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bernerfolk

Nematodes for plum curculio

bernerfolk
9 years ago

I've been reading research on the effectiveness of the nematode Steinernema riobrave, particularly strain 355, in controlling plum curculio in orchards. Has anyone tried it or know of a source for this specific nematode? I'm only dealing with a new planting of (5) plum trees so economics aren't really a factor... I'd just like to do what I can to manage pests organically. Here in the Berkshire ( Z5 ) it's too late for a kaolin spray but I think the timing is good to hit the late stage instars and new adults.

Comments (14)

  • Scott F Smith
    9 years ago

    I haven't heard of this but in reading up it sounds like there are several strains that may work which may be commercially available. I might try one of them as I have a lot of curcs this year -- I got all the early ones but stopped spraying too early.

    Scott

    Edit: I just purchased Dr. Pye's Scanmask which is S. feltiae. It may not be the SN strain of the article but I'm not sure how much difference the strain makes. We'll see if it works. Thanks for pointing out this approach.

    Here is a link that might be useful: nematode article

    This post was edited by scottfsmith on Sat, Jul 5, 14 at 11:08

  • alan haigh
    9 years ago

    The study I'd like to see would be about the efficacy of eliminating or reducing them from your orchard floor- how much relief that would bring as they are extremely mobile and capable of coming from a good distance in a short time?

    Milky spore may kill J. beetle larvae but I haven't had much success with it on a couple of sites where they are a consistent issue, although after spreading it on my own property I've been free from major assault for well over 20 years. They were bad every other year before that. More recently I've wasted my client's money with the tactic.

  • Scott F Smith
    9 years ago

    Hman, the curculio are vulnerable when they have fallen from the plum trees - they can't fly before they have turned into adults. The Japanese beetle larvae can be in your whole yard or the neighbors', but curc larvae can only be under plums peaches etc.

    Scott

  • alan haigh
    9 years ago

    But there isn't a way to stop them from coming in from other locations- they are pretty much everywhere and highly mobile. When I kill nearly all he larva by poisoning the fruit in an orchard is doesn't stop them from coming from elsewhere the following season.

  • Scott F Smith
    9 years ago

    The curc needs plums or similar to eat, and at least around here I don't think there is a lot they can eat that is not in my yard. Or maybe they can feed on other things? I thought they were pretty specific to fruits. Or maybe there are enough wild/ornamental fruits about. My huge ornamental plum produces a couple fruits every year and they get PC.

    Scott

  • olpea
    9 years ago

    "But there isn't a way to stop them from coming in from other locations"

    That seems to be what the literature indicates. From what I've read, the outside rows of trees are the ones first hit in commercial orchards. Fruit specialists warn to pay special attention to the outside rows for PC, indicating PC migrates in the orchard.

    It may depend on how much forested area is in proximity of the orchard. Orchard areas with lots of timber nearby probably won't find predator nematodes very beneficial against PC in my opinion.

    For myself, I see PC every year of course, but can't conclusively say it migrates in. I think it does because I can't imagine PC surviving insecticide sprays.

  • Scott F Smith
    9 years ago

    My understanding is the PC likes to overwinter in woods/tall grass out of the orchard. So, they wake up in the woods in the spring, fly to your orchard, do their business, and molt to adults under your trees. If the cycle is broken at this last step they won't be in the woods to fly to your orchard the next spring.

    One sign of how many of your PC come from your own orchard is to remember when you first put it in. For the first year or two I had little PC damage because I had not built up the local population yet. It was the third year when things got bad.

    Scott

  • olpea
    9 years ago

    "My understanding is the PC likes to overwinter in woods/tall grass out of the orchard. So, they wake up in the woods in the spring, fly to your orchard, do their business, and molt to adults under your trees. If the cycle is broken at this last step they won't be in the woods to fly to your orchard the next spring."

    That makes sense Scott. I think the challenge would be all the unmanaged fruit trees and wild hosts.

    Of the little crop of peaches at the farm, all of them (unsprayed) dropped from worm damage, despite no crop before. I don't know if it was OFM or PC, but it was early enough it could have been PC.

  • alan haigh
    9 years ago

    Amelanchier, shadblow or juneberry is a major PC fruit but there are others, including native crab apples, blueberries (according to one university source)and native plums. Not to mention the many unsprayed fruit trees in abandoned orchards and homeowners yards. They are long distance fliers and in the literature for commercial growers they speak of them flying very long distances in a short time and arriving in great numbers over night.

