I didn’t see that anyone had responded to this. When I first started growing bulbs in pots (here in inland Southern California) I had never seen a narcissus bulb fly nor had any bulbs eaten by the grubs. Then one year I started seeing these giant bumblebee-looking insects flying around my yard. Starting the next spring, I started not seeing some of my Narcissus varieties never leaf out. When I dumped out the pots, I found husks of bulbs in them. Then I started finding grubs inside bulbs when leaves suddenly wilted during the growing season. I tried various non-insecticide methods, but none of them ever worked. Finally I heard about imidacloprid and found an insecticide that contained it. My grub problem instantly vanished and has never returned. There are issues with using imidacloprid and damaging honeybees. So I only use it on my amaryllid bulbs and a few others that are prone to this kind of insect damage. I sprinkle a granule form of them on my pots, never a spray that uses it. And I wait till after the flowers are gone. (Because I worry that some of the insecticide might get into the nectar or pollen of the flower. It is systemic, so it flows through the plant and into the leaves and roots of the plant.) I also try to switch to some other systemic insecticide granules from a different class of insecticide every other year so as to not contribute to building up resistance by the narcissus flies. (I do the same thing with flea drops on our cats. One month an imidacloprid-based flea drop, the next month a fipronil-based flea drop.) --Lee Poulsen Pasadena, California, USA - USDA Zone 10a Latitude 34°N, Altitude 1150 ft/350 m > On Aug 29, 2021, at 5:42 PM, Danny Wylie via pbs <pbs@lists.pacificbulbsociety.net> wrote: > > Hey all, > > I've been in for a nasty surprise this growing season in northeastern Ohio > as my bulbs have been hit hard by the fly. So far every 2 year old > Hippeastrum bulb has them. After I discovered them attacking most of my > large bulbs I wanted to try keeping the bulbs in my hot greenhouse thinking > it would maybe deter them, but I was not successful. They will gladly go > after any amaryllid about the size of a quarter. I would do the hot water > method but my bulbs get attacked so young that I fear I would never see > them flower again. I'm researching insecticides for control and the wiki > suggests dylox. I've also read that a daffodil grower found Imidacloprid > highly effective. Has anyone used these for containers and found them > helpful? > > Big thanks! > > Danny W > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > http://lists.pacificbulbsociety.net/cgi-bin/… > Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>