Proportion infected larvae from all five experiments (total number infected after 14 days). Data presented as a mean for groups fed the lower dose P. larvae (group 1); groups fed the lower dose P. larvae and LAB (groups 2 and 3); groups fed the higher dose P. larvae (group 4); groups fed the higher dose P. larvae and LAB (groups 5 and 6). The difference between groups fed the higher dose of P. larvae was significant (P = 0.005). The mortality in the uninfected control group was less than 17% in all experiments.