lifespan of cabbage white caterpiller?

[ChrisE]

I was losing the battle picking caterpillers of my cauliflowers when my wife kept telling me not to pull them up. Uncharacteristically optimistic I thought??

Then a set of three polytunnels turned up for my birthday, so I picked off all the caterpillers I could find and covered them up. It's very satisfying watching the cabbage whites bump into the polytunnel time and time again without luck.

It's now been about 5 days but I'm still finding caterpillers (large white & small white), I've assumed these were eggs or small caterpillers I hadn't removed. There bare less than before I covered them up.

So my question to the grapes, is how long does it take for a egg to to turn to caterpiller and then butterfly ? As in theory when that time has passed my cauliflowers should be bug free.

Should I get some nematodes under the poyltunnel as well? Is there any danger of plants getting to damp under a small plastic polytunnel?

thanks in advance,

Chris.

[Nicos]

Hi there...and welcome to the Vine!

I googled this about the life-cycle - if it's any use....

Cabbage caterpillar and moth pest control

[rustylady]

Long enough to make a right mess of my brassicas! Cabbage whites have been a real menace for the last few weeks and picking them off doesn't seem to have done any good, theres thousands of them on my PSB.

[Nicos]

I found this too....

Lifecycle
Duration does vary due to temperature so enclosed is a helpful guide.

Ova stage = 4-8 days

Pupae stage = 21-28 days

Larva stage = 21-28 days

Adult stage = 7-14 days


(That's at 21 C it says)

[ChrisE]

Thanks Nicos, from the 1st link you posted it looks like 5 days for eggs to hatch then up to two weeks before they pupate at which point they no longer eat the greens.

So I'll keep picking of the caterpillers for a couple of weeks yet and hope the polytunnel means no more eggs will get laid.

I also searched yahoo but didn't find that site,

thanks again,

Chris.