Showing posts with label slugs. Show all posts
Showing posts with label slugs. Show all posts

Sunday, August 12, 2012

Sharing With the Pests

When I was a kid I once threw a huge flip because the homegrown pear I was eating had a dead wasp in it. A big huge bite uncovered the expired intruder deep in his fruity tomb.




My grandad, who had grown up in the countryside, was far less squeamish about insects and bugs. He reprimanded me for being such a sissy (as gnarly grandfathers are wont to do) and took out his trusty pen knife to shuck away the damaged part of the pear - handing the rest of it back to me to finish eating it - which I did, albeit in somewhat more cautious bites.

He had a point. Over the years our attitude to pest damaged food has become quite ridiculous. In the west we simply throw anything away that has a nibble - be it holey greens or part fouled fruit. 

Inspecting the strawberries for pest damage.
However recent scientific research has shown that nibbled and holey greens contain additional chemicals which have been generated by the plant itself in order to fend off pest attacks. It turns out that these chemicals contain anti oxidants which are of particular benefit to humans when we eat these "holey" foods. So pre- nibbled food might actually far better for you.


Nibbled plants also produce chemicals to attract predatory insects - greens being mauled by caterpillars will eventually exude a substance which attracts wasps, which in turn eat the caterpillars.



This year we've had to share our strawberries with the slugs in a big way. It's been a bumper year for slugs in Ireland. I've never seen so many, in such large sizes and in so many different varieties. I think there's good evidence to suggest that this time they may have overpopulated.

"Ow, ow, owww!" Desperate slugs sliding over dry gravel yesterday.
They seem particularly desperate for food. I've watched them nibbling at greens they've never bothered with before, notably the leaves of foxgloves. I've also seen them moving in dry conditions, perhaps in an attempt to get ahead of the posse in the hunt for food. I've seen them eating one another, as I mentioned in a previous recent post. I'm seeing them travel over surfaces they normally avoid - over dry gravel and across the bristles of horse hair mats.  I've even seen them moving along the washing line suspended high in the air.


The slug plague hasn't boded well for my strawberries which have just faded out of season. This year they fruited extremely well, but the slugs have put big holes in at least half of the fruits. My one-and-a-half year old son loves his strawberries and regularly makes his way to the strawberry patch to raid it. So slug pellets are out.

Our other big strawberry pest is on the mooch...
With about half of the fruit ending up holey and a quarter of them about 50pc eaten, the temptation is to throw the damaged fruit into the compost bin. But that's just too much wastage for me to countenance.

In our household at least, they get washed and the holed parts are cut away so all surfaces have been cleared of areas which have had contact with the pests. Usually I end up with a clean half or a quarter fruit each time, which is better than nothing. It means I can save about a quarter of the crop by weight overall that would ordinarily get thrown away. 

I also leave some of the larger holed behind fruit on the plants to give the slugs an easy target and to act as a decoy from the soon-to-ripen fruits.

Last year it was vine weevils, this year it is slugs, next year it will no doubt be the birds or something else. There's always something. And while we'll always do our best to minimise the damage, we also have to accept that pest spoil is a fact of life with home grown food. So let's not defeat our own efforts by consigning every pre-nibbled example to the compost.
Nibbled and mauled but still usable

In contrast, today I picked some berries from a completely untouched strawberry plant located elsewhere in my garden. There were four or five juicy fruits, albeit small ones, which had not been molested by the slugs at all. 

So what's the difference between this plant and my other strawberries? 

The latter is in fact a "wild" strawberry variety of the sort that has been growing free in Irish and European temperate woodlands for thousands of years. The slug hammered varieties (see the picture above) - are all from the most commonly grown commercial varieties in Europe (like Elsanta) which happen to have their relatively recent origins in the USA and South America. These have only arrived here in the last few hundred years.

 What it does illustrate is that mother nature has provided the local varieties with all the necessary defenses against the slimy predators. Which of course begs the question: Why do we bother at all growing "higher yielding" imported varieties that can't defend themselves - especially if we either end up losing most them to pests or else spending huge amounts on pest control? Perhaps wild strawberries demonstrate that the answer to proper pest control might just have been on our doorstep all along.


Wild boys! Too much for gravel hardened slugs to handle..




