Had the same problem... couldn't see what the bugs were (couldn't click on the garden at all) so I couldn't describe the bugs to the store clerk, and didn't know which bug spray to buy. Fortunately, I remembered some stuff from an earlier version, and it seemed to work.
Go to the store, tell the clerk the bugs have pincers on their backs. She'll recommend green capped bug spray. Take it to the garden (think I had to wait until the next day), play the garden mini game like normal, although the veggies all look rotten (Maybe remove EVERYTHING? Can't exactly recall.) When that's done, you should get the "you killed the bugs" resolution, and be able to move forward.
Anyway, that worked for me. Hope it works for you.