Herbarium

Lea Dauwalder <lea.dauwalder [at] hkb__bfh__ch> writes

>... I would like to collect
>experiences of conservators having already dealt with the problem of
>preserving herbal material, especially herbaria in book form. So if
>you have experience with the following problems, I would be very
>grateful to read about the solutions you chose:
>
>    ...
>

>    Pest control and treatment (also the handling of objects which
>    may have been treated in the past with harmful pesticides)

Over the past 20 years I have seen numerous cases of pest
infestations of herbaria. Some were small collections, such as a
book with mounted/pressed flowers from the Middle East, while others
have been the widespread infestation of large herbariums with tens
of thousands of specimens.

The two major pests that I've found are the Herbarium Beetle
(Stegobium panaceum) and the Cigarette Beetle (Lasioderma
serricorne).

We have tried a number of approaches to slow the spread of the
infestation and damage, including reducing the temperature in
storage areas and widespread pheromone trapping.

Pesticide applications using residual sprays and insect growth
regulators have also been used in storage areas, but as the pests
are feeding within material which is also inside a bag or box, the
treatment only affects a small number insects.

The most successful approach has been the treatment of infested
material via freezing (-18C for 3+ days), and some specimens were
treated with low oxygen (sealed in high-barrier bags with oxygen
scavenger).

I have some photos of the damage that I could send if you like?

Alex Roach
Heritage Pest Management


                                  ***
                  Conservation DistList Instance 25:20
                Distributed: Wednesday, October 19, 2011
                       Message Id: cdl-25-20-005
                                  ***