Software
Houzz Logo Print
hzdeleted_8959062

Biological pest control - thoughts?

13 years ago

This year, my cytisus was infested with broom gall mites - had to practically chop it in half to remove all the infected branches. Anyway, looking up info on this, I was amazed to read that the mite was being released in Australia and Oregon, to combat invasive gorse. Various bacterial and fungal organisms are being pressed into service (the Japanese knotweed beetle has been released in the UK). These non-natives often have no predators....supposedly dying off when the 'host' weed is eradicated. As if!
Even odder (to me) is the enthusiasm for these controls by many people for whom chemical use is the first step before you end up dicing with Dr.Death. Organic gardening catalogues are stuffed with them (bio-controls). Anyone find these parasitic wasps, spores, bacteria bit worrying? Or (more likely) have I got hold of the wrong end of the stick?

Oh yeah, the ladybirds - the ferocious (and cannibalistic) asian Harlequin ladybirg was introduced in Europe to act as super-munchers of aphids....but unfortunately they ate the native ladybird species too.

We have form for meddling....and it often goes arse-up.

Comments (13)

  • 13 years ago

    I receive a monthly order of "fly predators" during the summer months that I release around my farm to reduce the stable fly population. The option would be spraying noxious chemicals into the air of my barn and another set of chemicals on my horses to keep the flies from driving us all crazy. I think this particular solution as been in place a couple decades and I've not heard of any negatives. It is quite effective.

    I think "often" goes arse-up is an over-statement. Sometimes? Yes, but generally these things have some pretty good research and "often" are quite effective in providing a less damaging solution to a problem.

  • 13 years ago

    camp, of course you are correct - history is full of examples of well intentioned release of non-native insects or other animals into an ecosystem which resulted in disaster.

    A few decades ago our park service released wild turkeys into some isolated areas in No California - the idea was that they would make good "hunting" for people who like to shoot birds. Well, of course we are now up to our eyeballs in wild turkeys in all of the suburbs around here - they walk down the middle of streets, they live in the parks, etc. Last when my DH was on a bike ride near our house, a tom chased him as he was peddling so slowly up a hill (it was Spring, and there were hen turkeys around - I guess he took my DH for competition!). The not funny part is that, several times flocks of turkeys (which are VERY heavy and large) got spooked, all took to the air together, and wiped out and were wiped out by the power lines, causing power outages.

    I am an advocate of letting the biological pest controls that are already in our environment (or would be, if we didn't kill them). The aphids have arrived on my roses in the last 2 weeks, right on schedule. However, in the past few days I have seen ladybugs, ladybug larvae, soldier bugs, and a little tiny bird all descending on the roses and feasting on the aphids.

    Jackie

  • 13 years ago

    Oh dear. I am in aphid-hell! I am hosing off new growth every other day (every day on Lav Lassie). I have noticed ladybugs and larvae and lots of birds flitting around my roses.
    But I have to confess, I've thought about ordering some ladybugs.
    I seem to have lots of birds around my yard. I just need to attract the insect eaters.
    Camps, I remember reading something about rabbits being used for a biological control on an island--they destroyed it.
    Weren't mongoose used to control snakes and then they overran the country?
    I dunno.
    Some of this stuff really bothers me. But fly predators? I'm all for it...
    Take mosquitoes (please) what purpose do they serve in the ecosystem? I'm sure they aren't the only sustenance for their predators....
    Susan

  • 13 years ago

    When I hear about another one of these hairbrained ideas, my hair stands on end. We have cane toads in the sugarcane fields that have decimated the native toads in south Florida. We have Cuban tree frogs that are decimating the native tree frogs all over central and south Florida. Lion fish eating all the native fish. Constrictors decimating all the wildlife in the Everglades including the ALLIGATORS. Multiflora planted everywhere, and it's the source of the mites carrying RRD. And thats only the stuff I can think of off the top of my head, and doesn't even mention all the invasive plants turned loose in Florida. It's all man made. Man's meddling is destroying this planet a piece at the time. Sorry for the rant.

  • 13 years ago

    Susan,
    I bet if you wait, and don't tidy up your yard too much, you'll have all the ladybugs you need. My garden is full of them. I don't use pesticides in my garden, and our property has lots of rough areas full of unmowed grass, little herbs, shrubs wild and domestic, and all the untidy growth that ladybugs overwinter in. I turn them up all the time when I work outside. We have some serious bug plagues, the worst being two kinds of beetles that love rose blooms, and cane girdler. But in the case of aphids Mother Nature does a pretty good job of dealing with them.
    Suzy, I share your skepticism. It seems reasonable to look for control species that are native to one's area and encourage their growth, rather than bring in risky exotic "solutions".
    Melissa

  • 13 years ago

    subk3 - living on a small island, I do not have your faith that these things are solidly researched - or at least they are....with an agenda already in mind (profit). Frankly, I find your optimism a tad chilling since we are practically overrun with a mix of American Crayfish, mink, chinese water deer, Muntjacdeer, newly introduced beavers, wild boars, already mentioned the cannibal ladybirds (I would be very concerned about what specific insects you were ordering, Susan, as I believe the Harlequins were also released in the US - although the cats already out of that bag).....and now we are heading into microlife invaders.
    Feeling angry and somewhat helpless - at least with chemicals we had a choice - they didn't spread around the countryside willy-nilly and you could decide for yourself what your cultural preferences were.

