Japanese Beetle (Popillia japonica)
Detriment: Spawn from grubs and are a pest in all forms of their life cycle. They are voracious eaters of everything from grass roots to plant leaves and fruit.
Deterrent: Has a fondness for grass and lays its eggs in lawns midsummer. Use beneficial nematodes (microscopic soil-dwelling worms that can be purchased at many garden supply centers) to treat when certain there is a large population present. Floating row covers can help.
Lily Leaf Beetle (Lilioceris lilii)
Detriment: Colorful red insect that feasts on true lilies (Lilium spp.), not daylilies (Hemerocallis spp.)
Deterrent: Must hand pick adults and larvae. If they have burrowed into the bulb, crush them using the end of a coat hanger.
Detriment: Transfers diseases to both humans and animals.
Deterrent: Remove standing water from yard. Put netting over rain barrels.
Cabbageworm / White Cabbage Moth (Pieris rapae)
Detriment: A pest of a wide variety of plants, particularly species of Brassica oleracea (cabbage, cauliflower, broccoli, kale, etc.). Damage is usually cosmetic.
Deterrent: Parasitoid wasps are one of its chief enemies. Using a floating row cover can also help control it.
Detriment: Can damage plants roots due to its tunneling habit. Some species protect aphids from enemies and carry them to new plants. More of a nuisance inside the home than in the garden.
Deterrent: Sprinkle corn meal, which ants cannot digest, around the hills. Alternatively, pour a few gallons of boiling water on hills.