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Kill or incapacitate a pupa with sound?

  1. Oct 9, 2018 #1
    Elsewhere there are discussions about the feasibility of killing bugs with ultrasound. All of those discussions consider a situation, presumably, where the bugs are in the air. That seems a tricky problem, but perhaps not the one I wish to discuss.

    The Problem: So in California we have this infestation of exotic beetles which are killing oak trees in large numbers. Their cycle is such that they feed on oak leaves, fly around, and breed in the late spring and summer. Most of the winter and spring is spent either eating oak wood underneath the bark or pupating etc. Poison works to varying degrees, but it is pure maintenance and cannot be used to completely eradicate beetles from a given area. It can also be expensive.

    I am wondering if these beetles can be killed with sound when they are pupa sandwiched between tree bark and tree trunk. I thought maybe microwaves, but that doesn't seem feasible without also maybe killing the tree. But sound seems plausible.

    I wonder if you need to reach the resonant frequency (yes you can span a range of frequencies maybe quickly to reach all the resonant frequencies in the body, whether that has the desired effect I don't know), or if you can make up for lack of resonant frequency with amplitude? Especially if perhaps you can make the tree into a sounding board whereby you might transform, say, a 150 db sound into something much, much louder? And you need not kill the beetles, just incapacitate them so that they can't breed.
  2. jcsd
  3. Oct 10, 2018 #2

    jim mcnamara

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    I am pretty sure massive bursts of sound will not work well at all.
    After a search: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7422.html (no sound mentioned) Consider reading the article.

    First off, the larval stage does most of the damage, as you probably know. Healthy trees survive oakworm attacks. I would posit that trees in drought-stricken areas would be more affected.

    The link I gave you suggests control strategies. I see no mention of sound. As guess, if you could damage the pest species with sound you would concurrently be "damaging" most of the other living things in the area: specifically the vascular cambium of the tree. Kill the cambium cells, kill the tree as well. There would also be collateral damage to beneficial insects and other organisms.

  4. Oct 10, 2018 #3
    Thanks for your reply. This particular worm is called the gold spotted oak borer, and mortality in all infested red oak varieties is 95% (yes that’s right all the trees are dying) . Drought seems to affect how long it takes the tree to die, but doesn’t prevent it from doing so. Pretty sad. So at this point I’d consider almost any tactic. I also thought if some mechanism to detect the location of worms under the bark was feasible, you could simply smash them.
  5. Oct 10, 2018 #4
    Google up 'tree injection'. You might be able to find adequate pesticide to be applied this way for these bugs, but please keep in mind that some pesticides might require special permission and: sometimes it is just how nature works and instead of forcefully trying to preserve the existing balance it is better to seek for a new one.
    Last edited: Oct 10, 2018
  6. Oct 10, 2018 #5
    The gsb has no natural enemies in the area except woodpeckers, and they don’t do enough. Gsb is native to New Mexico
    Yes I’m familiar with all the pesticide methods for treating gsob including tree injections, spraying and soil treatments.

    There is no balance, all the trees will die if left untreated.
  7. Oct 10, 2018 #6


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    Few infestations of invasive species have ever, to my knowledge, been eradicated. It is not an easy thing to do.
    The larger the area and invasive population, the greater the problem and expense.

    The co-introduction of natural predators of the initial invader has, on occasion, provided some reduction of in the invasive population, but there are numerous other instances when this has not worked out well and has created more problems.
    Because of this, the introduction of non-native predators is usually carefully scrutinized (with lots of studies) before any intentional release.
    This thread is about an example of such a case.
  8. Oct 10, 2018 #7


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    Focused ultrasound is used as medical treatment already, so your flailing around with ultrasonics is not without warrant.
    Just keep plugging away on the feasibility of a possible technology.
    Wiki has brief write up and you can go from there to present something adaptable for trees.

    Problem is pinpointing the location of the bugs under the bark, with the inconsistent depth of bark and bug location, and time consuming for each tree, and maybe expensive as a result. One can conceive of an electro-mechanical device, perhaps a ring, that walks up the tree and locates and eradicates. Branches would have to be inspected I would assume also.

