Narcissus Bulb Fly
Merodon equestris
Narcissus Bulb Fly
Narcissus bulb fly (Merodon equestris) by Richard Avery (CC BY-SA 3.0)
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Narcissus bulb fly (Merodon equestris) by Richard Avery (CC BY-SA 3.0)
1 of 4
Narcissus Bulb Fly, or, Merodon equestris, is a bee-mimicking hoverfly whose larvae bore into the bulbs of plants in the genus Narcissus. They're also known to infest the bulbs of Crocus and Snowdrop.
Merodon equestris is frequently sighted in gardens as well as in suburban habitats with abundant flowers.
The main symptoms include bulb death or failure to produce flowers. If an infestation is suspected, bulbs should be dug up and disposed of as soon as possible.
Traits

Hoverflies are great pollinators.

Larvae will eat the bulbs of Daffodils and Snowdrops.
Appearance
Adults: They look convincingly bee-like! These flies have evolved over the years to (almost) perfectly replicate a bumblebee. They are large, reaching 1.5cm. They are fluffy, like bees- and this makes them great for pollinating flowers. They possess some banding, which starts with orange fur, leading to a black thorax, with their rears brownish-yellow.
Larvae: One larva will infect a bulb. They look like plump, creamy-white grubs. They are nearly 2cm long.
Symptoms
Infested bulbs are often killed.
Infested bulbs do not tend to produce flowers.
Leaves which do grow can be stunted and yellow.
Damage is not normally recognised until it's too late.
Activity
Diurnal
Personality
Order
Diptera
Family
Syrphidae
Metamorphosis
Complete
Distribution
Europe, America and some parts of Asia
Biological treatment
These flies dislike shade, so they can be avoided by planting daffodils and other bulbous plants near cover.
Firm down the spoil once bulbs have been planted. This will make it harder for females to deposit eggs.
Be sure to buy good quality bulbs and inspect them carefully before planting in the garden.
Chemical treatment
There are currently no appropriate forms of chemical control available for home gardeners.