In the infected cultures treated with 25 mg L− 1 DOC, mortalities were high, and were not significantly different from the infected cultures that were not treated. In contrast, in the infected cultures treated with 4 g L− 1 sea salt, mortalities were arrested, with 76% of the M. macrocopa alive at day 10 ( Table 1). Although survival in this treatment was significantly higher than in the infected cultures treated with humic substances [25 mg L− 1 DOC] (p < 0.01), it was significantly lower than in the uninfected controls (p < 0.05).