HEllo, my name is Jessica and I have a serious issue with some kind of bug killing all of my hostas and my bleeding heart. I've noticed little flies in the soil (guessing fungus flies) and little worms around the base of a couple plants (larva?) most of the damage is at ground level, do you know what it could be? And how can I stop them?? I'm heartbroken over the loss of multiple of my favorite plants and I'm about to give up one of the most loved hobbies I have. Also, the yard has like pock marks in it where it just dips down everywhere about the size of a softball, could this be the doing of grubs or worms? Any advice would so very much appreciated. Thank you for taking the time to read this and I look forward to your response.
Jessica, hostas are favorites of slugs, flea beetles, aphids, and whiteflies. Of these potential pests, the most likely culprits are slugs. Slugs are nocturnal and usually hide beneath the soil or mulch during the day. In the evening and very early morning, they attack the plant and feed until the foliage is destroyed. I always recommend sprinkling a product called Sluggo around the plants to deter slugs. An organic product called Escar-Go is also available on-line through a company called Gardens Alive. It is extremely effective.
For the flying insects, I believe an insecticidal dust such as sevin or rotenone is your best option. Sprinkle it on the foliage on a day when you know it will be dry for at least 48 hours. The dust will kill any insects it comes into contact with and will remain on the plant for several days, or until you receive a heavy rain.
I hope this answered your question. Good luck, and please write again if I can ever provide assistance.