I’ve got grubs in my vegetable garden. I looked into spraying nematodes to kill them, but I’m worried about it harming other bugs like butterflies, bees, and fireflies. Anyone have any experience with this? I don’t want to do more harm than good.
Nay. Good soil practices will balance your problems themselves. Allow proper soil maintenance to maintain your biome and you will have less problems with insects and disease. No till. Beneficial bacterias. Effective microorganisms. Home made made fertilizers, composts and teas (Korean natural.farming techniques).
Grow good soil with active ingredients and bugs and it will do the work for you.
If you can but it might be too soon if they are in next stage a safe one is Bacillus Thuringiensis. It kills caterpillars or any larvae with midguts.
Where does one acquire this magical bacterium?
Most garden centers carry it. I used Monterey B.t. spray for a really bad inchworm infestation. It worked really well, but it does stink.
https://en.wikipedia.org/wiki/Nematophagous_fungus
Nematophagous fungi are carnivorous fungi specialized in trapping and digesting nematodes. More than 700 species are known. Species exist that live inside the nematodes from the beginning and others that catch them, mostly with glue traps or in rings, some of which constrict on contact. Some species possess both types of traps.
you can introduce one of the fungi listed on that page and eat it too