Praying Mantis

Your yard is crawling with insects—but not everything that buzzes, creeps, or wriggles is there to decimate your begonias. For every aphid ready to nosh on your flowers, there are predator bugs ready to feast on the nibblers themselves. Other insects serve as pollinators. Even the lowly earthworm enriches and aerates soil. So nix nuking the bad bugs with chemicals and encourage these good garden bugs to take up residence in your yard.
Named for the “praying” position its long and lanky front legs assume, this voracious, sticklike insect will eat just about any living thing it can fit in its mouth, helpful or not. It is known to consume mosquitoes, nocturnal moths, bees, beetles, small lizards, even frogs—as well as fellow praying mantises.
Ground Beetle

These shiny black beetles crawl out at night from under logs, stones, and boards to nosh on slugs, snails, cutworms, and root maggots. Your hostas, for one, will welcome their presence in shady beds and borders.
Green Lacewing

With two pairs of netlike translucent wings, this delicate-looking predator controls populations of soft-bodied garden pests, including many of the aphids, thrips, red mites, small caterpillars, and mealybugs that like to feed on the succulent foliage in your landscape. Adults round out their diet with nectar collected from flowers such as angelica and sweet alyssum.
Spined Soldier Bug

Also known as a “stink bug” for the foul odor it emits when disturbed, this shield-shaped beetle will save your vegetable garden from ruin as it seeks and destroys Mexican bean beetles, Colorado potato beetles, hornworms, cabbage loopers, and cabbage worms.
Ladybug

Imported more than 100 years ago to defend orchards and orange groves, these black-spotted red or orange beetles have yet to lose their appetite for soft-bodied, sap-sucking aphids, mites, and mealybugs. These good garden bugs can eat up to 5,000 pests in a lifetime, doing most of their feeding while in the larval stage, as tiny alligator-shaped, orange-spotted black grubs that also go by the nickname “aphid wolves.”
Braconid Wasp

Their stingers may scare off humans, but this parasite is more interested in feasting on caterpillars and sawfly larvae than on people. Flitting among the ‘Big Boy’ and ‘Brandywine’ tomatoes, they’ll keep the horn-worms in check.
Bumblebee

Easily identifiable by its fuzzy black and yellow stripes, this social creature makes its way from dandelion to rhododendron blossom, foxglove to rosebush, collecting nectar and the pollen that will make tomato plants and apple trees produce more fruit. Worker bees (females) can sting, but they much prefer to stick to gentler business.
Beneficial Nematode

These microscopic parasites live in the soil, where they seek out a wide variety of hosts, inevitably killing them. Turf-chomping white grubs and the larvae of dog-torturing fleas and rose-damaging Japanese beetles are all susceptible to beneficial nematodes, which have no taste for helpful earthworms and ladybug larvae.
Tachinid Fly

These bristly brown, black, or gray flies resemble ordinary houseflies but prefer the outdoor life, where they can consume pests such as tent caterpillars, gypsy moth larvae, and cutworms.
Earthworm

These burrowing brown scavengers are nature’s most efficient composters. You won’t find them in very clay or sandy soils, but enrich it with compost and top it with mulch to keep it moist, and they will come. Then they’ll proceed to create the kind of well-aerated, humus-rich soil gardeners call “black gold.”