A REVIEW OF PUBLISHED TEMPERATURES FOR THE CONTROL OF PEST INSECTS IN MUSEUMS

Reported temperatures for the extermination and control of 46 museum insect pests are tabulated and graphed. Temperature and time of exposure found in publications recommending thermal control methods for museum use are tabulated for comparison to the mortality data from entomological literature. Miscellaneous control temperatures are also tabulated, providing information on chill-coma, feeding and developmental limits. A lethal boundary model is proposed as a provisional guide to thermal extermination of insect pests. The use of thermal insect control techniques in museums and archives has been fostered by increased restrictions on, and costs of, fumigant and pesticide use. Thermal control methods are used when there is reticence to expose cultural property or museum personnel to proven or potentially deleterious chemical agents. Adoption of thermal control techniques to replace pesticides is hampered by concerns that thermal techniques will fail to control insects. These concerns are due to the lack of available data on insect susceptibility to heat and cold, an awareness of some insects' capability to survive temperature extremes, a wariness of generalizations in literature, the need for justification of capital expenditure on new equipment, and suspected or known effects on artifacts and specimens. In most of the recently published thermal control methods for museums, en­ tomological literature is sparingly cited. Many of the earlier published recom­ mendations were derived from experience with only a few species. Recommen­ dations for controlling particular insect species have also been generalized in subsequent publications, so there is a danger of failure to control a species which was not included in the original recommendation. This paper was written to address concerns rooted in the lack of comprehensive information on the thermal mortality limits of museum pest insects. Thermal mortality data are presented as a provisional guide for users of temperature ex­ tremes to control insects. The data are also provided for potential users of thermal insect control who require evidence of efficacy. Control methods from conser­ vation and museology literature are reviewed and compared to an extensive source of entomological literature on temperature sensitivity of museum pest insects. The data on thermal limits to the insects are organized in the Appendix to this paper and provided as a basis for further study or individual need. This paper is restricted to a discussion of museum pest insects and excludes theorized and described effects on materials.