Garden spider and cabbage white caterpillar

[shushkin!]

Hi

I have some broccoli plants and the cabbage whites got to them!
The thing is I have noticed that there is now a garden spider under most leaves
and wondered if they are doing a bit of pest control for me as I was of course
expecting a complete wipe out in a matter of days.
Are garden spiders doing the business for me or is it wishful thinking?
Have other grapes on here
had similar experience of this?

[Demeter]

I have a lot of spiders on my gooseberry bush (which suffered a lot with 2 sawfly attacks this year) and decided to leave them in case they were eating the grubs. Mind, I've a lot of caterpillars on the brassicas and haven't noticed many spiders there. Not sure how a spider would catch a caterpillar or grub in its web? Shrug. No idea - I just leave them on principle, since they don't eat plants...

[Cloud]

You have got to check this out.I have just spent the last30 mins looking at it!Spiders - UK Safari

[Two_Sheds]

if you don't remove the caterpillars, you won't get any brassicas. They are voracious feeders.

[Demeter]

Sometimes you just can't spot them all though!
Would be nice to think of spidey lending a hand...

[Cloud]

And I found thisLarge White Butterflies - Pieris brassicae - UK Safari

[Demeter]

It says: "The caterpillars feed on brassicas. The leaves of these plants contain high concentrations of 'sinigrin' or mustard oil. These toxic oils accumulate in the caterpillars body and deter predators from eating them."

That probably rules out the spidey theory then - oh well, it was a nice idea while it lasted!

[shushkin!]

Thanks for info everyone (especially Demeter of course!) for the info
Darned, I was hoping the spiders might be helping me out. Still, I dont
know what they are all hanging about there for! They are all the same type
of spider. They are the ghostly white ones.
Like you said it is near impossible to remove everyone of the little blighters.
They are so well camouflaged.
A glimmer of hope sadly fades...

[Demeter]

On the other hand:

"Don't remove dead older caterpillars that have become parasitised because these will produce many more parasites that will attack and kill further generations of caterpillars...Transfer any parasitised caterpillars to plants where new caterpillar infestations are expected."

This is from BBC - Gardening - Advice - Non interactive Pest and Disease Identifier

Of course, I've no idea how you tell a parasitised dead caterpillar from any other kind of dead caterpillar, but found a few dead ones on my kale earlier on and left them in hope. It must have died of something, right? - so I reckon if it's dead I might as well leave it on the plant, cos I might be in luck

[Hashette]

Is there any way of getting rid of caterpillars that doesn't involve using hideous chemicals? I had a look in the garden centre and all I could find was something that seemed to be the garden equivalent of napalm - the instructions on the back waffled on threateningly for most of the packaging in very small type, and if you ask me it basically boiled down to "do not use". Sound advice from the sound of it, so I won't.

Is there any alternative to getting up early in the morning, picking the caterpillars off and slinging them over the fence?

[Sue]

Hi
I've seen those very white spiders and once I found one grasping a fly that was bigger than itself, I don't think they're web builders they are hunters on the prowl so might go after nasties?
Sue

[girl47]

Caterpillars have eaten all the foliage off my Brussel Sprouts ( first time grown ). Will the core of the plants be ok - can I expect any sprouts later in the year - or should I just give in & pull them up?
Gill

[zazen999]

Look for garlic and chilli spray on here; it's excellent.

[girl47]

Garlic & Chilli Spray? ...had a look at your link, but cant find it???

[MaureenHall]

Garlic & chilli spray - basically chop up 2 garlic bulbs and chillies, boil in 2 litres of water for about 20 minutes, add some chilli powder if you haven't any chillies, strain the liquid, then use about 1 tablespoonful to the watering can and water the plants as usual. I put the diluted solution into a spray bottle so I can squirt on the underside of the leaves. You need to give the leaves a good soaking on a dry day so the liquid dries on the leaves. I repeat as and when I remember