We are in the process of fumigating some of our collections. All of the Natural History specimens that were on exhibit in the Discovery Room, as well as some taxidermied mounts (ie. stuffed animals), have been placed in our fumigation bubble to be treated. This is a regular procedure for objects that are susceptible to insect attack.
The Manitoba Museum has a large enclosure (“the bubble”) made of heavy duty plastic, with a steel frame inside, that is used to treat objects with carbon dioxide gas. The bubble is filled with carbon dioxide to at least a 60% level, to displace the oxygen. The resulting low level of oxygen, if maintained for 14 days, will kill insects at all life stages – adult, larva or egg.
Here is a picture of our fumigation bubble:
Here are the tanks of carbon dioxide:
This treatment has been conducted many times over the ten years that we’ve had the bubble in place. It is completely effective in eradicating any insects found on museum objects. The procedure is a preventive measure that is used as part of an Integrated Pest Management program, in order to keep our collections free of damage from museum pests.
Whenever circumstances pose a risk to objects, such as receipt of new acquisitions from outside, return of loans to other institutions, or removal from display in the galleries, they are put through some kind of treatment against pests. Usually, it’s freezing, which is a simple, effective way to kill insects in most circumstances. It’s not always appropriate, though. Very large objects (such as a muskox) can’t fit into any of our freezers. Thick objects also don’t freeze well, because by the time the center of the object is frozen, the insect has adapted to the temperature change and isn’t killed (they’re quite amazing that way!) Also, if we have a large number of objects, freezing isn’t logistically feasible. In these cases the fumigation bubble is ideal.