Pale-spotted Emperor

1. A black triangular spot at where the frons sticks to the compound eyes

2. Synthorax green with no apparent stripes at two sides

4. Spots on abdomen dot-like

 

Blue-spotted Emperor

1. “工”-shaped black spot on the frons

2. Synthorax green, two sides with apparent black stripes

4. Spots on abdomen dot-like

 

Lesser Emperor

1. Two black stripes on the frons

2. Synthorax green, without apparent stripes on two sides

4. Spots on abdomen strip-like