Agriculture officials in Mexico are currently dealing with a horde of flesh-eating parasites.
The New World screwworm is a fly whose larvae burrow into the skin of animals like cattle, sheep and deer — often doing serious harm in the process.
Screwworm cases have been confirmed less than 100 miles from the southern border. Should they reach Texas, the flies could cause serious economic problems for industries like hunting and ranching, which is why the federal government is spending millions to try to push them back from the border.
Tracy Tomascik, associate director of the Texas Farm Bureau responsible for livestock and animal health, spoke to Texas Standard about the progress those efforts have made. Listen to the interview in the player above or read the transcript below.
This transcript has been edited lightly for clarity:
Texas Standard: What kind of impact are these screwworms having right now in Mexico and Central America? Could you say more about that?
Tracy Tomascik: Yes, unfortunately, they’re having a devastating impact on animal health and the productivity of the farms and ranches in those areas.
The population of those fertile wild New World screwworm flies has just grown and festered in the central part of Mexico and also Central American countries over the last couple of years.
The things they’ve done in Mexico to help mitigate the increase in those populations have slowed it down, but certainly have not stopped it.
So folks understand what’s at stake here in Texas for ranchers, for agriculture, could you give us a sense of what this means if the screwworm does, in fact, come into Texas?
Yes, the estimates that we project would be well over $8.5 billion from a livestock standpoint.
Boots-on-the-ground impact is going to be much more consistent and constant evaluation, physically walking up to or being next to your livestock — whether it’s goats, cattle, horses, pigs — and examining those animals for wounds that have been infested with a New World screwworm fly… It’s the time and effort that really adds up.
It’s my understanding that part of the U.S. strategy to keep them out of Texas and some of the southern states involves dropping screwworms out of airplanes. What’s that about?
Yeah, it’s actually a decades-old technique and response. Those flies that they’re dropping out are sterilized.
And the unique thing about this particular species, the screwworm fly, is the females only mate one time in their life cycle. So if they mate with a male that’s sterilized, they’ll only have unfertilized eggs and therefore those eggs won’t hatch, ultimately breaking the life cycle.
How long are these operations going to go on?
This is a very long-term operation. Right now, we’re working as fast as possible to increase the production capacity of these sterile flies.
And if you think back into the last time that we had a long-term response for New World screwworm in an eradication effort, it was the ’50s, ’60s, and even the ’70s. So we’ve got what could be a decades-long operation to move these flies from the Texas border all the way back down to Panama with the Darién Gap.
Tracy, is it reasonable to assume that at some point screwworms are going to reach the U.S. border, that it’s just inevitable, or is this something that can actually be prevented altogether in your opinion?
I think that we’re on the cusp of turning this thing or this population back. And when I say “on the cusp,” we have to think about the timeline that we’ve endured.
A year ago, all the models said that we would have screwworm flies in Texas. But the work with our federal partners and then the Mexican government and the Mexican ranchers, has prolonged that and given us time to start the construction of another sterile fly facility in Texas, to improve and enhance our distribution techniques of those sterile flies, and ultimately make the modeling better of where we anticipate those flies to move next and at a much slower rate.
So, yes, we are prepared for an infestation to occur in Texas. But I think, and we have a proven track record of delaying that. And we’ve done extremely well with the strategy that’s in place so far.
So I think the takeaway here is that when we do get one in Texas, we are prepared to respond quickly and we will be able to limit, severely limit, the movement of those flies once they get into the United States in a way we haven’t seen before.
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