Figure 2.

Baseline level of escaped insects in an ACL-2 insectary. While the occasional free-flying insect will be discovered within the rearing space, such events should be progressively rarer across each barrier leading finally to the external corridor. *Note that in locations where the same or similar species occur locally, migration of wild insects from outside into the corridor, or from the corridor into the vestibule is possible. Operating procedures for such facilities must anticipate this possibility, and be sufficient to allow the unambiguous determination of changes in the frequency of insect releases.