there is a special trick to separating them out. First you take your original container of them and sift out EVERYTHING except the flour itself. However, here is the trick. Inside that flour are the eggs that you cannot see. Put some (not all, cause you will need some to keep the beetles and larvae in) of that egg containing flour into another container of some sort and put the date on it. In about 2-3 weeks, sift the flour again and you should only get larvae from that second container. You shouldn't have any adult beetles in there, if you do, start all over and this time, check it sooner. Now this second container should be considered the breeding container. You can take the first container and sift out all the beetles and larvae and put those into the second container. Then label the first container, which should only have eggs in it...... Just keep rotating the containers like this. I don't know how many cycles the cultures will last, you will probably have to get some new blood at some point. You will also want to get new flour (or whatever they use) in your cups. Soon you will learn the life cycle of the beetle and be able to plan siftings accordingly. Remember to periodically renew the eggs in flour cups.
One point to remember with flour beetles is that they make some kind of gas that is toxic to them, so never put a lid on the container, as they will suffocate. That is why my containers have a huge hole in the top. It looks more like a little lip around the edge of the cup, instead of a hole in the top.
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phflame