The effect of Cry6Aa2 toxin on egg hatch of M. hapla was deter- mined by transferring 10 surface-sterilized egg masses to a single well of 48-well microtiter plate, including 20 lL Cry6Aa2 toxin with serial gradient concentrations or HEPES buffer (pH8.0) as con- trol, and 180 lL sterile water.