An experimental test of potential host range in the ant parasitoid Apocephalus paraponerae

1. The work reported here tested experimentally whether specialisation in Apocephalus paraponerae was due to physiological interactions that limit the parasitoid to the host ant Paraponera clavata. The suitability of other ant species as hosts was tested, and behavioural traits that may promote a high degree of specificity within this host–parasitoid system are discussed. 2. Data for development time, number of puparia, and adult eclosion success for A. paraponerae ovipositing in the regular host P. clavata are provided. A new method for testing host suitability in parasitoids of ants is described. Eggs of A. paraponerae were transferred directly into potential ant hosts. The development time, number of puparia, and adults eclosed for the eggs transferred into other ant host species are compared with comparable data from P. clavata. 3. Seven ant species within the Ponerinae are suitable for the development of A. paraponerae. The potential host range is greater than the actual host range of A. paraponerae. Flies are not limited solely by host suitability of related ant species for the development of larvae. Host location and acceptance behaviours are proposed as the primary reasons for host specialisation. The large size of the primary host P. clavata, and the ability of multiple females to raise many offspring successfully from those hosts may influence the specialisation of A. paraponerae on P. clavata.