Onion fly



 

The fly, which is similar in appearance to a house fly, is active in May. Eggs are laid on onion leaves or on the soil nearby.

 

The maggots which hatch tunnel into the centre of the bulb, causes the leaves to turn yellow and wither and the bulbs to rot. A second brood of flies emerges in July or August, and this time overwinter as pupae.

 

  • Destroy affected plants.