At our GIY meeting today at Sarah’s house (thank you for the lovely tea Sarah!) we wandered on to her allotment lamenting the huge amount of blackfly which are devastating everyone’s crops, especially beans.
“Where are the ladybirds this year?” we asked each other.
Well, they were all over Sarah’s broad beans! It seems we have had a timely explosion of the ladybird population this week.
On my runner beans this morning I found all 4 stages of the life cycle on one plant – eggs, larva, pupa and adults. In the photo with lots of ladybirds you can see pupa cases, some empty, plus active adults. The other one shows an adult and larva. Also this picture gives a clear view of the adult ladybird’s legs – a clue as to its origin.
We found about six different forms of the adults on these beans, some with brown legs and some with black legs. The ones with black legs are usually our native species, while brown legged ones indicate the foreign Harlequins, which are quite aggressive and will eat the native larvae. However, they all eat aphids and it is advised by the conservation organisations that we don’t try to kill the Harlequins. I suppose because we might get it wrong and it’s rather a futile task anyway!
The colouring of the wings and size of the insect is only an indication of different species or forms, not ethnicity. I have been spraying my beans with dilute washing up liquid, which kills some of the blackfly but I think I’ll stop now and let the ladybirds get on with it.