Narcissus bulb fly (NBF) is a fly; it's in the order Diptera. Its "grub" is a maggot. Bayer 24 hr Grub Killer Plus is effective against "grubs" -- that is,against the youngsters of certain beetles. They belong to the order Coleoptera. So it won't work against NBF. (Sorry.) Jean, in Portland, OR -----Original Message----- From: My Tong <electric.rice@gmail.com> To: pbs <pbs@lists.ibiblio.org> Sent: Tue, Oct 22, 2013 2:25 pm Subject: Re: [pbs] Large narcissus fly Hi all, I'm a relatively new grower of Hippeastrum this year. Well, I just found a fat NBF larvae together many smaller larvae that don't look like any of the lesser bulb fly in quite a few of my hippeastrum pots. ... I'm curious if one can mix the Bayer 24 hr Grub Killer Plus (Dylox) with water and use this mixture to spray in the hole to eradicate all the larvae? ...