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Q&A Special: How do you handle Pests?
Pest control has come a long way since the days
of 'carpet bombing' a building with toxic insecticides to reduce
the chance of insects damaging collections. The National Gallery
of Victoria conservation department introduced Integrated Pest Management
(IPM) in 1990 and we believe this was the first use of the technology
in Australia. IPM has since been adopted in many Australian public
buildings, especially hospitals and schools, as the preferred pest
control strategy. Before IPM, the NGV and most public buildings
in Australia used repeated spraying of the building with long lasting
residual toxic chemicals intended to kill all insects that came
into the building. Rodents were in most cases successfully baited,
but baits for insects had at that time not proved very effective.
In the 1980s in the U.S. it was recognised that long term exposure
by staff in buildings to even low levels of toxic materials could
cause severe health problems and there were significant court cases
seeking damages for illness caused by exposure to pest control chemicals.
Alternate strategies were considered, IPM emerged and, simultaneously,
general toxic spraying of all U.S. Government buildings was banned.
IPM strategy involves catagorising all insects
and other creatures as direct threats, indirect threats, or not
a threat. Traps, usually sticky traps, are regularly set and the
trapped insects identified and compared against their threat potential.
If direct threat insects are found, the area is either treated with
a nonresidual low toxicity pesticide such as pyrethrum, may
simply be cleaned, or ultraviolet light traps may be introduced
to attract and electrocute or trap the insects. Indirect threats
include insects which cause no damage, but whose dead bodies are
a food source which will attract and sustain threat insects. In
this case, the area is carefully cleaned to remove dead insects,
but poisons are not usually required. We have two influxes of bogong
moths per year which die, providing a food source for carpet beetles.
The only way to break this cycle is to promptly remove the dead
moths, which is difficult in high and hard to reach areas. We have
taken this into consideration in the design of our new building
at Federation Square and in the redevelopment of our St Kilda Road
building, briefing the architects to provide no open girders, high
ledges, or any out of reach areas where dead moths can collect.
Nonthreat species, many of which are enemies of threat species
and therefore our allies in pest reduction, are left alone.
By introducing IPM, the NGV has significantly
reduced pest control costs, enormously reduced the potential danger
to staff and visitors, and also enormously reduced its contribution
of toxic chemicals into the environment. Since introduction of IPM,
other technologies for attracting and trapping specific threat species
have evolved in the form of synthetic pheromones which either imitate
the sexual attractant of a specific species allowing all of one
or the other genders of a species to be trapped and thus not allow
a successful breeding season, or masks the sexual attractant which
then confuses suitors and again foils a successful breeding season.
This technology is rapidly emerging and, again, the NGV is one of
the first institutions to evaluate and, if successful, adopt it
to help preserve its collections for future generations.
A final note. The best defence against pest
damage to collections is to reduce the attractiveness of your building
to pests. Food waste is of critical concern and cleanliness is essential.
Kitchen waste should be cleared from the building each night. Eating
areas need to be cleaned every evening. Eating should not be allowed
in storage areas and never allow people to walk about the building
consuming food and dropping crumbs as they go. Poor housekeeping
practices can easily overshadow and render useless even a good pest
control management programme.
Thomas Dixon, Chief Conservator, National
Gallery of Victoria.
Thomas Dixon was previously Senior Lecturer in Paintings Conservation
at Canberra University. A native of the U.S.A., he worked in institutions
including the San Francisco Museum of Modern Art and Brooklyn Museum
and has consulted widely with museums in the US and Australia and
overseas. You can visit the National Gallery of Victoria at www.ngv.vic.gov.au
or call 9208 0222.
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