ENHANCING THE EFFECTIVENESS OF MODIFIED ATMOSPHERES TO CONTROL INSECT PESTS IN MUSEUMS AND SIMILAR SENSITIVE AREAS

Abstract-Anoxia resulting from contained atmospheres of ~ 0. 1 % oxygen (1,000 ppm) was lethal to all stadia of a variety of insect pests commonly encountered in museums and other sensitive areas. Low % 0 2 in a closed system was achieved and maintained by displacement with gaseous nitrogen. The effect of anoxia on representative species of cockroaches (Dictyoptera), fabric beetles (Dermestidae), stored product beetles (Anobiidae), termites (Rhinotermitidae), and wood-boring beetles (Lyctidae) was evaluated. Most insects succumbed within hours or a few days exposure. A few, such as larval carpet beetles, Anthrenus fluvipes, eggs of cigarette beetles, Lasiocierme serrico2ne, and powderpost beetles, Lycfus spp, survived>8-day expoiure. Length of exposure for mortality (LT) appeared to be related to metabolic rate and to the ability of the exposed stage to regulate water loss. In this regard, LT was generally inversely correlated to % 0 2 and to exposure temperature and relative humidity. Increasing 0 2 to 0.32 % increased time for LT for some species but not for others. Increasing 0 2 to 0.62 % approximately doubled LT. Adding C02 during anoxic exposure reduced LT, apparently by increasing futile metabolism. It was difficult and relatively costly to maintain <0.1 % 0 2. Higher 0 2 rates may be practical for controlling some species if higher temperature or low humidity may be maintained. Methodology for maintaining between <0.1 % and 0.62% 0 2 is discussed