportunity that if we release a bunch of sterile male flies, uh then she's not able to actually produce from eggs that have been fertilized. And and so, um that's been the method um of controlling this this this fly for 60 70 years uh is is that sterile fly program. And so, currently right now, I think the USDA is releasing, you know, 4 to 6 million sterile flies a week uh around the area just trying to saturate that with with sterile flies. Uh you know, they also have uh a lot of of traps dispersed, I think like 8,000 traps which are baited with uh a attractant, which is basically a some form of blood smell uh that attracts the fly. And then they get stuck in the trap, and then they monitor those so regularly to see if if the fly is spreading beyond the containment zone. So, so we've got those traps spread out. They're they're uh releasing all these sterile flies.
Uh and that's the, you know, the main control mechanism. Then the other part is trying to identify any new cases that may be coming from either escaping the quarantine zone or from new excursions coming out of uh Mexico that may be getting across. Uh those would be what we're looking for with our traps. Uh and then having our livestock producers keeping an eye out animals looking for new lesions.
>> Dr. Doole, again, thank you so much for your time. Is there anything else I'm not thinking to ask that you think Iowans should know about?
>> Nope, I don't think so. I mean, it's it's not something we need to be alarmed about. It's something we need to recognize as it it is a risk. Uh and we just need to be vigilant in keeping an eye out making sure we're following those regulations so we don't want cattle moving without inspections or any livestock moving without an inspection so that we don't let, you know, the the fly is not going to travel that far the the way the organism is going to move is because somebody moved an animal out of the quarantine zone without it being inspected. So, we really need to make sure we're following those inspections and keeping movements controlled.
>> Again, that was Dr. Grant Duel from Iowa State University Extension. This is again not a food safety risk for the general public, and they are only concerned about it in a way that they are extra careful monitoring any importing of cattle.
>> And I think it's interesting once again that the plan solution to limit the impact of the screwworm flies is basically to introduce the fly population to male sterilized flies. A very natural way of doing this. We were talking earlier that, you know, you could bring in a predator, another insect that might go after the fly or whatever, then you may have a problem with that insect. So, this is a real makes a lot of sense to do it this way.
And And what's interesting is that this is the way they did it a long time ago.
In the 1950s when the screwworm was detected in Florida, that's what they did, and they kept doing it and drove it into just Mexico, and then drove it further south until about 2006 when it was eradicated throughout the United States and down to the Panamanian border. So, basically Central America and America by 2006 it had been eradicated through this method of of the mass use of these sterilized flies that take out the screwworm flies. It It It's ingenious, and it's sad that it sounds like that's exactly what has to be done all over again. What what worked before they believe will work again.
>> If it's not broke, you know, might as well give it a shot.
>> right.
>> It is a funny visual though. Dumping millions of flies and being like, here we go.
>> Yeah. Go at it, boys.
Oh, well.
>> Well, we I It'll be interesting to see how long it takes. I'm curious about the timeline a little bit, but And just have to see.
>> It is also interesting to see the the the the fact that I was so actively involved in this, not only as you were saying the ISU professors, but also the Ames Laboratory, which is used for uh so many different um problems that could come along, whether it is bird flu or any of these contagions that can can impact our food supply, that the labs in Ames is often one of the very first places that the government turns to in order to detect it and at least start the process of eliminating it.
>> Yeah, even though this has been gone for decades and decades, they were still ready just in case it came back like this.
>> Thanks so much for joining us for Ask Nine. We appreciate you joining us every Monday through Friday live at 5:30. And as always, if you have questions, message message Casey Hargie on Facebook, and you can always email us as well at Ask Nine.
>> Have a great evening.
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