Just a quick comment on pest control ( and the key word here is CONTROL). It's a fact of life that the bugs will show up, but keep in mind that there are GOOD bugs too. I do think killing the plant is a little harsh... and temporary. May as well live in a sterile environment with plastic flowers.
The best way of dealing with the pests is to try to control the amount
of infestation, and not poison everything else in the process. Hand picking/crushing works in the beginning. Where aphids are concerned, the next step would be a good, strong blast with the hose and literally blow 'em off the plant. Meanwhile, Nature may step in and give you Lacewings and Ladybugs with their voracious appetites for aphids. Lastly,
, there is Rotenone (a plant-based pesticide that will kill most anything, but breaks downs quickly in the environment).
Tomato hornworms can do a lot of damage, but can be hand picked as soon as you learn how to spot them in all that greenery... BUT... if you see little white 'grains of rice' hanging on one, leave it alone. That's eggs a tiny wasp laid on the caterpillar, and the critter will die very soon.
I usually have on hand a coffee can half full of water, and a 1/2" layer of motor oil on top. I just drop or knock the bugs in and that's the end of them.
Colorado Potato Beetles just love eggplant. They start out as little yellow egg clusters under the leaves, then hatch into slimey-looking red blobs.. these will grow a bit, then at some point become the beetle that has a yellow body with black stripes lengthwise. Try to get the beetles as soon as you spot them before they can lay too many eggs.
Of special note... Ladybug larve are the ugliest looking critters, and I nearly killed them before I found out they were the infantry come to help. I would suggest reading up on the common garden pests and friends
before going into an absolute panic.