S. olivacea has setae number of 4,4 combination on both sides of the basal segment of antenna.It is different from three other species which are either 3,3 or 3,4 or 4,3 combination.

• 红脚蟳大眼幼体在左右第一触角基节的刚毛数均为4,4的组合，与其他三种的3,3，3,4或4,3的组合明显不同。