Parasites may have subtle effects in the distributions of their hosts, including altering thermal preferences. The immature stage of a heat-sensitive acanthocephalan thorny-headed worm inhabits several cockroach hosts before reaching maturity in the rat when eaten. Insects such as the cockroaches can induce fever behaviorally by choosing warm microhabitats. The study will assess whether infected and uninfected cockroaches respond differently to a temperature gradient, how cockroach temperature choice affects parasite level and whether temperature influences the effects of infection on cockroach reproduction and longevity. By using several cockroach species this study examines the effects of diverse cockroach attributes on expression of fever. This is the first study to 1) examine fever in a worm-insect association, and to assess its effects on survival and reproduction of several host 2) test the alternate hypothesis that altered behavior in parasitized animals may benefit the host (fever) as well as the parasite (increased transmission to predators) and 3) place insect febrile responses in a comparative, phylogenetic context. The study species are important elements of urban ecological systems .
