TOLERANCE OF THE STRIPED EARWIG (DERMAPTERA, LABIDURIDAE) TO HOT AND DRY CONDITIONS

We measured the degree of adaptation to a xeric environment of immatur es and adults of the striped earwig, Labidura riparia (Pallas). All st ages of the striped earwig were moderately tolerant to heat, with crit ical thermal maxima ranging from 45.2 to 46.1-degrees-C for small and large nymphs, respectively. Percentage body water content ranged from 58.9% for females to 75.6% for small nymphs. Cuticular permeabilities were similar for all stages and were within the range of those reporte d for xeric species, ranging from 8.5 mug water lost per cm2.h.mm Hg f or medium-sized nymphs to 17.0 mug water lost per cm2.h.mm Hg for fema les. Percentage total body water lost increased linearly with desiccat ion time. Lethal body water loss varied among stages and ranged from 4 7.6 to 52.9% for small and medium nymphs. The mean hour of death range d from 16.8 h for small nymphs to 70.7 h for large nymphs, indicating that small nymphs were the least tolerant of desiccating conditions.