[Nhcoll-l] Herbarium freezing

[Hagar Leschner]

Dear Roxali,

Regarding your question about freezing herbarium specimens as means of pest control, here's the protocol of the national herbarium of the Hebrew University:
1. Specimens within the collection:
                Routine freezing in -300C for min 48h.
                Each cabinet goes under this once every 18-24 months.
                In our climate - warm and dry, this is good enough.  We never found insect contamination in 15 years of my work at the herbarium.
2. Imported specimens:
                All new material, regardless source, and returned material, goes under freezing in -800C for at least 2 weeks (340h).
                This also had proved  sufficient.
3. Exported specimens:
                All exported material goes under freezing in -800C for at least 2 weeks (340h).

The protocol is our local adaptation, a matter of "trial and error".
15 years of monitoring this protocol proved it is good even in poor conditions - until two years ago the collection was not fully insect safe, and temperatures were occasionally too high. Moreover, there is no humidity control in the herbarium hall.


With best regards,

Hagar Leschner

Collection Manager
The Herbarium of The Hebrew University (HUJ)
The National Natural History Collections at the Hebrew University
Berman bldg.
Edmond J. Safra Campus, Giv'at Ram
Jerusalem 91904
Israel

972-2-6584456

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