The process they use still requires the caterpillar to live? (kinda) and eat more of your brassica. Their advantage comes next, when they don't allow the caterpillar to pupate, instead, the wasp larvae emerge from the host caterpillar forming their own clump of cocoons (I assume they are called cocoons).
In the photo below, you can see the victim caterpillar on left (hanging) just after the parasite wasp larvae have emerged, and on the right, wasps emerging from the slightly older cocoons. The original host caterpillar for these ones would be long gone.
The following National Geo article link describes the process in more detail as well as adding another surprising and neutralising layer of parasitic attack against the wasps themselves!
The wasps in the photo are not a hyperparasite that the article is named after (although Cotesia glomerata is the victim of the next layer/tier predator wasp).
Gruesome but I won't be shedding any tears for those caterpillar pests
Joseph posted a photo or photos with this kind of bio control. Link to one pic, could be more worth a look.
Thanks Elaine, definitely worth it, great pics!
Here's Lissa's posting the next year... apanteles glomeratus wasp.
Thanks for sharing, I found it very interesting reading Rob. There are three other Predatory Insects I know of, being - Native Parasitic Wasp, Apanteles sp. and 2 Flies, Bracnid and Tachonid Fly, they are both attracted to Herbs with an Aniseed or other Strong Scented Herbs, they are especially attracted to Sage. Thyme, Dill, Rosemary, Parsley and Fennel. If possible it is a good idea to plant any of these Herbs around your Cabbages to help Deter the Moths.
What we call 'Nasturtium' Tropeolum majus is a trap crop for the Cabbage White Butterfly. They are still buzzing around the Nasturtiums which are growing in the shade even now. There are no cabbage-family plants growing currently in my yard. Downside is that Nasturtium is a cool-weather plant and the Cabbage White rarely visits in the winter.
Another Companion Plant for Cabbages, I don't know why I forgot to list this one as I wrote an entry for it is the Companion Planting Group today, The plant is Hyssop (Hyssopus officinalis), It's a lovely plant and kids would love the pretty Blue flowers and they are edible.
Without choice I always now grow the horned cucumber and for anyone that has also grown them will know what I am talking about.I had an extreme prolific crop once and after getting an initial early harvest caterpillars invaded and I thought the vine was finished. I thought I would leave it to nature and after a few weeks those parasitic wasps moved in, flying constant aerial patrols above the vine.They done their job on the caterpillars and I got another huge crop.They really are effective littlle creatures would anyone like some seeds?
I like the wording 'without choice' Darren... a 3rd generation of plants are coming up in random locations, from an original unknown source. The one(s) allowed to stay in the ground make great volunteer vines.
That horned melon is something else Rob I only wish the other cukes would grow the same only needing to keep one vine though.,the chooks feed on ones you missed and spread the seed everywhere fertilising also for you.
Scratching my head over how the seed arrived here, I must ask myself... What came first? The chicken or the seed :)