Q.How do I rid my cassia tree of sulphur butterflies?
My Cassia tree is recently new to my yard, about 8 ft tall. It has gotten caterpillars on it. I think they are from the sulphur butterfly. How do I rid my tree of these??
Here is a photo of a sulphur caterpillar: Is this what you have?
http://www.obsessionwithbutterflies.com/blog/2009/07/recipe-for-sunshine/
Cassia trees are a host for Sulphur Butterflies. The butterflies lay eggs on them which hatch into caterpillars that eat cassia foliage\blooms before they undergo the transformation into a butterfly. The caterpillars will probably not irrevocably harm your tree and will turn into beautiful butterflies that act as pollinators.
If you still want to pursue removal, you can pick them off your tree by hand, or the more drastic option, spray with biological insecticides such as Dipel or Thuricide.
For information on caterpillar remedies, please visit the following link:
https://www.gardeningknowhow.com/plant-problems/pests/insects/prevent-caterpillars.htm