I am told that now the days are frosty all the bugs will get killed :BangHead: not all on my plot. We have had several hard frosts but yesterday I found these little BBBBB s.
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Songbird populations can certainly plumet in a cold spell, and they're a significant predator of caterpillars, so I could imagine that if robins, dunnocks, and tits were hit hard by the weather then some insect pests could actually do rather well out of it, and it wouldn't surprise me if cabbage white caterpillars could survive prolonged freezing quite happily - some of those critters actually have a natural antifree to keep them from dying. Pest and predators populations are essentially chaotic, so they vaguely follow some kind of discernable pattern, but their populations can also at times explode or crash, so I'm not altogether convinced that cold weather is necessarily a good thing for their control.
That said, I think it'l likely that mild winters have allowed foreign invaders to establish permanent populations here - Leek Moth is just one example - and that I think is climate change in action.
Very strange; cabbage whites should be in chrysalis over winter. I've never seen caterpillars this late. Certainly in chrysalis form, they survive frost.
Must say I have been thought to see them this late.
Yes I have one PSB plant uncovered and I thought I'd seen the last of the caterpillars on it, and it would be able to recover slowly now, but at the weekend, it had more on it again!
Very few butterflies this summer and autumn so very few caterpillars here. Those that do appear tend to get hoovered up by the birds and I've had no real problems with lacey brassicas for the last two summers. I feed the birds all year so the parents have the energy to go and find caterpillars and aphids for their broods.
A bigger problem for me this year has been the cold, wet summer producing very poor broccoli and PSB and cavolo nero.