Abiotic and Biotic Factors Affect Microhabitat Selection by the Firebrat, Thermobia domestica (Packard) (Thysanura: Lepismatidae)

Abstract

Arthropod microhabitat selection involves a hierarchical assessment of abiotic and biotic factors. In choice experiments, we tested firebrat, Thermobia domestica, microhabitat preferences. Firebrats preferred elevated (35°C) over ambient (20°C) temperature, black over white shelter, and small (1 cm) over large (15.5 cm) entrance holes. Food availability did not alter shelter selection by firebrats. Medium juveniles, large juveniles and adults, in homo- and heterogeneous populations, preferred high (4.5 and 6.0 mm) over low (1.5 and 3.0 mm) shelter heights. Small juveniles, however, selected shelters with conspecifics, not by size. Females held at 35°C, but not 20 or 25°C, laid large numbers of eggs. Thus, abiotic characteristics of a shelter, coupled with the presence of conspecifics, affect microhabitat selection by firebrats. These findings may improve entrapment and management systems of firebrats.