    How then does one 'save' the tree though from another re-infestation is another matter.
  9. Oct 11, 2018 #8

    Yes locating them would be a problem. Birds do it, but I’m not sure we know how. Maybe it could be done with some kind of X-ray, radar or thermal imaging. All of which seem time consuming and require expensive hardware.
  10. Oct 11, 2018 #9
    Maybe pheromone traps, then?
    But, honestly I think it is hopeless. Once this kind of thing started it just won't stop till there is enough food around.
    As I've just thought about this yesterday, we here (middle-Europe) has something like four or five similar cases and I'm expecting more.
  11. Oct 11, 2018 #10


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    I have always heard that woodpeckers use visual indicators of infestations and well as the sounds of grubs chewing wood.
    from Wikipedia:
  12. Oct 11, 2018 #11


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    Scientists are researching ways of using CRISPR to develop genetic elements called gene drives that can spread throughout populations of species in the wild and eradicate them: https://www.wired.com/story/crispr-eradicate-invasive-species/

    A recent study provided a proof of this concept, designing a gene drive that could eradiate a population of mosquitoes in a laboratory setting:

    Less high tech versions of this approach have worked in eradicating screwworms (which eat the flesh of livestock) from the US and other countries: https://www.aphis.usda.gov/aphis/ou..._release_programs/screwworm/screwworm_history
  13. Oct 16, 2018 #12
    This is going to veer a bit off the topic of physics and into biology.

    The balance is achieved when the amount of food available limits the population of the borers. Whether that leaves a viable number of trees to reproduce is questionable. What is missing in this discussion is whether some of those oak trees are resistant or even immune to those borers. One of the major problems with the American Chestnut blight was efforts to prevent its spread consisted of clear cutting every tree; which had the unfortunate effect of destroying those trees that had some resistance or immunity to the blight. There are currently two breeding efforts that I know of in the U.S. to produce blight resistant American Chestnut trees. One is cross-breeding American Chestnuts with Chinese Chestnuts (which are highly resistant) to produce a resistant hybrid, and then breeding back in American Chestnuts to reduce the undesirable Chinese characteristics; it's still a hybrid and not a pure American Chestnut. The other consists of locating surviving American Chestnuts in the blight region, which are assumed to be more or less resistant, and breeding those together to produce a 100% American Chestnut resistant to the blight.

    Whether your oak trees have any naturally resistant members or not is the question. If there isn't any, you may be looking at an extinction event.
  14. Oct 16, 2018 #13
    In the areas hit heaviest, the first point of infestation, which occurred about 10 years ago, mortality is 95%. So maybe 5% are resistant trees, though perhaps they are simply getting more water than most and are just taking longer to die. In the gold spotted oak borer's natural habitat of New Mexico, red oaks have like a 15% mortality rate (I'm not sure on the exact number), and I've been informed we don't know why: genetic resistance, natural predators, climate, or something else?

    Supposedly the trees respond well to heavy watering, heavy fertilization, and heavy pesticide and/or anti-fungals. Pesticide isn't great because it also affects many other animals such as bees. I don't know how anti-fungals affect the ecosystem.

    At this point we're just trying to save "legacy" trees: ones that are strategically placed and/or are interesting looking, because expense and time preclude any other approach.

    All that said, maybe there is hope. The borers do not attack young trees, it only attacks trees with trunks that are 17 inches or greater in diameter.
  15. Oct 16, 2018 #14
    I assume that precision genetic alterations and/or protein manipulations will be the way to eradicate most diseases in the future, though it is unlikely to help in the critical next 10 - 50 years for these trees. Very promising.

    The radiation method seems tough but maybe doable..... these beetles are known to mate in May primarily, and at that in the very tops of the oaks trees. Precision drops of beetles could be done with drones, however, collection of the initial beetles seems hard to do because again their adult lives are spent 50 feet off the ground. Further, who knows if radiation would sterilize without killing.
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