Caterpillars on parsnip foliage.

[Anne WoodParticipant]

My parsnips have suddenly developed brown dry patches on the foliage. Checking underneath the leaf there are lots of small caterpillars eating their way through the foliage. Worse still they have started on the foliage of the carrots (which are next to the parsnips) In future years I shall remember not to sow these two vegetables next to each other.

My garden is organic and I have just sprayed the area with savona ( which does not seem to have killed the caterpillars) I have never had this problem on parsnips before. Has anybody else had this happen? and know what moth/butterflies may have laid their eggs, and what worked to get rid of them organically. Please don’t say squash them with your fingers, I am not squeamish, there are thousands of them, it would be impossible.

Looking forward to hearing any advice

Anne

[charlesModerator]

 Anne are you near the Nrofolk Broads by any chance – I googled parsnip caterpillars and the swallowtail moth came up, which lives only in the Broads (apparently…).

What colour are the caterpillars? The last thing we need is something munching the leaves of umbellifers. It is only a few years since leek moth arrived and that has had a huge, bad impact in so many areas – many of mine are damaged already, earlier than usual.

[Anne WoodParticipant]

Thank you for your reply Charles. I live on the Essex/Suffolk border. I have not seen anything resembling a swallowtail moth, and having googled their caterpillars I don’t think they are the army that are eating my parsnips. The caterpillars on my parsnips are ( at the moment ) 5 to 10 ml long, but I suspect they will become huge if they carry on eating as ferociously as they have been. They are quiet translucent, pale green and with black heads. They eat the green underside of the leaf, which makes a brown patch of damage on the foliage.

I agree with you that leek moth is enough, we don’t want parsnip and carrot caterpillar as well!

[wendypParticipant]

I have these too, and I’m in north Dorset. I’ve never seen them before, and I wasn’t too concerned as they are on carrots which are about to be pulled, but I’m going to go out right now and check the parsnips and salsify in the same bed.

[bluebellParticipant]

I just did and apparently there is a parsnip moth. Thankfully I have never seen it be for but it does apparently have caterpillar that feed on wild parsnip….

[GinamcconMember]

I’m in mid lincolnshire. I checked my parsnips today and a few have the brown patches and as many as 5 per patch just hatched caterpillar underneath. They haven’t started munching yet.

[WillsandlandsMember]

Hi Anne, try BioBT from http://www.homeleighonline.co.uk/bio-bt-caterpillar-killer-8-sachet-pack.html See comment on Brassica piece

Will

[Anne WoodParticipant]

If you have thin brown papery patches on your parsnip leaves. I am afraid the caterpillars have started munching, they seem to eat away all the green matter underneath the leaf, just leaving the upper layer. But Willsandlands who has commented on this blog ” how to keep caterpillars off my brassicas” suggests a biological control and has left the web site address. I have ordered some immediately and am hoping this will be the answer.

[portzedMember]

Dear Anne,

We have exactly the same problem in Portishead (near Bristol).

Everyone on our 3 acre allotment has this problem with their parsnip foliage.
We have never knowingly had it in previous years.

Your description is accurate for our problem.

The only reference that I can find that resembles this caterpillar is something in the USA but they say it feeds on the flower and seeds.

I have photos of our caterpillars but I don’t yet know how to publish them on this site as I am new today.
I did reluctantly use an insecticide spray and this seemed to stop them.

Our worry with the caterpillar is will it affect the root crop.

[charlesModerator]

 Thanks for this post portzed, and welcome to the forum.

You can email me a photo to upload as it would be helpful for lots of gardeners. This caterpillar sounds bad.

By Christmas I hope the site will be upgraded and able to accept photos in the forum.

[Anne WoodParticipant]

Hi Will,

I did read your comment on ‘ how to keep caterpillars off cabbages’ and thought it might be just the job for my parsnips. My packet of BioBT arrived today and I am waiting for the rain to stop before spraying it on. Thank you so much for putting this note on the forum. Hope I have the same success that you did.

Anne

[ruth nobleParticipant]

I have them over the Irish Sea as well. Took to squashing them and the old washing up liquid trick which seemed to work if you don’t have too many. Next year, there will be hardly anything in the garden that isn’t netted beyond belief.

[charlesModerator]

 Oh dear Ruth this sounds ominous!

Here are photos sent by Portzed:

   

    

Also he says:

This year everyone on our 3 acres of allotments (Portishead) has been suffering from an infestation of caterpillars on the parsnip leaves.
It started late July and was very visible by 10th Aug.  We have not knowingly had this problem before. I have not found any textbook or internet reference to our precise problem, but there seems to be a
similar caterpillar in the USA.

Can you help us to answer the following
How do we get rid of them?
How do we prevent them in future years?
Will they spoil the root crop?

As a matter of interest Celeriac and carrots are unaffected and we have avoided carrot root fly so far…

A spray of bacillus thurigensis has been recommended here, see other posts in this thread. Maybe it means mesh over parsnip leaves from about May next year?

It must affect the roots but does anybody know how long they continue eating?

 

[Anne WoodParticipant]

Re: the photographs, yes these are the culprits that destroyed 25% of my parsnip foliage and 100% of carrot foliage.

The damage was incredibly quick, only taking a week or two to go from the best crop ever, to decimated. Strangely enough despite the quantity of leaf the caterpillars ate, they did not get any bigger. This seems impossible but is the case.

Someone wrote, on this blog, that there is a parsnip moth/butterfly in USA but it only eats wild parsnip flowers. Not the case here, they only ate the leaves ( but then my parsnips had not gone to seed)

Willsandlands (member of this blog) advised me to buy a packet of Bio BT. I sprayed it on the foliage last Sunday, it is now Thursday and the caterpillars have virtually all gone. So it took four days. I can now see new fresh green growth shooting from the base of parsnips and carrots.

I have pulled some carrots and they are sound but very small. The parsnips I have not checked and will not bother until I see what the harvest brings after a frost.

I did not water the parsnips and carrots whilst the spray was on the foliage as it washes off very easily, but now the caterpillars have gone I am feeding and watering the plants more than normal as I feel they have had an enormous check and the new green growth will also be taking more energy out of them.

Next year I shall certainly keep my eyes sharp in July to check for brown spots on foliage and always have some Bio BT at the ready.

So a big thank you to Willsandlands

Anne Wood

[GinamcconMember]

Yay, I’m glad something has worked for you, sounds like useful stuff. Interestingly I have a double bed of cabbage and parsnip covered by environmesh. Sadly a baby bunny got in about 6 weeks ago and left a hole for insects. I now have a few of these caterpillars on my parsnip but nothing on the cabbages apart from bunny nibbles, so whatever it is it was here before the cabbage whites and it doesn’t like cabbages.

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