I've been using a product containing Imidacloprid to control the beasts. A granular allpied once a year during Merodon flight/breeding season will usually keep the critters from infesting bulbs, especially the ones in pots. In ground control can be trickier. I'm less apt to apply Imidacloprid to the garden, as it is systemic and will kill other beneficial insects. Its use will also cause mites to become "extra-fecund". The population can explode and predators may have been eliminated. I always use pesticides will great caution, regardless of product. Sometimes, it's just necessary. Michael Interlaken, NY Z6 -----Original Message----- From: Christian Lachaud <email@example.com> To: pbs <firstname.lastname@example.org> Sent: Wed, Nov 14, 2012 12:41 pm Subject: [pbs] Merodon equestris (Narcissus bulb fly, greater bulb fly, large bulb fly, large Narcissus fly) Dear All, Merodon equestris larvae have infested bulbs in my garden (Narcissus) and greenhouse (Hippeastrum, Hymenocalis), which I discovered recently. There is usually 1 larva on each bulb, which is enough to destroy any blooming hope for 2 to 3 years, if not worse. These big fat worms locate usually at the bottom of the bulb, and may penetrate to the core and destroy the bud. Additionnally, the wet wounds they create usually cause the bulb to rot. May I ask about your experiences with this problem ? How did you get rid of the adults and larvae, what are the prophylactic measures, etc. ? Best regards.