Yellow and black caterpillar

[oakwoodbank]

Originally Posted by aeshna5

The stripey Cinnabar caterpillars will only feed on ragwort species (including Groundsel) so any other garden plants are safe. Peronally I'd leave the Ragwort for the Cinnabars to chomp.

Yes it is quite safe to leave the ragwort in your garden, the dangers to domesticated animals comes from it being left to grow in pasture fields.

Details on its treatment can be seen at:

CEE Systematic Review - Effectiveness of the Control of Ragwort (Senecio) Species: Are Currently Recommended Herbicides Effective for Control of Ragwort Species?

where there is a link to the full paper if you want to go that far.

From the other aspect:

It is reported that cinnabar moth numbers have fallen by 83% in the last 35 years, possibly due to the eradication of its food plant in livestock fields.

Another authority states:

"The caterpillars are also cannibalistic which is not always caused by a lack of food, although a large infestation can strip the plants of their foliage."


Another interesting fact is:

Fully fed larvae often migrate some distance before pupation . They select a dry, sheltered place usually close to the ground, such as in or under a dead log.Pupae are sometimes parasitised by the ichneumonid wasp Echthromorpha intricatoria.

And

Very few often survive to the pupae stage mainly due to them completely consuming the food source before reaching maturity, this could be a possible explanation for their tendency to engage in seemingly random cannibalistic behaviour, as many will die from starvation

So it would seem that the reduction in numbers is not just down to the control of ragwort.

Also:

Extensive defoliation and defloration by cinnabar moth caterpillars may induce plants that would have died at the end of their second year to become perennial, as can happen with plants that have been mown. When plants are under stress from other causes such as drought, feeding by cinnabar moth caterpillars may kill them.

Finally, the cinnabar is being used to control ragwort in some areas by the use of the Cinnabar Breeding Capsule. See

Breeding Capsule

[Miss Caretaker]

Wow, that breeding capsule is a great idea! I wonder if you can buy them individually or in smaller quantities. We have a small stand of ragwort in our school wild garden and it would be lovely to introduce the Cinnabar to our grounds. I finally saw a cinnabar cat. here last week (first one I've seen for a few years) so perhaps they'll find their own way in.
Jo

[oakwoodbank]

Originally Posted by Miss Caretaker

Wow, that breeding capsule is a great idea! I wonder if you can buy them individually or in smaller quantities. We have a small stand of ragwort in our school wild garden and it would be lovely to introduce the Cinnabar to our grounds. Jo

If you return to the note and link you will find that you can contact the organisation. It may be able to help you with a supply of the breeding capsules.

Just as an addenda to this thread, whilst out walking our dog today I noticed that the ragwort flowers were playing host to gatekeeper butterflies.

http://i.ytimg.com/vi/583go8j5Zbs/0.jpg

UK Butterflies
The video is not showing the butterfly on ragwort but on what I suspect is one of the thistles.

[Soosie]

Ragwort comes again and again in my sandy lawn here in nottingham and this year in the untouched corners Ive left my battle with it un won as its covered in hordes of yellow and black caterpillar. Thats all it takes a few plants round the edges of each garden corner

[oakwoodbank]

Originally Posted by Soosie

Ragwort comes again and again in my sandy lawn here in nottingham and this year in the untouched corners Ive left my battle with it un won as its covered in hordes of yellow and black caterpillar. Thats all it takes a few plants round the edges of each garden corner

Soosie
If you want to have ragwort in your garden that is fine, but I would suggest that you don't let the flowers seed in case they then infiltrate areas where ragwort is not welcome.

Incidentally, following the very severe winter here in Anglesey (the worst for forty years I was told) there has been a scenic change this year in the prominence of various species of wild flowers. Some, that previously were common, have had a reduced appearance and others visa versa. Ragwort is almost absent compared to previous years and I don't think that is due to the hand of man (directly).

[jamestsa]

We have 1000's of these lovely things where we live (Farnham). My mum however wants to exterminate them and so is calling defra to get them and remove the ragwort. I have told her I think its a little harsh, but she isn't listening to me...... bitch!!

[WhiskyBottle]

Plenty on a disused industrial site in the south west last weekend.
This one seemed to like the flowers.

[oakwoodbank]

Originally Posted by jamestsa

We have 1000's of these lovely things where we live (Farnham). My mum however wants to exterminate them and so is calling defra to get them and remove the ragwort. I have told her I think its a little harsh, but she isn't listening to me...... bitch!!

Why not ask her to await the catapillars departure before seeking to have the ragwort removed?

[soyabean]

I've seen lots of these in and around Huddersfield over the last couple of months. They were a staple in my chilhood garden too.

Someone who lives a few doors down from me has some ragwort in her garden - teaming with cinnabar caterpillars. How easily does it self seed if I were to collect some from the plant when the time comes?

I have a few large planters and tubs set aside for nettles and other wild flowers / weeds and wonder if ragwort would do well in one.

[oakwoodbank]

Dig up some of theses plants whilst they are in flower and plant them into a pot. Although the plants themselves may not survive totally they probably will survive long enough for the seed to fall and you will have new plants next year.
See:
Buglife | Ragwort | Ragwort Fact File