Organic Farming 101: Pest Control

The Damsel Fly (along with other beneficials) helps organic farmers by feeding on crop-damaging insects.

Pest control often makes or breaks an organic farmer’s year. Because we use fewer, less-toxic pesticides than those used by conventional farmers, we must rely on a variety of other methods to keep pests in check.

Beneficial Insects are Key to Our Success

At Earthbound Farm, our primary strategy for fighting harmful pests is to build up populations of beneficial insects that help us by eating adult pests, eating pest eggs, or by becoming parasites inside pest insects themselves.

These are some of the beneficial insects we use, and the pests they prey on (see an ID chart of our beneficial insect friends here):

Beneficial Insect
Preys On >
Pest Insects
Lacewing larvae > Aphids, insect eggs, leafhoppers, mealybugs,
mites, psyllids, small caterpillars, thrips,
and whiteflies
Ladybugs >
(both adults and larvae)   
Aphids, insect eggs, soft-bodied insects,
and whiteflies
Minute Pirate Bug >
Aphids, mites, psyllids, small caterpillars,
thrips, and whiteflies
Big-Eyed Bug >
Flea beetles, mites, small caterpillars, thrips,
worm eggs, and other pests
Damselfly >
Flea beetles, leafhoppers, mites, small
caterpillars, thrips, worm eggs, and other pests
Assassin Bug >
Aphids, caterpillars, leafhoppers,
and other pests
Syrphid Fly >
Aphids and soft-bodied insects
Parasitic Wasps >
Preys on a variety of pests; larvae feed on or
inside the bodies of pest insects, killing them

Host Crops as Habitats for Beneficial Insects

We build populations of beneficial insects by planting borders around our fields with “host crops,” flowering plants that the beneficials particularly like. We generally use plants such as buckwheat, alfalfa, clover, radish, yarrow, coriander, dill, carrot, vetch, baby’s breath, California poppy, bachelor buttons, and alyssum. We plant them once at every site, and they re-seed themselves every year.

The host crops are good habitat for the beneficial insects we periodically release into our fields, and they also attract more beneficials over time. The borders serve another extremely important function as “trap crops,” distracting pests from our crops by providing them with an alternative food supply. 

Crop Rotation Breaks the Infestation Cycle  

Organic farmers rotate crops for many reasons, and pest control is one of them. Insects are creatures of habit; if a food supply keeps coming back at the same place and same time each year, you can bet that insects will return, too. Thoughtful crop rotation disrupts this cycle. We try to anticipate where and when different pests will threaten our crops; then, as much as possible, we strategically adjust our planting schedules to avoid the likelihood of a serious infestation.

Insecticides Approved for Use on Organic Crops

When a pest outbreak can’t be handled by beneficial insects, we sometimes use insecticides approved for organic farming (meaning that they’re listed in the USDA’s stringent National Organic Standards). Criteria for allowed organic insecticides include low toxicity to people and other animals, low persistence in the environment, and low toxicity to beneficial microorganisms in the soil.

Sometimes the Insects Win

Although all farmers can lose a crop to pests, organic farmers are more vulnerable. Sometimes natural pest control strategies are very effective — but other times, nothing we do seems to work. Periodically we lose a large portion or all of a crop to pests, and everything must be tilled under. Occasional losses such as these contribute to the higher cost of organic produce.