CONICET | Buscador de Institutos y Recursos Humanos

En masse inoculations with Paranosema locustae, an intracellular parasite of adipose tissue of grasshoppers andlocusts and the only microsporidium registered as a biocontrol agent, were conducted against crowded fourthinstarnymphs of the South American locust Schistocerca cancellata and the grasshoppers Dichroplus schulzi and Ronderosia bergii. Infection did not develop in the locust, but was highly prevalent in the two grasshopper species.We hypothesize that absolute absence of infection in S. cancellata may constitute a case of density-dependentprophylactic resistance, an elevation of the baseline immunity of an organism in order to cope with diseasethat is prevalent in species exhibiting phase polyphenism.