Curation of fungal animal pathogens

[Richard A. Humber]

Michael Chamberland recently wrote (in part):

        "I am unsure of methods for handling and storing fungal animal
        pathogens, and I am not sure if they even belong in a traditional
        "plant herbarium". Certainly, a line must be drawn when it comes
        to fungal human pathogens.

        How inclusive should be a herbarium's fungal collections?  Can
        animal pathogens be preserved in an innocuous form (ie. dried
        agar cultures) which can be mounted in packets and curated as
        herbarium sheets?"

The answer to this is that fungal pathogens of insects and other invertebrates
can easily be handled as if they were standard botanical collections. There are
large numbers of such packets mounte on sheets or small boxes containing
the actual specimens of infected hosts and/or dried cultures stored in many
general herbaria around the world. A few of these major herbaria with
important holdings of entomopathogenic fungi include FH, BPI, K, IMI, CUP,
TNS, and CBS. The inclusion of infected insects, mites, spiders, and other
invertebrates in standard plant or fungal herbaria is complementary to the
working interests of many mycologists and of mycology as a discipline; such
specimens will usually be better preserved and more useful in fungal/plant
herbaria than if placed in entomological collections.

Entomological museum collections do often include a few pinned, labelled
examples of fungus-infected insects although their presence is probably
just as often inadvertant as intentional. I am not aware of any insect
collections with really major holdings of diseased specimens; it appears
that these 'abnormal' specimens tend to be culled rather than accessioned.
Nonetheless, I am aware of one scientist who routinely did some very
effective 'collecting' for one genus of fungal pathogens by checking museum
collections of cicadas.

Issues about the safety to humans of handling fungal pathogens of
invertebrates are fundamentally insignificant even though many specimens of
such fungi, especially entomopathogenic hyphomycetes, may retain some
viability for weeks or a few months after their collection. These fungi
exhibit a high degree of specificity for their invertebrate hosts and have
an excellent record of safety for humans.

Obviously, the policy decisions about how inclusive any specific fungal
herbarium should be must be made by individual curators and their advisory
bodies. There is no technical reason why fungal pathogens of invertebrates
cannot or should not be handled and stored in the same way as more familiar
collections of fungi and plant materials. Concerned skepticism would be
both natural and appropriate for any herbarium curator asked to accession
specimens of microbial pathogens of humans or other vertebrates, especially
if these specimens were _not_ prepared microscope slides or immersed in
alcohol or formalin. Specimens of microbial pathogens of vertebrates would
almost certainly be better served and, ultimately, more useful if they were
stored by museum or medical collections specializing in the affected
vertebrate hosts.

Richard A. Humber, Curator

   USDA-ARS Collection of Entomopathogenic Fungal Cultures
   US Plant, Soil & Nutrition Laboratory
   Tower Road
   Ithaca, NY 14853