Meeting Abstract
Several traits characterize colonial living in animals, but an especially important one is modification of environmental temperature. Colonial insects are some of the most common animals known to create structures that alter thermal conditions of the group. Because insects are ectotherms and rely on their environmental temperature to regulate body temperature and thus rates of metabolism, the ability to control environmental temperature is especially crucial. Here I describe mechanisms of thermal modification in the Western tent caterpillar, Malacosoma californicum pluviale. Tent caterpillars build communal silk tents, which can be heated to temperatures substantially above ambient air temperature. In spring 2019, I quantified how individual caterpillars are experiencing this extra heat. Using IR thermal imaging I captured body temperatures of caterpillars in the following combinations: grouped on the tent, alone on the tent, grouped off the tent, and alone off the tent. I found that caterpillars grouped together off the tent had somewhat elevated body temperatures above solo caterpillars – a result that was replicated using operative temperature models. However, grouped caterpillars on the tent reached much higher temperatures, suggesting that the tent is capturing extra heat. My data suggest that the tent plays an important role in maintaining a more buffered thermal environment for caterpillars over and above its function as a platform for behavioral thermoregulation.
