QUESTION:

My local courthouse has a heavy infestation of roaches in the ceiling. The building is 10,000 square feet and has a drop ceiling with the wiring and plumbing in the ceiling. There is access to the ceiling but not enough room to walk in. The spraying of the ground floors are not doing the trick. Should I try fogging the ceiling? Any suggestions?

ANSWER:

It would seem to me that these roaches must be leaving that drop ceiling to find food, as there really wouldn't (shouldn't ?) be anything up there that is very tasty or nutritious for them. I'm assuming these must be German roaches, but if they are not then you should make the positive ID so that any oddities in their life style could be figured out. Even German roaches would much rather live closer to moisture sources, and a drop ceiling would be an odd place for them if they don't seem to be anywhere else. Perhaps these are Brown Banded roaches?

A drop ceiling would not be considered to be a good "void" with respect to treating with dusts. Even if you used an inorganic dust like diatomaceous earth or silica gel I'd be concerned that dust could begin to sift down into the court room itself. However, if the dust could be applied as lightly as is suggested, meaning such a light layer that you can barely see it on the surface afterward, this might still be one option. Another could be the use of bait products, and again you'd prefer something that would not fall out if any of the ceiling panels is removed and tilted. Baits could be used within stations or gel baits might be placed.

But, I hate to suggest that all you do is treat the drop ceiling area, as this means that somehow the root of the problem is not being addressed. It should be determined just where these roaches are coming from, and this could lead you to a source that could then be treated effectively as well as putting a stop to any new entry of the roaches. If all you do is to treat then you may end up having to do it indefinitely, and this is not what you want. If these are larger roaches like American roaches then they could be entering from the exterior, and treating the exterior and doing exclusion could be helpful. If they are Germans then they must be going to other places to find food, and you can work to control them at those places. Germans need moisture, so is there a moisture source for them up in the ceiling area?

Fogging would kill a bunch of roaches, but fogging normally is relegated to pyrethrum products, and these leave no residual effect. You kill what bugs are exposed at that time and those in hiding are not affected, continuing the problem. Perhaps place insect glue traps in various locations in the ceiling to see if you can narrow down where they may be concentrated, and focus on that location more. A courthouse should not have any good food resources available for roaches unless there also is a kitchen, and if there is a kitchen I sure would expect the roaches to be more common there than in that dry drop ceiling.

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