  • 13 years ago

    Nature bats last. Non-native species have always been introduced, tho admittedly human behavior introduces more and faster. Nature adjusts; she just may not adjust the way we want her to. We have a static vision of how things should be, but nature is dynamic. Both those who introduce non-natives and those who are against doing so think they know what is a good objective and what the long-term outcome will be, but neither knows for sure. In my garden, I have dozens of non-native plants. So far, most seem fairly innocuous. But lavender is not native to SW Virginia and probably for good reasons.

    The profit motive is not the only bad guy in this. Our concepts of what is a good garden or a pest free home or the best use of land are also to blame. We are unwilling to live with flies and crabgrass. We want orchids, a view and pets without fleas.

    We do not know diddly about the balance of nature.

  • 13 years ago

    Does any body else see the irony if not down right hypicritcal nature of a *gardener* and one who espouses old garden roses at that, bemoaning the introduction of non-native biological matter by others? Seriously?

    We wouldn't even have a tiny fraction of the Old Roses we have today if they had not been historically one of the most imported/introduced non-native flora. I'm sure in the 1800s all the little nasty critters in the soil and on the plants were in on the adventure as well and were passed all over the world. The reason: none other than vanity.

    And yet we can be critical of farmers and ranchers and others who introduce non-native biological matter in an attempt to try to improve their lives and the lives of others. And of course, we have show our spite that in doing so they were trying to make a buck to feed their families and put shoes on their kids.

    And no campanula, when those chemicals travel with the water flow and pour out of the tap in your kitchen you don't have much say in the matter.

    Sorry I miss read you original post. I though it said "-thoughts?" I missed where it said " only in if you agree I'm right share you thoughts."

  • 13 years ago

    Well hey, I am not espousing chemicals either, but I am profoundly uncomfortable with the continual movement of non-native bacteria and fungi into an ecosystem which has not been able to adapt at speed of global travel. And yes, we are paying the price for the untrammeled movements of organic materials across oceans. Regarding plant species, we have witnessed the dying of bluebell woods as the more vigorous Spanish bluebell out-competes and hybridises with our native bluebells. RRD from eriophyid mites have arrived from Asia (along with citris longhorn beetle and a host of other problematic life-forms) during my lifetime....and there is no cure on the immediate horizon. For some, who must have variety and novelty, I guess this is seemingly a price worth paying....and for sure, we cannot turn the clock back to a simpler time when we grew natives, wild flowers and local foodplants....and nor would I wish to do so. I do, however, wish for a wider research base, with a more rounded agenda and a bit more of an attempt to understand the dynamic interconnectedness of life. The theory that Japanese knotweed beetles will simply die when they have eaten all the host plant is rubbish - the beetles are being introduced because the current chemical treatment costs massive amounts of money (Japanese knotweed being, in turn, an introduced species with no natural predator). See how the cycle turns?- with no natural predators to act as a counterbalance, we really have no idea what effect this will have upon our finely nuanced eco-system. Moreover, others are not happy with having these things foisted upon them (such as our groundwater being poisoned) - I just hope that the greater awareness we now have regarding how we operate in a shared world will encompass a more rounded and holistic view where a short term profit is not developed at the long-term expense of balance.
    Hopefully, the brouhaha about chemicals will also spread so we question short-term fixes because we really do not fully understand the workings of the natural world....
    Writing this from the fens where a tradition of intensive agriculture and monocropping is turning the most fertile alluvial soils in the UK into a dustbowl reminiscent of Oklahoma in the 1930s. Yep, I am gloomy and somewhat despairing.

  • 13 years ago

    Grief, you are absolutely right - getting a bit intemperate (that's the kind term - a more truthful one would be hectoring).
    I start out quite 'thoughtful' myself....and get progressively rattier and rattier as my post progresses until I am swearing and muttering at the keyboard.
    Please forgive, there was no need to get on my high horse at you (wrong target).
    Cheers, Suzy

  • 13 years ago

    "For some, who must have variety and novelty, I guess this is seemingly a price worth paying...."
    Cheer up Suzy! Just think corn (maize) is indigenous to Central America and Wheat is indigenous to North Africa and, yet it was the introduction of them as food crops outside their native habitat that fed the population growth of the Western Hemisphere and today carries a heavy burden in the process of feeding the world's hungry.

    Please don't think I disagree with the ravages of invasive exotics. I'm just also aware of how their introduction into new environments have on occasion been very beneficial to humanity. For every case where it has turned out poorly there are 100s if not 1000s of cases where they did no harm or in which there were/are huge benefits. So, for me it's the whole baby/bath water scenario.

    The glass is half full! ;-)

  • 13 years ago

    Well, kudzu was surely not a wonderful idea. Supposed to control weeds. Hah! This stuff eats huge trees.

    kay

  • 13 years ago

    I can see both sides.

    I think the side that wants to cling to the status quo, who want to preserve everything for preservation's sake, forgets that nothing stays the same. We wouldn't be here if it weren't for mass extinctions in the past.

    On the other hand, those who want to tamper willy-nilly without thought for the consequences, thinking only of the dollar or personal convenience, risk pushing nature to the point that life itself just won't recover. I have no problem with the idea of we humans totally offing ourselves because we can assume nature will reassert itself and return to it's pristine state before we arrived to mess it all up. We're at the top. We're completely dispensable. But it would be sad if we screwed it up so badly that nothing could live ever again.

    Of course, given the ultimate fate of the sun (supernova) and earth (burnt to a crisp) perhaps it's all moot anyway. :-)