Exploring the world of problematic plant pests, beneficial bugs and how to best avoid and treat infestations, here we have two helpful creatures for outdoor gardens. One is a parasite — the Trichogramma wasp — that kills caterpillars. The other — the praying mantis — is a carnivorous beast that will eat aphids and more.

Both biological controls are most likely to be used outdoors, but are found in the indoor gardening world usually  in a green house or grow room.

Caterpillar Killers: Caterpillars can wreak havoc on your plants, which is more problematic for outdoor gardeners. They feast on leaves and foliage and generally just screw with crops. Cute, yet a major nuisance these creatures are.

One of their greatest enemies – the Trichogramma wasp, aka the “stingless wasp” – is a natural parasite that can kill more than 200 types of caterpillars. These tiny “good” bugs can look like gnats and don’t sting, but kill caterpillars before they’ve fully formed and hatched. In essence, the wasps lay their own eggs inside the moth eggs and the larvae “parasitize” (kill) what would have become caterpillars. The newly born Trichogramma wasp lives on to repeat the egg-killing cycle.

During its lifespan from development through its adult life (16-20 days total), female wasps can kill nearly 100 pest eggs.

Praying Mantis Eggs: These beautiful, carnivorous insects have hearty appetites and eat nearly any bug they can find. Their eggs are sold as biological pest controls, and as adults, are definitely an outside gardener’s friend.

When hunting for food, the praying mantis has remarkable, even admirable patience. It will wait for hours at a time for an insect to wander by, and when the moment is right, attack and kill it. They start out feeding on small insects like aphids and eventually mature to eating bigger, badder prey.

Praying mantis egg cases typically contain between 100 and 200 tiny mantises, which hatch at one period in time. The cases should be attached to a twig or the underside of a leaf; they need several weeks of consistently warm weather to hatch, so be patient.

But be careful because these green creatures will eat anything they can, including your little lady bugs. They have no qualms about eating beneficial bugs as well as the pests you are looking to eradicate.