Leeks

The leeks are poor this year.  They are spindly undeveloped things with a diameter of only about 1cm. I decided to dig a few for lunch despite their disappointing size.   All of them seemed to be infested with small pupae.  These turn out to be the pupae of the Allium Leaf Miner.

This little blighter started as an egg laid by a tiny fly, developed into a larva, chomped its way through the leek and then turned into this pupa.  They are a new pest spreading from Wolverhampton and now prevalent throughout the West Midlands.  Apart from devastating leek crops they can have a similar effect on onions.  The best defence may be to put leeks into the ground later during the season and thereby missing the most active period for the flies.

This link Which? Gardening - Allium Miner Factsheet gives lots of detailed information on this bug.