Black Caterpillars

[rkaiser]

Anybody notice the hoards of Black Caterpillars on the thistles these days? Seem to be more than other years.

What are they, and will they cause the old thistles and problems?

[jensend]

they are caterpillars from painted lady butterflies or moths and they can wipe out thistle patches. they might bother canola a little and will eat leaves off sunflowers. they should come up here every year but on average make it every 7 or 8 years.

[cakadu]

I was cutting the thistles down when I noticed the black catepillars myself. I also noticed that they were slowly killing the thistles as well. The catepillars themselves - I am told by the bug guy I talked with last week - will grow to about 1.5 inches when they will begin to cocoon and wait to come out again next year.

He also said that they will eat things like canola and peas if there aren't thistles around, but the thistle is their preferred food. Amen to that!!!!

[grassfarmer]

Great what nature can do if you haven't used any pesticide to kill all small critters or herbicide to kill all the "weeds".
I haven't seen any of the caterpillars up here but we are really bad with grasshoppers. I'm hoping the mosquitos might start preying on them.

[rkaiser]

Great what nature can do. But I don't like to think about what these little wonders might run in to should they reach the canola feilds.

[grefer]

We are in an area that has had large numbers of these butterflies,now worms.They don't seem to be bothering canola yet.A neighbour had some organic borage and they destroyed it.They haven't bothered my peas yet ,but they wiped out a patch of round leaved mallow.Good on them.

[whiteface]

Any of you know if they are the caterpillars I had to spray off all my Colorado Blue Spruce Trees? Literally millions of caterpillars absolutly ravishing the poor trees...
some of the trees died. Some I saved but have never had so many caterpillars in over 10 years that I've lived here and incidentally, don't ever remember seeing any of those painted lady butterflies until this year...
and then with the spruce trees. Just curious if any of you know. Thanks all and have a good day.

[grassfarmer]

It's OK rkaiser they'll probably choke on the glyphosate when they bite into the canola! If you try to grow monocultures of crops in a sterile environment the insect hordes will come and destroy you - it's natures revenge.

[cowman]

grassfarmer: I doubt you could find any traces of round up in the canola at this stage? Probably less than the amount of Ivomec in your own cattle?
I wonder if you are concerned when you eat any foods prepared with canola oil? Or for that matter cattle treated with Ivomec?