Friday, 30 May 2014

Professor Derek Knottenbelt bonkers quote on ragwort?

I  regularly blog on this issue, and those who follow me know it is a serious matter for me, but there are times when I can't help laughing.  This is an example.  I came across this stuff when I was browsing around for something else and I just burst out laughing.  The level of ignorance that it seems to show is just hilarious.  As regular readers will know, I've established by the means of rational evidence that the fuss about ragwort is clearly and unequivocally exaggerated.  In fact the evidence clearly shows that things have been made up about it.  However, this stuff is just hilariously wrong.  Perhaps it is  not quite so obvious to those people who don't study the subject, but to someone like me who would have known this was wrong at the age of seven, it is so hilariously wrong I just can't help laughing.  To put it into  context,  imagine somebody claiming that flies are poisonous to spiders, or that carrots are poisonous to rabbits.

It is also very important to realise, humour aside, that the academic concerned has been very very active in the matter of encouraging control of ragwort. He has been quoted and quoted repeatedly all over the press and giving many talks to influential people.

This claim is a quote in a book from Professor Derek Knottenbelt.  The professor is well known to people who work in the ragwort field.  Suffice it to say that the people who I deal with who are experts in the field do not seem to be particularly impressed with him.  For example, he claimed in a  letter in a newspaper that our common ragwort was causing serious problems in South Africa.  I checked with  the experts there and there doesn't seem to be any record of the plant ever growing there.

The quote is in a book called The Horse and Pony Care Bible in Association with Horse and Hound.  This book was published in 2007.  The only question I would have as a rational person is,  is the quote accurate?  I'm afraid given what I've seen the professor saying before it seems entirely credible to me.  In any case it seems to bring the book into total disrepute.  From where I'm standing no one with any proper knowledge of entomology would ever make a statement like this.

Professor Knottenbelt is quoted as saying: -
`I would not normally advocate the eradication of any species, but this one has nothing to offer. I don't accept that eradicating ragwort would eradicate the Cinnabar Moth, which feeds on it. Ragwort is burgeoning and the Cinnabar is declining. In fact, I believe it is being poisoned. The moth was common throughout the years that ragwort was rare and now that ragwort is widespread, Cinnabar Moths are difficult to find. If we care about the moth, we have to find out why its population is declining in the face of an ad lib supply of "feed'.

This seems so ridiculous to me that it  is hard to know where to begin.  The most obvious hilarious thing is of course that the Cinnabar Moth uses  ragwort as a natural food.  In fact it seems essential that the ragwort alkaloids are present in the plant to enable it to be eaten.  Without the alkaloids the moth would ignore the plant.Plants with the alkaloids are the only food. Looking at it rationally, in a calm and considered manner, the only appropriate word to describe this part of the  claim seems to be BONKERS!
It is true that the Cinnabar Moth is declining, but what is also clear from the proper government scientific survey which was actually published in the same  year,  2007, is that ragwort is also declining, and what is more,  the decline is a marked one.  The professor has been saying for many years that ragwort is increasing greatly, but all the evidence is that this is not the case.  In fact it seems absolutely clear that the reverse is the case.  Certainly having watched it for many years I can never remember a time when I ever noticed that ragwort was a rare plant.

Of course the real issue over biodiversity and ragwort is not the Cinnabar Moth, but all the other wildlife that depends on it.  It is also vitally important to realise that we know from very clear evidence from a study of population dynamics that even declines in common plants which still leave the plants relatively common can have disastrous effects on the animals which require them for food.  Indeed,  ragwort is mentioned in several of the standard textbooks on this matter.
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1 comment:

  1. Great blog. The hysteria about ragwort is really rather worrying, not helped by the low standard of most mainstream science journalism. I am becoming more and more curmudgeonly by the day.