I have no experience with worm-farm, but insects are normal in outdoor bins. Hopefully it is in the shade and not too close to the house.

Everything that is living will eventually die and be eaten by something, that will eventually die and be eaten by something, etc, etc.

Insects are part of that process. What is the particular problem you're having?

I don't particularly like my compost materials going to feed insects, unless I have a use for those insects such as chicken feed. For now I settle for knowing that spiders have a good haven from which to spread out and control insects away from my bin.

If there is a specific insect causing actual problems, one thing you can do is get the bin off the ground and put its feet in containers of water because bugs avoid swimming.

A 'desperate measures' method of reducing the bug population in a bin is to put lots of water in it. The worms can go down in the wet bedding, but the bugs will come to the surface to escape the flood. At this point you sweep a blowtorch over the surface to flash-burn the wings and legs off of the insects. Unless you simply wish to do this for some kind of strange entertainment, there really shouldn't be any need for it if you are using basic bin care methods. If insects are just a psychological strain, then living with them is good therapy.

Bugs are a part of the normal cleaning crew in nature and you will find them in an outdoors bin. Now in an indoors bin, you may want to bake all of the ingredients you brought in from outside to sterilize them before putting them in your bin. A cardboard box that you found in your basement may have roach or pillbug eggs in it, etc.

Thanks for the helpful input. I think I read someplace that insects will gradually abandon a "healthy" worm composting operation. From that, I jumped to the, perhaps erroneous conclusion, that insects are not good. But Buckstarchaser, your comments are reassuring and certainly consonant with a live and let live stance toward critters in general. Stuff like capturing and releasing bugs in the house rather than needlessly killing them. And they do seem to be getting along fine with my wigglers.