Wednesday, July 4, 2012

Slug Explosions - Why Other Slugs Eat Them

The other day I stepped on a slug on the patio. The slimer did exactly what any one of us might do if something  638,888.889 times heavier than us had accidentally stepped on us - it exploded.
Sadly - the fact of having the great and accessible powers of Dr Interweb at your fingertips in the modern age means you can't just be curious about one of those obscure and ridiculous fleeting thoughts that comes into your head (in this case: "Oh, I wonder how many times heavier I am than a slug?") and then move on sensibly (as nature intended). 

No siree - seeing that I had the great online collective world brain right at my fingertips to go poking into -  I just had to go and find out.

I came back to this blog half an hour later feeling simultaneously proud and embarrassed that I had actually taken the trouble to work it out. But seeing I did it, you were dang well going to get the right number - six hundred and thirty eight thousand, eight hundred and eighty eight point eight eight nine times heavier. I am six hundred and thirty eight thousand, eight hundred and eighty eight point eight nine times heavier than an average garden slug.
Dr Interweb's Mighty Brain yesterday
But I took the long way around.

When I keyed in my question "How much does a slug weigh?" I soon discovered I wasn't alone. There were lots of people like me on the web asking this very question.

Unfortunately no one online ever seems to taken the trouble to coax an invertebrate up on a scales - understandable perhaps given that you don't really want them sliming about on your kitchen weighing system. You could perhaps try guessing it's weight, but guessing a beast's weight is all a bit too small town country fair for me. Oddly, plenty of people have weighed garden snails.

The question did produce an equation from Wiki answers. There's even a formula to show what one slug equals and another to show how one slug fits into 1lb f whatever that is.


1\,\text{slug} =1\,\frac{\text{lb}_F\cdot\text{s}^2}{\text{ft}}
\qquad\Longleftrightarrow\qquad
1\,\text{lb}_F = 1\,\frac{\text{slug}\cdot\text{ft}}{\text{s}^2}

Unfortunately, as well as being a land crawling invertebrate, a quick drink from someone's hip flask, and a spent lead bullet, a slug just had to be a measurement of mass, thus making my search considerably more discerning.

Finally I uncovered a clue - that the average crawler can eat 60mg in one go - about 40pc of its equivalent body weight.

From this I worked out its actual weight, converted mine into mgs and then divided one into the other to come up with the answer (Yes I should get out more often - but I have kids - what's your excuse?).

What relevance does this have to the story?

None. But this is my blog. 

Back to where I was.

It exploded. But when I came back that way later I discovered three slugs of various sizes chowing down on the splatted carcass. Not only that, there were many more slugs from five or six feet (miles to them) away, with the foot to floor in a bid to get there before all the dead slug debris was gone.

Having lived in a wet green country all my life and gardened for most of it, I'd never seen such a phenomenon - cannibal slugs!!

A slug having a friend around for dinner
Since then I've seen the same thing happen a couple of times - perhaps because I was watching out for it.

So I looked it up again on the internet. This time the results came quicker. And yes indeed, slugs do like to tuck into one another - though in almost all cases on already dead slugs.

It's just a pity the birds don't seem to be eating them this year because the garden is overrun with them. I planted marigolds to keep pests down and the slugs ate them! There are squillions of the little gets and I've gone nuclear with the nasty blue pellets which I absolutely hate to reach for, but without them there'd be nothing standing in the garden. I've even seen the slugs chowing down on the leaves of my Foxgloves, which I don't remember them ever doing before. I planted marigolds just to help keep the pests away - but the slugs ate them too.

There were more Marigolds in this picture earlier....

Yes I know, beer traps. Great if you can afford to give yours to the gastropods and you still have to empty the beer/slug muck afterwards. No thanks. And those white pellets which are supposed to be environmentally friendly and child safe - they just dissolve at the first drop of rain.

I've a better idea again, based on what I've learned.

So now another one of those thoughts has come into my head. It's a new slug trap which I think I'll patent. Essentially it's a big hob nailed boot attached to a mechanised arm and a timer which drops the boot to the ground and raises it again every half hour.

It works like this: Stick one squashed slug under your boot, set the timer and leave. Along comes three more slugs to tuck in. On the half hour the boot falls, clobbers the three and raises again, thus attracting more slugs and so on it goes until your garden is clear.

At least that's how it works in theory......

Now see if you can work out how much I weigh. The first correct answer in comments wins the prototype - after I've made my millions.