Do you know how to treat the bug that is only appearing on eggplants?
Thank you for contacting Toronto Master Gardeners.
There are a large selection of insects/pests that attack Eggplants. Before one can begin planning a strategy to battle the insect it is important to have a positive ID on the insect attacking the plant. The method of combating the pest will be different for each pest and the wrong methods will have no effect.
If you look at the leaves on top or on the undersides or stem and soil you maybe able to find the culprit. Once you have that you can make a plan. Some bugs come out at different times of day so it may take some work to catch them in the act.
I am attaching two sites below to help you with identifying the culprit. Once you have that you can re-contact us or go to your local nursery for advice. Good Luck!
https://extension.umd.edu/learn/insect-pest-management-eggplant
https://growingsmallfarms.ces.ncsu.edu/growingsmallfarms-eggplant-diversity/