brunneum to kill half of the larvae; in addition M. brunneum appeared to kill faster at the highest concentration. An isolate of M. brunneum of similar origin as the one used here was also found by Bruck et al. (2005) to infect D. radicum, indicating the isolate’s potential in biological control against this pest. However, the important natural enemy of D. radicum, the parasitoid T. rapae, was also susceptible to infections by the tested fungal isolates. The current study demonstrated that T. rapae can experience foraging time constraints at different fungal concentrations, particularly when exposed to M. brunneum.

This study thus highlights that there is a risk associated with host foraging in fungal contaminated host

patches for T. rapae. Jones (1986) observed that the first 6 days after emergence Transmembrane Transporters activator is the most fecund period for T. rapae. In the current study the median survival time for this proovigenic wasp at the lower fungal concentrations tested was greater than 6 days. If a T. rapae female becomes infected, while emerging from soil contaminated with high levels of fungal inoculum, its fitness (i.e. reproductive success) is severely reduced if death occurs within the first 6 days. However, if the female has sufficient time to oviposit in high quality hosts before it dies, its fitness may not be significantly affected by the fungal inoculum. Applying a minimum dose required for adequate biological control of D. radicum in Selleckchem BIBF 1120 cruciferous crops will likely reduce the infection risk on T. rapae and allow the parasitoid population to persist. In a field situation the ecological susceptibility ( Roy and Pell, 2000) would probably be different due

to e.g. abiotic factors and local habitat differences. Surviving a fungal infection may have fitness Parvulin consequences (i.e. reduced lifetime fecundity). This needs to be investigated for T. rapae (e.g. Alix et al., 2001), since sublethal effects of entomopathogenic fungi on reproduction have been observed for other insects ( Baverstock et al., 2006, Roy et al., 2008 and Seiedy et al., 2012). Since both of the fungi tested are pathogenic to T. rapae it would be beneficial to the foraging parasitoid to evaluate the risk of infection in the host patch environment to reduce or avoid interaction with the fungus. However, no behavioral responses towards IGP risk posed to adult T. rapae were observed when either M. brunneum or B. bassiana were present in the choice situation. This inability to avoid either of the two fungi was counterintuitive since an IGP threat exists. Free conidia in arenas simulating natural habitats of other insects, including natural enemies, have been found to be deterrents. For example, termites were found to avoid the odours from dry conidia in sawdust, and the magnitude of response was related to the virulence of the fungal isolate ( Mburu et al., 2009). Meyling and Pell (2006) found that a predatory bug avoided B.