Well, if you did not have your entrance blocks in place it is hardly surprising that wasps have gained access.What do you mean by a wasp trap how do I go about setting one in place.
I bought one of these last year when I was suffering devastating attacks on my hives. I did not find it any more effective than jam jars with jam solution inside and pierced lids - therefore a total waste of money.I have been talking about this problem with a master bee keeper who reccomends a product called waspbane. I have ordered some of these wasp traps and will update you on their success.
Has anyone on the forum used this or any other wasp trap and if so how successfull were they