What is narcissus bulb fly?
Bulb flies are hoverflies, the larvae feed on Narcissus (daffodils) and other bulbs in the Amaryllidaceae including Crinum, Eucharis, Galanthus (snowdrop), Haemanthus, Hippeastrum, Ismene, Leucojum, Nerine, Sprekelia and Vallota. Occasionally the underground storage organs of other families, such as Lachenalia, Iris and Scilla, can also be affected.
Large narcissus bulb fly (Merodon equestris) can be the more serious problem, as this has larvae that can attack and destroy healthy bulbs. The large bulb fly is not native to the UK but since it was first reported in the late 1800s it has become widespread.
Maggots of small bulb flies (Eumerus strugatus and E. funeralis) are usually a secondary, they feed in bulbs that have already been damaged by another animal, disease or physical damage.