3.2.4 Pest management

Background

Herbarium specimens and printed material are subject to degradation by vermin, insect and fungal attack unless suitable preventative measures are taken. The Herbarium buildings are relatively well sealed and the environment is controlled by airconditioners to a stable 20 degrees Celsius and 50 per cent or less relative humidity; this regime is considered to discourage the growth of fungi and insect populations.

Some insects, such as psocids, tobacco beetles, silverfish and cockroaches, are known to be common in stored plant material such as is found in herbaria. In order to curb explosions in insect numbers buildings are fumigated on a regular basis. Fumigants such as ethylene dioxide, methyl bromide organic phosphates and phosphorus hydride are used in some herbaria but, because of environmental and occupational health and safety concerns and the impracticality of completely sealing the building, only pyrethrin-based fumigants are used at the Gardens.

In order to reduce the need for frequent fumigations, strict quarantine and decontamination of specimens entering the buildings is employed. This involves freezing at temperatures of less than -18 degrees Celsius for at least two days, which is sufficient to kill insect pests and their eggs. If specimens are needed urgently for comparison they are treated in a microwave oven to kill insects and their eggs.

Management prescriptions

Objective

The objective is to ensure the safety of the collection from insect and fungal damage through procedures hostile to the entry, growth and propagation of these organisms.

Implementation

The collection will be stored in a secure, weatherproof, air-conditioned, and thermostatically and humidistatically controlled environment. Strict hygiene will provide the basis for insect control, and provision will be made for periodic insect fumigation with `environmentally friendly' fumigants.

Standard quarantine procedures, meeting Australian Quarantine Inspection Service specifications for the control of insects, will be applied to specimens entering the collection. Freezers will be inspected and certified annually by officers of the Australian Quarantine Inspection Service.