They’re against science and free speech » « To boldly go where everyone has gone before

The nefarious prickly pear

I’ve always taken cactuses for granted — I’ve lived in deserts before, and they’re just there, growing all over the place, and familiar part of the landscape. I didn’t think about the fact that they’re an entirely American clade, or that they could be a destructive invasive species elsewhere. I didn’t know that they were a major pest in Australia, along with rabbits and cane toads (Australians keep bringing in alien species that devastate their ecologies, in desperate attempts to counter the previous wave of invaders). So this was an informative video for me.

It’s also an example of where bringing in yet-another-foreign species, in this case moths and scale insects, defeated the problematic invasive species. For now.

They’re against science and free speech » « To boldly go where everyone has gone before

Comments

  1. francesconic says

    We export alien species that devastate ecologies too. How are those fire prone Eucalypts doing in California ?

  2. raven says

    Prickly pears in South Africa
    From Wikipedia, the free encyclopedia

    In South Africa, many species of Opuntia are considered highly invasive including O. aurantiaca, O. elata, O. engelmannii, O. ficus-indica, O. humifusa, O. leucotricha, O. microdasys, O. monacantha, O. pubescens, O. robusta, O. salmiana, O. spinulifera, O. stricta and O. tomentosa. These species are classified as Category 1 invaders, and targeted for national eradication; most activities with regards to the species are prohibited (such as importing, propagating, introducing, translocating or trading).[1]

    Opuntia ficus-indica (known as the prickly pear) is a plant that has been part of the landscape of South Africa for over 250 years.[2][3]

    Arrival and spread
    The prickly pear was brought to South Africa, from the Americas, in the mid-18th century.[2] When it established itself in the Eastern Cape and Karoo, it took control of the environment around it because of being drought resistant, able to reproduce without seeds as well as its “extensive seed dispersal”.[5] It thrived in these regions, where the original vegetation had already been disturbed by settlers.[5]

    Uses
    Part of what facilitated the spread of the prickly pear was its utility. The plant was used by a variety of people: It has “been, at some time, of importance to white commercial farmers, farmworkers, African landholders and urban communities”.[6] The fruit can be eaten or turned into jams, preserves, beers, wines and soaps and the leaves can be used as medication.[7] In addition, prickly pear can be useful fodder, particularly during drought, when few other plants survive.
    and
    In 1932 biological control in the form of, particularly, the cochineal and phycitid moth, was introduced and was highly effective.[3] It is largely due to this that, in 2002, there was a tenth of the number of prickly pear left when compared with the 1930s.[16]

    They did the same thing in South Africa before they did it in Australia.

    Prickly Pear cactus was introduced into South Africa in the 1700s. It became an invasive species and took over many areas. They ended that problem in 1932 by introducing insect predators.

    I’ve eaten the fruits of Prickly Pears before, harvested from wild plants.
    They are very good.

  3. birgerjohansson says

    Hmm…the biggest invasive species from 1492 onwards has been Europeans. People descended from my country seem especially prone to become bigoted christians or far-right conservatives with destructive consequences for the land.
    (With exception for the guy who built the Monitor, he was great)

  4. says

    Whenever humans upset the balance in an ecosystem, it is always a disaster. The human mind is not capable of taking all the myriad of factors into account when they insert a new factor into an ecosystem. I’m sure that, a.i. modeled on the human mind, will also be incapable of meddling successfully with the incredible complexity of an ecosystem. Prime example of human hubris and folly: the deadly biosphere experiment in arizona.

  5. lasius says

    There may be one species that managed to get to the old world without human help. A species that conveniently spreads via birds.

    This is also something I always notice in movies and games that are set in the ancient Mediterranean world. They often show Opuntia cacti long before they would be introduced from America.

  6. robro says

    francesconic — Those Eucs are doing fine but they do like to fall down.

    It’s the Acacias that are the real bother when they flower in the Spring. I’ve never suffered from allergies, but when the little stand of Acacia next door to us bloomed this Spring, it hit me hard.

