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leek moth attack


By ladbrokes - Posted on 30 June 2011

im gutted to find that my transplanted leeks have been attacked by leek moth. the thing is that ive covered the bed with enviromesh aswell and they still got in. any ideas. i was thinking off double netting. ive chopped the 15 or so leeks down to ground level

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Isn't there any other natural solution for these pests, besides chopping them off? My plants are also suffering from the moths and so far chopping didn't worked. Now I'm starting to consider calling advanced pest control in and save my plants once and for all.

 You don't want nasty apc! I find, so far, that growing storng plants in fertile soil enables most of them to survive and then re-grow in late autumn & winter, I never cut them off.

 Oh dear, I wonder if there were eggs in your transplants before setting them out. I have experienced a little damage in garlic so the adults must be flying throughout spring, probably in small numbers, but enough to cause damage like yours. One idea is to raise seedlings indoors for transplanting, then cover immediately.

I must go and check my own leeks!

after chopping the leeks back a second time due to moth attack they are now looking very healthy

Hello fellas...

We seem to be experiencing the same problem, and were wondering exactly what you might mean by 'chopping back'? Do you mean trimming off any effected leaves, or thinning effected plants?
Thanks,

JP.

i chopped back to ground level

 Ladbrokes, your soil is clearly in good heart to regrow leeks like this.

Another way: I do not chop as I have found (so far) that leeks recover from about mid October once moths hibernate, and leeks' regowth is stronger for being able to photosynthesise with their outer leaves still present. 

id like to think that all the horse manure and recycle compost that ive put onto the soil is working.

 The principal entomologist at the RHS, Andrew Halstead, sent this useful repsonse to a friend's worries about his disappearing leeks:

Leek moth seems to have had a particularly good year in 2011, judging by

the number of enquiries that have been received by the RHS Members' advice

service. Garlic and other onions  are also attacked but this year's

infestation is unlikely to be due to the fact that you grew garlic last

year.  This pest has become more widespread in southern England and south

Wales in recent years and adult moths could have flown on to your plants

from other gardens and allotments in the area.  No part of the moth's life

cycle takes place in the soil, so nothing needs to be done with the soil.

Leek moth has two generations during the summer, with the larvae being

active during late May to June and again between August and October. The

larvae feed initially as leaf miners in the foliage but as they grow

larger they bore into the stems of leeks and into the bulbs of onions.

Heavily infested plants often succumb to secondary rots but those that

survive can still produce a crop, despite extensive damage to the foliage

during late summer. When the larvae have finished feeding they emerge from

the plant and spin net-like silk cocoons, usually on the foliage. Pupae of

the late summer generation are present during September to October and the

adult moths emerge during the latter month. This pest overwinters as adult

moths that seek sheltered places during the autumn.

It is worthwhile examining the foliage on your leeks to try and detect

pupae that can be destroyed by hand removal before the adult moths emerge.

There is currently no effective pesticide available to amateur gardeners

that is approved for use against pests on leeks and onions. In the absence

of pesticides, gardeners have to either tolerate the damage or they can

try and protect the plants by growing them under the cover of an insect

barrier net, such as ‘Enviromesh’ from May onwards. This is a small mesh

material, which allows light and water through but will exclude most

pests, including the egg-laying females of the leek moth. The egg-laying

period of the second generation of moths comes to an end in late August,

 

im digging my leeks up tomorrow as the damage from another leek moth attack is terrible. i hope to salvage some and freeze them.