WARNING: This compound has not had a chance to become canonical.
Na͡ichormysa is a chemical compound distributed to their intended kavkem recipients through carrier mammals, much like Serrata. It reduces kavkem fertility sharply when ingested, but otherwise has few negative effects. Most kavkema are not aware it exists, but given reluctance to eat mammals in areas where Serrata is common, Na͡ichormysa also has little chance for wide-spread effect.
Only rarely can Nayabaru deploy only Na͡ichormysa into a kavkem population that is not wary of Serrata, but it has been done successfully in the past. Since those kavkem populations consequently disappeared, Na͡ichormysa is now mostly of historic interest to the Nayabaru - it still works fine, but the delivery mechanism is too tarnished.