What is narcissus bulb fly?
Bulb flies are hoverflies, the larvae feed on Narcissus (daffodils) and some 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 be attacked by the larvae of two different types of fly.
The more serious problem can be large narcissus bulb fly (Merodon equestris), 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 has become widespread.
Maggots of small bulb flies (Eumerus strugatus and E. funeralis) are usually a secondary problem that infest bulbs that have already been damaged by another pest, disease or physical damage.