    The point is, if they could be controlled or even greatly reduced by applying nematodes I would expect there to be some verifying research. This single pest is responsible for so much damage and the application of so much pesticide that there is plenty of money and interest for this type of research.

    In the orchards I manage, most of the ones in the trees are killed by poison before they reproduce- but there they are, every spring.

  • drew51 SE MI Z5b/6a
    9 years ago

    "I would expect there to be some verifying research"
    Good research takes decades, this is a relatively new product.

    "most of the ones in the trees are killed by poison before they reproduce- but there they are, every spring. "

    Maybe you should try nematodes?

    "Amelanchier, shadblow or juneberry is a major PC fruit but there are others, including native crab apples, blueberries (according to one university source)and native plums. "

    Never seen any of those here, and I forage for fruit, do know the area.

    "Milky spore may kill J. beetle larvae but I haven't had much success with it on a couple of sites "

    Most experts recommend nematodes in short season locations. MI, MN, RI etc. If you have a winter, forget milky spore.

  • Scott F Smith
    9 years ago

    My nematodes are going down tomorrow so ask me next spring how thick the PC are :-)

    I don't think masses are flying in. I can often count the number of PCs in my plums since their activities are localized in a few trees. This spring my front plums had only one PC active in one spot; I got very few infections. 100' away in the back orchard I had more and a particularly bad late infestation that was the work of only a couple of them, again based on spottiness of the infestation. The average curc lays 15-20 eggs per day for a solid month. Thats a lot of eggs! I find I can make a significant dent by crushing them at night: eliminate 5 females and progress was made!

    Scott

  • eboone_gw
    9 years ago

    Does PC infest native black cherry fruit? There is a lot of that in my neighboring woods.

  • alan haigh
    9 years ago

    Drew, I have clients in a Z7 where MS should not be winter killed- at least in previous 8 winters before the last, when lows there didn't get under 10F.

    Mine was actually a Z5 when I first spread MS, and as I said, I've never had a bad infestation since, which certainly could be coincidental. Later it became often suggested that N. of Z7 MS could be winter killed- but just try to find the research!

    The poster is in the Berkshires, where I assume amelanchier are very common on north slopes, as they are here- why do you respond as if I was speaking to you?

    The comment about "maybe I should try nematodes" comes off as- well you know. I manage far too many orchards to rely on a theory- my customers expect their fruit every year- and I know my own woods are full of PC and other pests that require the same spray.

    The point of the comment was that if I'm killing my curcs but new ones show up the following year, than they must not be coming from the soil of the orchards I manage- which is exactly what the experts lead me to expect, based everything I've read about PC over the years.

    Maybe for Scott they will be affective if he's surrounded by developed land, but if they've been coming out of his soil only, where did they come from to begin with? Still, he's often been pleased with results of his own special methods so I wouldn't suggest he follow my point of view- I just throw my opinions out there for discussion.

    Every orchard I plant has PC as soon as trees have fruit and it is not a problem that multiplies year after year on unsprayed trees- that might indicate something.

  • drew51 SE MI Z5b/6a
    9 years ago

    "why do you respond as if I was speaking to you? "

    I was speaking for all of SE MI but I guess we don't count? Those fruits are not here, and the nematodes may work better here, I guess you didn't want to hear that?

    "The comment about "maybe I should try nematodes""

    That was a joke, I couldn't help it. The setup was just too good! I guess your negative attitude to anything new is irritating. Others won't say it to you, i will.
    Most people have a filter, and are polite, I'll never be like that, can't help but comment. We really do need more time to see if these work, they may not, but I figure it's worth a try, it can't hurt and may help.
    I know nematodes do not last, so one would have to apply probably for a few years.
    I must say fighting these critters is frustrating as we seem to never be able to get rid of them, just manage them, and new species keep coming in all the time.
    In upper MI we do have all those plants you mentioned,. Luckily not here, except for the ones I planted!

    " I just throw my opinions out there for discussion.
    "
    Same here, really all i was doing. I too live in an isolated spot. SWD fruit fly has yet to find my berries even though in the state. I really wish I didn't have to move. At least the move is not that far away, but more in farming land. If possible, if a miracle happens and I come into loads of cash, I'll stay here.

    Anyway bernerfolk, I would try it, that is my advice. I would not wait decades for accurate studies. You have some research anyway, go for it!
    That was what I was saying, As I see I have to make that clear.