In order to try to maintain an insect free environment in our greenhouses and growth chambers, I have put together a Standard Operating Procedure for entry into these areas. The general rule is you should go from the cleanest, most insect free area, to one that has been determined to have some insect activity. Then once your work has been completed, or you must enter another greenhouse, you do not reenter the one you exited.
Since the basement contains some of the most important transposants, this should always be the first room that you enter. However, if you have work in both the Den and the basement, then the Den would be the first. If you have been in the field, the Delbruck basement or anywhere else at the farm, you cannot go in either. After your work is completed, you can then go to another area. Since the crop that is being grown in the other areas changes every four months, this entry order will change as the insect pressure increases. The current entry order will be posted at the WPS central posting area at the farm. A good thing to keep in mind is that maize is an insect magnet and anywhere it is grown it will eventually attract some insects so enter this area last.
I have also used a modified version of this S.O.P. in the U.A.F. and the Den. The very top shelves are used only for germination and them moved down to the lower shelves as the plants mature. The idea is to have the flats that are the oldest and are senescing on the bottom so the seed does not rain on the shelves below.