The butterflies are searching for brassica plants on which to lay their eggs, which in due course hatch out as caterpillars - the ones that can so easily decimate your crop in the space of a day or so.
My main brassica crops are covered with nets which are hopefully keeping the butterflies out, but elsewhere in the garden (as far away as possible from the main brassica crops) I have a group of spare PSB and Cabbage plants, which are unprotected.
I'm not worried if these plants don't make it. I have dubbed them "Sacrificial plants" because they can help to lure the butterflies away from the plants I want to grow. The butterflies are making the most of the opportunity, and I see that the plants are already covered in eggs.
These are the eggs of the Large White, typically laid in groups:
These are the eggs of the Small White, typically laid singly:
The eggs are white when laid, but gradually turn yellow.
I'm not sure what type of eggs these ones are. They are definitely different. Anyone know what they are?
While photographing the butterfly eggs, I noticed a small beetle-type insect on one of the leaves. At first I thought it was a desirable insect, probably a predator of butterfly eggs.
However, closer inspection suggests that this is NOT a beneficial insect. It looks like the Rape Stem Weevil Ceutorhynchus Napi. Furthermore, it was not alone - there were several of them. My photo here is not of the best quality, but I believe it demonstrates conclusively that these weevils eat the central ribs of the brassica leaves:
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| Caught red-handed! |
OK, so I think I have another task ahead of me now - picking off weevils! Perhaps I need to check my main crop plants too, since the nets covering them will evidently not keep out a 3mm weevil.
Yet another pest. I hadn't heard of those before. So many thing want to eat our gardens.
ReplyDeleteIt looks like your trap crops are doing their job well. I hope they leave your main crop alone! I have got my fabric ready to cover the brassica plants. Should I wait until they have sprouted do you think? or cover them now?
ReplyDeleteIt's never too soon to cover brassicas - I would do it now!
DeleteThat's another pest you've added to my list - although I'll need reading glasses on to find this one !
ReplyDeleteNever a dull moment in the garden---there is always something to challenge us.
ReplyDeleteI first noticed weevils in my garden this year - not on the brassicas (yet!) but there were quite a few in my strawberry patch. Don't know what kind of weevil it is, but it is a greenish colour. The strawberries themselves were ok, but the leaves are looking pretty chewed up.
ReplyDeleteThat's interesting, because I recently noticed that my Strawberry plants' leaves were very "notched" at the edges, which may be a sign that weevils are present - not something I have seen before on Strawberries.
DeleteOh dear it was just as well you were photographing the butterfly eggs otherwise the weevils may have been lying there undetected for a while. Sarah x
ReplyDelete