Herbarium insecticides

In the past we used paradichlorobenzene in order to prevent any insect infestations in the herbaria. This use is suggested against it due to health concerns. Any suggestions for alternative chemicals. Someone suggested camphor but I am doubtful on its effectiveness.

Dear fellows, we used sulfuryl fluoride for disinfection in Shanghai Chenshan Herbarium (CSH) by professionals.
But first of all, the environment control, like the temperature and humidity balance in the herbarium should be more concerned. Disinfection always is the last one.
Good luck!


Thanks very much for your reply. Do you fumigate on a regular basis, periodically several times a year or you only fumigate any cabinet when infestation is observed?

Dear , Sir
Hope you will b fine
following is the poisoning protocol for herbarium as well as for herbarium specimens in our Botanical garden Herbarium .

Procedure: make a solution and dip the plant specimens before add to herberia
Spray the whole herberia and as well as different herberi sections
Phenole= 1 g
mercuric chloride=1.5 or 0.5 g
D. water=1 liter
ethanol=1 ml

Rashid Afzal

Thanks appreciated you re reply, although I doubt I can use mercuric chloride over here.

We are in the Chicago region, so insect pressure is not as high as in many areas of the world. However, we discontinued chemical use at least 2-3 decades ago (before my tenure in the herbarium). We use insect traps to monitor, and we are careful about freezing any specimens for 48 hours before they go into the cabinets, and if they have been out for more than 24 hours. We also segregate our prep area in a different room, so that fresh material does not generally come into the main herbarium collections.

Thanks Andrew

Greatly appreciated

Hello and thanks for this good question. I did want to jump in and reiterate that we really want to avoid any use of mercuric chloride – this is absolutely not a safe option, nor an acceptable option for any herbarium!

Here is a link to a paper a paper describing the human health risk and very costly process of cleaning mercuric chloride contaminated specimens.

There are some additional helpful resources from MuseumPests.net and Integrated Pest Management Webinar (recorded) from ConnectingToCollections.

As Andrew mentioned, before specimens are placed in your collection, freeze them for 2-5 days at -20 C (if possible). Keep the herbarium space isolated from other work spaces. Keep the temperature low (18°C) and humidity stable (45% Relative Humidity) in the collection space. Seal the cabinet doors to prevent entry. Here at BRIT we use a pyrethrin spray for sport treatments or for items that are too large to be frozen. The cabinets are also treated every six months with a chemical called hydroprene, which is a developmental inhibitor for most insects. The brand name for the product we use is called Gentrol.

If you can’t do all of these things, do as many as you can for a complete integrated pest management best practice in your herbarium.



1 Like

Dear Morgan

Thanks very much for your detailed response… Greatly appreciated.