    Here’s one from the Marin County naturalist…yeah liberal bastions have those: She says that the Summer time browning of the hills in California is not natural. It’s the result of the native grasses being supplanted by invasive grasses from Europe to feed livestock. The native grasses were long rooted and would stay green all summer. We passed a little plot of native grasses the other day and they were as green as could be.

    Anyway, I think it’s all a product of colonialism.

  11. anthrosciguy says

    While waiting to disembark after a cruise to Japan, I met a guy I wished I’d had more of a chance to talk to. His job had been to go to the locales an invasive species was from and see if he could find anything there that would combat it without causing yet more problems. Fascinating and difficult job. He was a jolly fellow.

  12. Robbo says

    i was surprised years ago when i stumbled across a cactus while climbing in Blue Mounds state park in Minnesota.

    i didn’t realize they could survive here.

    Minnesota is home to three native cactus species: the brittle prickly pear (Opuntia fragilis), plains prickly pear (Opuntia polyacantha), and the rare ball cactus (Coryphantha vivipara)

  15. Hemidactylus says

    Maybe we could do an exchange. We take back prickly pears and in return the notorious Aussie pine and melaleuca are taken back. We no longer want them.

    Yeah I know it’s not a pine (preemptively in case a pesky pedant on a recent tear goes there):
    https://landscapeplants.oregonstate.edu/plants/casuarina-equisetifolia

    An evergreen tree that superficially resembles a conifer due to the production of cone-like fruits and pine-needle-like branchlets; it is not a pine… It has been widely distributed throughout the world and is often considered invasive. Some regard it as the most invasive species in south Florida where it was introduced in the 1880s. It is now one of the most common trees on frost-free beaches world-wide.

  16. Hemidactylus says

    Reginald Selkirk@13
    I guess we can rule out Neanderthals being happy motorcyclists. The Haaretz article was paywalled for me though a Google search got around that. Also here:
    https://archaeology.org/news/2026/06/09/did-early-humans-eat-bugs/
    Despite a local detractor, this is an interesting notion you segued into. Especially:

    Modern humans who lived close to the equator were found to be more likely to be able to digest bugs, but this ability decreased among modern humans as the distance from the tropics increased. The study indicates that modern humans in Europe and the colder areas of Asia had lost the ability to digest insects by about 9,000 years ago. “In the tropics, edible insect species can be harvested in large numbers without a lot of effort,” Piñero explained. “Thus, eating insects becomes an advantageous dietary practice, and their digestibility favored by natural selection,” he said. In addition, Neanderthals were found to carry the genes that would allow them to digest chitin, and one Denisovan genome in the study suggests that this human relative was also able to eat bugs.

    See also:

    https://www.science.org/doi/10.1126/sciadv.aec6939

    Abstract
    To meet the rising food demands of our growing population, the Food and Agriculture Organization proposed edible insects as sustainable sources of animal protein. Although hundreds of million people already consume insects around the tropics, western societies remain averse to entomophagy. To trace whether ancient Europeans consumed insects, we here apply two complementary genomic approaches. Metagenomic screening on 745 ancient anatomically modern human dental calculus returned limited insect DNA traces, with read abundances well below those observed in Neanderthals, western chimpanzees, and gorillas. In addition, genes encoding stomach-expressed chitinases show two of the most significant signatures of latitudinal differentiation genome-wide. Clines are consistent with evolutionary benefits of entomophagy in tropical regions and with expression quantitative trait locus data supporting low chitin digestibility in present-day Europeans. Ancient genomes confirm that both clines already existed at the onset of agriculture and persisted despite massive migrations. Together, our findings support occasional and possibly incidental insect consumption in Europe over the past ~9000 years.

    Yeah the lady who swallowed a fly joke has something about creating ever worsening new problems with attempted remedies for previous problems, but you shouldn’t have gotten dragged for adding an interesting aside.

  17. John Morales says

    Hemidactylus:

    but you shouldn’t have gotten dragged for adding an interesting aside.

    Dragged, eh?

