The screwworm was a genuine native of Central america and the southern us. So is it really accurate to say its invading, rather than it is returning? I cannot think of any other species labeled as invasive in its own native range. And people seem to have no qualms about wiping them out in the name of protecting livestock. Wiping out a wild species to protect livestock, sounds awfully similar to what happened to megafaunal carnivores.
I have a feeling you don’t have to worry about completely wiping out this species.
And I’ve heard of Imperata cylindrica being called “invasive” in its native areas.
It doesn’t meet the usual definition of invasive in the US since it once was distributed in the southern states before control measures eliminated it. But because of its impact to livestock, other warm-blooded animals, and occasionally humans, it is a species that warrants eradication wherever it’s a threat. I won’t mourn its elimination from any region and I doubt that it’s in any danger of extinction.
It’s kind of ironic too. The method of reducing their population is to breed lots of males, sterilize them by irradiation, then release them in mass over areas of concern. Then the sterile males mate with wild females, producing no offspring and reducing their population back to negligible levels.
So they’ll never go extinct because we’ll keep breeding them for the next resurgence.
I hate to even think of how they breed them in captivity. Live hosts?
My dad used to do this for the USDA in Hawaii, but for fruit flies which were shipped to California.
Have you seen a screw worm infection? It’s horrifying and it’s painful the entire time. There are stories about the fly getting inside you and the maggots eating you alive. They infect all different kinds of mammals, and even birds on occasion. Furthermore, research suggests the screw worm has a lot of ecological redundancy and its extinction will not lead to any secondary extinction or significant ecological cascades.
Is this some kind of appeal to morality? Have you see how horiffic bear attacks are?
Hey folks, please stay focused on the topic. @insectilluminatigetshrekt is the purpose of your original post just about the “invasive” label? I don’t think this should turn into an argument about the relative morality of animal predation and parasitism.
Yeah. It is about the term invasive. And, on a secondary level, about if we should eradicate them. Can we no co exist with the screwworm like we do the bear and lion and wolf?
Animals being slowly eaten by parasites has always been a natural part of ecosystems, and being a parasite does not inherently make an animal invasive and deserving of eradication.
In addition, just because no species is likely to go extinct as a result of screwworm eradication doesn’t mean that we have the right to decide to drive them to extinction.
Given that the species is returning to areas it formerly occupied, there is no reason for it to be classified as invasive unless there is demonstrated harm to the ecosystem, and to my knowledge, there is no research on that.
I don’t know. I only read about the method in a news article about their recent emergence in Texas.
Regarding justifying their extenction, whether intentional or not, I would lean toward the pro side. The potential for harm, not just to livestock but also people, pets, and it sounds like any warm blooded host, sound tremendous.
The only way I see coexisting as likely would be if infection prevention was made incredibly easy. Like flea prevention for pets, but it would have to be applied across all host vectors. That alone seems incredibly difficult, and would only help if people actually made use of the preventative for themselves, pets, livestock, or other domestic animals.
I personally don’t think the term “invasive” should ever be applied to native species, but government agencies often apply it to agricultural pests, regardless of whether they are native.
The question of whether screw worm should be extirpated from large parts of it’s native range is a more complicated one. No one seems to be worried about driving viruses that cause diseases like polio or smallpox to extinction, and viruses are a natural part of Earth’s biodiversity too. From an absolute purist environmental viewpoint, no species should be wiped out, but there are some that are unlikely to ever find passionate defenders.
It also becomes a question of what the alternative course of action is. Livestock owners are not just going to let it destroy their herds. Are we talking about a choice between releasing sterile males that wipe one species out, vs. spraying thousands of acres of pastureland with massive amounts of insecticides that wipe many species out? If so, it may be the lesser of two evils.
I personally would consider screw worms to be native, just like how Pere David’s deer went locally extinct in China and were re-introduced a century later. I was very fortunate and happy to see a wild herd of these deer in Yancheng! And even more so than Pere David’s deer, we certainly cannot reasonably consider screw worms to be an introduced species, considering they naturally spread to the USA without anthropogenic means.
Not just viruses, but serious attempts have been made at eradicating yaws (a bacterial disease) and guinea worm and hookworm (nematode worms). On the other side of what you said–a while back, while I was looking up if any organisms eat viruses as a food source, I learned that viruses play an important part in maintaining levels of organic matter in the oceans!
From an anthropocentric perspective–which, as a person, is a viewpoint I privilege–the difference between screw worms and other parasites, and large predators such as bears and wolves, is that I can take reasonable and effective steps to avoid being attacked by a large predator. For instance, a few years ago I was driving through Yukon and there was a brown bear and her cub standing in the middle of the road. Not being sure what to do, I simply parked my car until the bears finished crossing the road. People also take other anti-bear measures such as storing camping food in special manners, and walking away from bears. As an aside–I do consider it quite unfortunate how some people support culling of all wolves (or other large predators) in their country. Meanwhile, you can get a screw worm infestation by…sitting outside on your porch. You can get a guinea worm infestation by drinking water that hasn’t been adequately treated. You can get a hookworm infection by walking around outside barefoot. The ease of avoiding a bear vs avoiding screw worm seems quite substantial.
That being said, I just spent 30 minutes reading about conservation-induced extinction of parasites specific to a single host, and I think those arguments regarding parasites providing us ecological information and preventing infestation by more harmful generalist parasites or causing greater genetic diversity in the host may have some merit.
It helps to not have any open wounds.
Sure, but do you expect people to stay inside until any random little scratch is healed? What about pets, or livestock? For them, that would be cruel to force them to stay inside, more so for pets who have been trained to defecate outdoors and know it’s bad to go inside.
When we went to the Dead Sea, we were warned that if we had any open cuts, it would hurt quite a lot due to the high salinity of the water. I’m sure I wasn’t the only one that day who learned she had a cut that she wasn’t aware of!
This article about screw worm in Honduras describes how one person got infected because he sat under a tree and he had skin cancer. Another woman had ulcers from hypertension and was the one sitting on her porch. Another woman apparently had the fly go up her nose to lay eggs. And there is a homeless man whose crutches slipped, he fell, and that provided the wound for the fly to lay eggs in.
Where I live, the gusano barrenador is an actual problem, not an abstract discussion. This state is either second or third in the country; it varies week by week in the epidemiological bulletin. We receive local guidance on how the flies look and how to keep our pets inside as much as possible and reminders to seek medical care immediately should we suspect we or our animals are affected.
Today in her morning conference the Presidenta announced a sterile fly production plant will open in Chiapas later this month, the operation of which will help combat this plague. I feel excited and hopeful about this, in the same way I feel about the advances against dengue.
Armchair philosophy is fun for those in the comfortable seats.
The viruses that are wiped out are typically ones that target almost entirely humans, not generalists that have other ecological effects, though.