Terumot, Chapter Ten, Mishnah Nine
Leviticus 11:22 states that some locusts can be eaten, but according to the rabbis there are other types of locusts that may not be eaten. In the time of the Mishnah they knew how to tell the difference between the kosher and the non-kosher locusts, but most Jews today do not eat locusts. Perhaps this is cultural bias, but I dont really feel like Im missing out.
1) If unclean locusts were pickled together with clean ones, they do not make the brine forbidden.
2) Rabbi Zadok testified that the brine of unclean locusts is clean.
Section one: The locusts will not pick up the taste of the other locusts that they are pickled with. Therefore, the clean ones remain permitted. However, according to this opinion, the brine itself is prohibited because it does pick up the taste of the unclean locusts.
Section two: According to Rabbi Zadok even the brine is permitted.