    Zero relevance to the OP.

    Missed the very joke.

    Here, for you: https://en.wikipedia.org/wiki/Cane_toads_in_Australia

    (Third-party sniping is still sniping. How’s that working for you?)

    Despite a local detractor

    You are O so brave! Not in any way a local detractor, nosiree!

    Passive-aggressive indirectness is old hat to me.
    I am right here, you know.

    Cowardly and performative. Kinda cringe. But hey, it suits you.

    (Cheers!)

  18. John Morales says

    Maybe we could do an exchange. We take back prickly pears and in return the notorious Aussie pine and melaleuca are taken back. We no longer want them

    Nah. Chop them down all you want, in your own place.

    Go for it.

    No need for an exchange, is there?

    Asking for permission from Oz is cringe, too.

  19. Hemidactylus says

    My guess would be that Selkirk got the joke unbelievingdwindler made but was itching to mention differences in chitin digestibility in subsets of humans versus other apes instead. For that I’m thankful. Sadly my little joke about an invasive species exchange was taken literally (IOW not gotten). Whoosh.

  20. chigau (違う) says

    My first archaeology work was at a site called “Cactus Flower” (aka EbOp-16).
    We used wheelbarrows with inflatable tires for moving dirt. The cactus spines flattened the tires.

  21. John Morales says

    Hemidactylus, a kind guess. Motivated, but.
    I am quite familiar with Reginald, and his output.
    Much as Birger, a bit of a headline hunter.

    Sadly my little joke about an invasive species exchange was taken literally (IOW not gotten).

    <snicker>

    Sadly, my little joke about your little joke taken literally (IOW not gotten).

    (whoosh!)

  23. Hemidactylus says

    The aside about insect eating humans set up a little joke about Neanderthals not being happy motorcyclists. I guess that failed to land. Not gotten?

    Now Birger is getting dragged too I see.

  24. John Morales says

    The aside about insect eating humans set up a little joke about Neanderthals not being happy
    motorcyclists. I guess that failed to land. Not gotten?

    Um, attempted joke. Yes, gotten. I only have an ‘R’ license, so only a biker myself.

    It was featured on an episode of ‘Happy Days’ FWTW.

    Now Birger is getting dragged too I see.

    Nah. He’s a magpie. I’ve noted that many a time.

    Posts there, here, gathers shinys.

    You know the topic is invasive species, not fly-eating, right?

    Reginald saw that, figured that comparatively nobody really reads Lynna’s thread, so posted it here with the weakest of attempted justifications.

    You fancy yourself a white knight, I get it.
    Being feisty, I get it.

    But seriously, you are very close to making me stop; PZ has put a stricture upon me to not have fun with commenters, and you are really really trying me with your efforts.

    Heh. You really, really are out of your depth.

  26. John Morales says

    coffeepott, that’s silly.
    Chatbots have no need for hugs.

    Helpful little buggers, but: https://www.apsc.gov.au/initiatives-and-programs/workforce-information/research-analysis-and-publications/state-service/state-service-report-2024-25/ways-working-ai-aps/detecting-priority-weed-species-scale-drone-ai
    ↓
    Invasive weeds can have severe consequences for biodiversity and threatened species. Finding and treating weeds is costly and time-consuming when they have to be located and identified on foot. The Australian Government is supporting an AI project that provides a quicker, cheaper and more accurate solution to detecting and managing weed species.

    The Saving Native Species Program’s Threat Innovations grants were designed to encourage continued investment in longer-term actions to reduce pervasive threats at the landscape scale. In 2024, Climate Change, Energy, the Environment and Water awarded a grant under this program to the Centre for Invasive Species Solutions to pursue the WeedRemeed™ project.

    The project builds on existing WeedRemeed™ technology that uses a colour-picking mechanism to detect weeds. The upgrade includes AI-driven image analysis to improve accuracy and include a wider range of weed species. It will enable environmental managers to use drones for large-scale weed assessments, detecting them earlier and targeting on-ground actions like removing and treating them more easily.

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