Bob Spotts, California

Large fly destruction

November 18, 2010
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Categories: Basal Rot, Bulb Information, Diseases and Pests, Growing Daffodils, Planting

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Many bulbs can be salvaged by removing the worm and replanting. (I add a dose of Clearys 3336 slurry.) You’ll often get a number of bulblets formed from the basal plate. David Karnstedt had the idea that the detritus (worm poop) contains agents that protect against basal rot. ‘Kokopelli’ survived large fly in its first/only bulb. It actually hastened the bulb multiplication.

Bob

4 responses to “Large fly destruction”

  1. Melissa Reading says:

    I just kill the worm by slicing the suspect bulb in half, picking out the worm, and slicing it in half. I doubt many of them go on to bother another bulb. I don’t want to run the risk of the pesky buggers flying “home” from the dump.

  2. Rod Armstrong says:

    God made Kokopelli indestructible! That large fly could have never destroyed your one and only bulb! – Rod

  3. Melissa Reading says:

    Yes, sometimes I hook the fly larva out with a wire, clean the bulb, and so on. But I was speaking to the case where some folks discard the bulb with the fly intact. To my taste, leaving the fly intact, even if in a well closed paper bag, is a poor idea.
    Interesting historical bit about Kokopelli!

  4. Jason Delaney, Missouri Jason Delaney says:

    KILL THE LARVAE! It can overwinter in bulbs sitting atop the compost heap!
    Not that I seek out such things, but to receive a bulb of new introduction through the mail, jam-packed with a large, fat larvae ready for the squashing, has benefitted my commercial program immensely by providing me copious offsets of that variety within just a couple years. Next year PHS will offer bulbs of some really nice selections—larvae-free, I assure you—as a result of this very natural form of micro propagation! 😉
    The fly and the bulb live symbiotically: the fly needs the bulb for its propagation, and the bulb benefits from the fly’s larvae for its propagation. Attacked bulbs will appear as clumps of grass-like foliage in the first and second seasons after the attack, versus standard-sized foliage and flower production. After a year or two of this grass-like state, the clump may be lifted, split, and lined out, which in some cases may increase the quantity from the original one bulb to twenty or more bulbs. Wow! Not every fly is truly bad!
    On softness, many bulbs manifest this state because there is a separation between their scales within the bulb, causing a spongy or soft feel to an otherwise healthy subject. I notice this from year to year on bulbs dug when the ground is saturated with moisture, and when the foliage on those particular cultivars isn’t fully mature (more in the long-necked bulb types than others, in divs 3, 4, and 9). If so inclined, cut the bulbs open, and you’ll notice they’re fine: there can be 1/8th inch gaps between the scales, indicating the bulbs weren’t entirely “hardened off” prior to digging. The scales should be clean and milky white all the way through, even if spaced out a bit. (Available soil nutrients at that time of the year may also play a role in this—I suspect it does somehow—but I’ve never tested it to find out).
    Conversely, bulbs firm and solid upon digging, if left out of the ground too long and stored cool and dark, may begin producing growth in the center of the bulb, pushing foliage out of the top and expressing root nodes at the crown. When this happens, the bulb scales are robbed of their moisture content to feed the emergent growth, which causes desiccation of the scales, which also creates gaps between the scales, resulting in that spongy or soft feeling.
    With either camp, these soft bulbs, when planted in the fall, still perform as well as those considerably harder and firmer to the touch.
    Rotten bulbs, due to basal rot, are very different from desiccation (sponginess) and bulb fly for very different reasons: The basal plate may appear chocolaty brown, and to the touch it is so soft, even crumbly, that a slight nudge might pop the whole thing off the bulb. To that end, if you cut the bulb open, the scales are tinged brownish, emanating from the bottom of the bulb, rising upward. Also, the rot has a distinct odor to my big nose, more musty and earthy than the mildly acrid and almost chemical-like odor from the frass of the larvae (has anyone else noticed that bulb fly larvae poo has a chemical versus musty or otherwise rotten odor? How’s that for a question to start your day?!).
    Jason
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