[Anton]

Hullo Fellow Gardeners,

I am here with my eternal leeks questions again.
I have two rows of leeks covered with mesh to keep off the dreaded moth.
I was wondering when the moth actually stops laying eggs so I can remove the mesh. Does anybody know?

Anton

[JayG]

In the UK at least there is the allium leaf miner to worry about as well as the leek moth.

Without looking them up I'm pretty sure at least one of the pests has at least two breeding cycles per year, the second being in early autumn.

I'm guessing that the situation in Belgium is not likely to be much different, so you need to keep them covered for at least a couple more months.

[mumofstig]

RHS

Leek moth has two generations during the summer with larvae damaging the plants;
•From the first generation in May-June
•And the second generation in August-October
•The second generation is the more numerous and damaging

Allium leaf miner has two generations a year:
•First generation female flies lay eggs on the stems or base of leaves during March to April
•The second generation repeats the process in October to November, this generation is usually the most damaging

[Anton]

Thanks a lot for your answers.
Another problem is the two rows of leeks seriously need weeding. Once again, I might have answered this question before but do I dare take off the entire netting for 30 minutes or so in the evening to do this?

Anton

[Blewit]

do I dare take off the entire netting for 30 minutes or so in the evening to do this?

I would and if the leek moth does manage to sneak in cut off affected leaves below the caterpillars, the leek will regrow. I mulch around leeks with compost which stops most weed seeds germinating.

[Salmo]

Thanks a lot for your answers.
Another problem is the two rows of leeks seriously need weeding. Once again, I might have answered this question before but do I dare take off the entire netting for 30 minutes or so in the evening to do this?

Anton

Leek moths are "MOTHS" and therefore come out at night. You can take the covers off in the daytime, certainly not in the late evening.

The first egg laying period is in May-June. The eggs are laid singally at the base of the leeks, hatch in a week, feed for 2 weeks, pupate and then hatch in two weeks into moths.  That is a cycle of 5 or 6 weeks, depending on temperature.

These adult moths mate and lay around 80 eggs over a period of about 3 to 4 weeks. The emerging caterpillars are the ones that do the damage.

Working on with the 5 week life cycle, eggs laid at the end of June will emerge as moths in the first week of August and lay their eggs during the next 3 or 4 weeks (right now). Therefore egg laying should be completed by early September. i.e. you can remove the mesh. Nature does not always keep to the rules so to be safe shall we say remove the mesh in the second half of September.

The moths hatching from this second generation hibernate in debris and rough areas ready to emerge in the Spring.

[Anton]

Thanks very much for all of this useful information.

Anton