My main concern is with the design of the screened bottom board that I've been using. I have been using the type of screen that sits on top of the base board and which also allows a sticky board to be slid between the two sections. I removed this bottom board when I installed the West Trap and when I took this apart for cleaning I found a very large number of beetles and their larvae hiding under this screen. YUK!
Maybe this is where the beetles have been breeding, because I couldn't see larvae anywhere in the hive! So I'm not very happy with the bottom board as there are spaces and crevices where the beetles can hide and breed without being harassed by bees. I will not use this type again. I've nothing against using screened bottom boards; indeed I plan to add a screen to the bottom of my existing base boards. It's just that the type that allows you to slide a sticky board between the baseboard and the screen seems to be a bit of a safe haven for pests. In future I will only use this screen when I want to use a sticky board i.e. as a temporary measure.