I don't know how the life cycle of the bulb fly here in the Pacific Northwest compares with other regions, but here, the adults emerge simultaneously at a certain time in late spring and are immediately apparent not only visibly but also audibly. When they are flying, they produce a high-pitched whine similar to a mosquito but louder. At this time I make sure my bulb house, which has metal screen sides and a solid roof, is closed up. Bulb flies attack Galanthus (snowdrops) and Sternbergia as well as Narcissus in the open garden but I haven't lost significant numbers of those. I have read that the bulb flies are more likely to land on plants in sun than in shade, but my garden is mostly sunny. I did plant a large number of commercial daffodil hybrids at the road frontage, thinking the flies might be attracted to those cheap bulbs and leave my special ones alone. When I lived in the country, I grew Sternbergia in a raised bed and just threw a little sand over the plants when the foliage began to yellow. I have also read that the flies are attracted by the color of the withering foliage, which makes sense as their larvae have to make their way into the center of the bulb via the hollow left by a withering stem. Sternbergias go over well before most Narcissus do. When amaryllids are being grown in containers rather than in the ground, just covering the pots with a sheet of row cover (Reemay, etc.) would prevent bulb fly infestation and would not harm the plants. On 8/31/2021 4:52 AM, Arnold Trachtenberg via pbs wrote: > Luca > I’ve been using a number of new organic insecticides which represent a new class of compounds. > First group is based on bacteria that attack various parts of the pests metabolism > Spinosad has been around for a long time. > Grandevo and Vernerate are two others. You can search the names and find info on the web and on you tube > The most recent one is Spear-T. It is a peptide derived from the Australian Funnel Web spider. > I’ve had very bad attacks of the Narcissus bulb fly and think there are some of my images on the PBS Wiki. > Arnold > > > Sent from the all new AOL app for iOS > > > On Tuesday, August 31, 2021, 3:10 AM, Luca Bove via pbs<pbs@lists.pacificbulbsociety.net> wrote: > > Thanks Lee Poulsen > > Do you have an alternative to imidacloprid? > > imidacloprid and other neonicotinoids are banned in the EU. > https://ec.europa.eu/food/plants/… > > > > Il giorno lun 30 ago 2021 alle ore 23:20 Lee Poulsen via pbs < > pbs@lists.pacificbulbsociety.net> ha scritto: > >> 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> >> > _______________________________________________ > 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> _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> PBS Forum https://…