The new world screwworm, which is actually the larva of a species of fly, ravaged the Texas cattle industry for much of the 20th century until it was brought under control in the late 60s. The USDA had declared the fly eradicated in the US, until June 3rd of this year when the larva was found on a calf in Zavala County.
Now there are more than 20 cases in Texas, mostly reported in cattle and sheep. State and federal agencies have instituted quarantine measures and released millions of sterilized flies to combat the spread.
The Waco based Texas Farm Bureau has been an important part of educating farmers, ranchers and the general public about the outbreak. Communications Director Gary Joiner joined JB Smith on Friday Forum this week to talk about the screwworm and the threat it poses to McLennan County.
This transcript has been edited lightly for clarity:
JB Smith: I wonder from your perspective what the general reaction among livestock producers and the general public has been. Are we freaking out or are we not taking it seriously enough?
I think the right way to describe it is it is not time to panic, but it's time to prepare and it's time to be proactive. This is a situation that maybe two or three generations of Texans have never experienced, but you talk to someone who's 70-75 years old, they remember some screwworms not only in the livestock and wildlife community, but maybe on their personal pets when they were growing up.
We never thought we'd be back in this situation again, but here we are. The good news is we beat the screwworm then and we can beat it now. We have better tools, better technology. I think the farm and ranch community is better prepared and I think more able to deal with this, manage it before it becomes a widespread infestation.
JB: I do wonder how quickly you think we could see the screwworm here in McLennan county, in Central Texas?
Entomologists right now are studying those movements and are really saying that the fly itself does not travel great distances. The fly itself may travel six miles in its lifetime, and a fly may only live 30 days or so in total. What's happening is a fly can travel 75 miles per hour because it's in a trailer. It's on an animal. It's human movement that's bringing those flies to areas of the state in natural migration of the fly may not have brought it to. So that's where we're talking to farmers and ranchers now. I've been in meetings with a thousand farmers and ranchers in the last week wanting to know about new world screwworm. And the word is be vigilant, be proactive. The best thing you can put on your animals right now is your eyes. Look at them every day. If you can, look at them as often as possible. And if you see something, say something.
Right now, we’ve got nearly 20 cases in Texas in which an infestation has been confirmed. But it's been an individual infestation. It's not been a widespread occurrence. And those are being individually managed. And those animals are recovering, they're surviving. And the proactive nature of those that reported – that calf, that goat, that sheep, that dog – they're the ones that are really stepping up and making a difference because if they let their veterinarian know, let the animal health officials know, then we've got the tools to go in and stomp it, defeat their life cycle, and we're done and we're through with that infestation.
Around here we have a lot of people who just run some cows back on the back 40 or whatever. What kind of symptoms do they need to be looking for?
You're looking for changes in behavior. You're looking for an animal that's showing stress. They're shaking its head, they look swollen, they have lost their normal appetite. There's something that's causing them to feel poorly. There may be a wound. Even if something as small as a tick bite is enough for a screwworm fly to lay the eggs to begin that cycle of infestation. So any kind of open wound, any type of cut, any kind of abrasion, particularly when a new animal is born in the cattle cycle. When you have a new calf on the ground, there's an umbilical cord in an area that is extremely vulnerable. And new world screw worm flies target those type of early births. White tail fawns, when they're born, when they have that umbilical area and that soft area after being born. That is sometimes the location in which new world screwworms are first to attack.
Now, you mentioned wildlife. I understand that this can also be a threat to pets.
Exactly. Any mammal, including some birds, are vulnerable to New World screwworm.
What's different about this fly?
There are many flies that feed on decaying tissue, on dead animals. This is a fly and a larva that it produces that needs live animal tissue. So they're looking for mammals that are vulnerable that have a wound in which the female fly can lay its eggs. Up to 200 eggs can be laid in that wound. And then, those hatch within 12 to 24 hours into small larvae. And it's that larvae that begins to burrow into the tissue.
It's called screwworm because there's two little hooks on the front end of the head of that larva that begins to burrow into that live tissue. That's where you get your infection. That's where you get your large wound, sometimes fatal, but you can treat that wound. And we have tools now, some under an emergency basis, some tools that we've had for a while that can eradicate those larvae, kill those, you can collect those samples, and then you can help the animal health community determine if indeed those are screwworm larvae. And if we do, we've got sterile flies to drop. We've got other tools to circle that lone infestation and prevent it from becoming a broader infestation in a larger area.
So it's good to know it's not a death sentence.
It is not. It is not. All the animals that so far have been identified as having a screwworm infestation have been treated. They have survived. The proactive nature of those livestock producers helps save those animals, and it's manageable if we get to it early.
I've read that experts say we need to produce about 400 to 500 million sterile flies per week to roll back this threat. Right now, apparently, we can produce about 100 million. And there is production ramping up in a couple of places, but it's going to take several years to get up to that 500 million. How optimistic are you about expediting that effort? Or do you think that prevention methods could contain it?
It's going to be a combination of what we have at our disposal right now and what we know is coming when a new infestation is located. There is an immediate dispersal of about 4 million sterile flies to that immediate area – on that premises, on that farm, on that ranch – and that is taking care of that outbreak. [The goal is] to blanket that area of Texas to create a biological wall from those sterile flies to continue to do the work and push those natural populations back.
You're going to need 400 to 500 million flies a week to do that. That is not available right now. We have a production facility in Panama that's producing about 100 million. They're being flown to the Rio Grande Valley and then they're being utilized for dispersal both by air, by ground, and then by release traps that are put on private property. There is a second facility the United States has invested in that will soon be online and that will generate another 40 to 50 million flies a week, eventually to 100, but 40 and 50 [million] initially. So there's some more for us to use. But the big answer and the big solution is a facility that is under construction in the Rio Grande Valley right now.
That's the one in Edinburgh.
That's correct, Moore Air Base, which played a huge role in the 1960s and 70s in this effort. A new facility, a huge facility that is bigger than a Costco, that is like a biohazard rank 3. It's like an aircraft carrier, not a fishing boat. This is a large facility with heavy security measures that's under construction. We're hoping to have that completed by May of next year. And the sooner the better because those flies will fill in that gap that we're needing that we're short of right now. Until then, we're using things like AI, we're using new technology. Where do those flies need to be dispersed that we have? Where are the flies that are on the ground? The natural movement, where are they going? And we're trying to be very strategic, very targeted to use the flies that we have.
Is this having any effect so far on beef prices, which we can see it at the supermarket, are pretty high right now.
I can tell you that the nature of the outbreak was responsible for some higher beef prices because we shut the border to Mexico. When it was determined that Mexico had a movement of New World screwworm flies heading towards the United States, the U.S. department of Agriculture made a decision to close all ports of entry into, not only Texas, but the other border states for livestock from Mexico. So that reduced quite a bit of animals that would normally be in the beef production pipeline. As a result, because our livestock herd in our US is already at a 75 year low because of drought and other factors, limiting the number of animals coming from Mexico just made that supply even shorter.
It's important that the top line on this answer is it is not a food Safety issue. New World screwworm does not affect the meat of the animal. It does not impact any foods that we enjoy as American consumers. This is an animal health issue, a production issue that can be managed, but there are no food safety implications because of this pest. This is not a disease, it's not a virus, It's a pest, and that's what we're dealing with.
