Narcissus fly control

Narcissus fly can be eliminated virtually completely–I am tempted to say 100%–by using imidacloprid. It is sold in granular form as a grub killer for lawns. This chemical persists in the soil for about two months, according to the label, providing “season-long” control. Other products contain Dylox (sorry I don’t have the proper chemical name at hand), which has been approved for narcissus fly control. However, Dylox does not persist, and is advertised to be effective in “24 hours” or “overnight.” My guess is that it is more effective as a spray, in which form it has been approved for use on narcissus fly. I have used imidacloprid granules for several years now, and I have had zero flies. I apply a tablespoon or so around the base of each plant–more if it’s a clump–in spring before bloom. This interrupts the life cycle of the fly by killing the grubs, and there should be none the following year. I believe there are other granular “grub killer” products with a different “season-long” control chemical, but I have not used them. They might work just as well. Imidacloprid also comes in liquid form, and I see no reason why it would not work that way, too. For those who eschew the use of chemicals, I still think neem might be worth a try. Although I doubt its killing power, it may be obnoxious enough, when applied as a spray, to encourage mature flies to deposit their eggs on somebody else’s daffodils.

2 comments for “Narcissus fly control

  1. Just a note on imidacloprid. I live in the NC mountains where the hemlock wooly adlegid is killing hemlocks off at an alarming rate and the chemical of choice is imidacloprid, so us Master Gardeners here get lots of questions about it. If you live near water it isn’t recommended as a soil drench (arborists treat hemlocks near streams, etc. with trunk injections, but that won’t work for daffodils). It is also a suspect in bee declines; I don’t make any judgment about this, but here is one overview of the issue: http://en.wikipedia.org/wiki/Imidacloprid_affects_on_bees From the perspective of the hemlocks, an unwanted side effect is that it increases susceptibility to mite infestations.

    Debbie in Western NC

  2. Bob, You introduced me to imidacloprid. It comes in a concentrate form manufactured by BAYER. If you use the spray form, you have to spray the base of each daffodil until the mixture accumulates and drains downward. A thin spray does not do the trick. I spray when the daffodils first start blooming and again at the end of the bloom season before the foliage starts lying down to die. I’ve only been using it for two years, mostly out of my respect to the Bald Face Hornets that help me hybridize as it doesn’t kill them. Dursban that is banned kills just about everything insect or grub if you get it on them. So far very effective.

    Clay

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