Previous laboratory studies have indicated that tenebrionid beetles infected with Hymenolepis diminuta display behavioural
alterations. These are assumed to increase the likelihood of this intermediate host being predated by the Rattus sp.
definitive host, and hence provide support for the Manipulation Hypothesis. We tested this hypothesis by both assessing
beetle behaviour and predation rates in semi-naturalistic environments. Behavioural assays showed that infected beetles
were more often exposed (not concealed under boxes) than uninfected beetles. However, there were no differences in
predation rates between infected and uninfected beetles. We discuss this in terms of the historical and evolutionary contexts
under which such altered behaviours could evolve and their implications for the Manipulation Hypothesis.