Thanatosis or feigning death in mites of the family Scutacaridae

Abstract

First indications of thanatosis or feigning-death reaction in species of the terrestrial Scutacaridae were seen in the course of breeding experiments with different species of the genera Scutacarus, Pygmodispus and Lamnacarus. Seven of the 19 species studied reacted to foreign touch stimuli by retracting their legs and remaining immobile for a maximum of 6 min 20 s (Fig 38.1a, b). In all species in which larvae and males were also available, it was found that only females displayed this behaviour. The larvae and males, which differ from females in their morphological structure, moved away rapidly when touch stimuli were applied.