Egg masses of the forest tent caterpillar, Malacosoma disstria Hübner, were collected from new and old infestation areas of northern Minnesota before development started in the spring. Mortality of embryos was recorded after laboratory exposure to −10°, −15°, −20°, −25°, and −30° C for 12, 24, and 72 hours at 1, 2, 3, and 4 days before anticipated hatch. Length of treatment and temperatures of −10° and −15°C had minimal effect on survival. Mortality of embryos varied with days before hatch in an erratic cyclic pattern with temperatures and years. Temperature treatments of −20°, −25°, and −30 °C caused about 50%, 66%, and 100% embryo mortality. Mortality in new infestation areas was consistently higher than in older areas for all treatments.

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Spatiotemporal reasoning is a fundamental contributor to effective problem solving. In an effort to design better problem-solving agents, we examined and evaluated the strategies that humans use to solve Tower Defense puzzles, a complex and popular class of real-time strategy games. A consistent and unexpected finding was that humans frequently treated time and space as equivalent. Players stated temporal goals but solved spatial problems. An analysis of human data and computer simulations showed that re-representing temporal problems as spatial problems was beneficial, but treating the two separately can lead to higher scores. The work presented here holds several possibilities for level designers and others who design and analyze maps and spatial arrangements for domains requiring strategic reasoning.

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