Trap Crops fit into the realm of companion planting.  Though the process may go against a traditional gardeners nature you must place your faith in The Bug Lady and understand the logic.

The concept is to plant a species of plant susceptible to a specific pest to act as a lure for beneficial insects, such as Lupines.  The Lupine aphid (macrosiphum albifrons) is specific to Lupines and will not transfer onto your peppers or cabbage.  The sacrificial plant is allowed to have a colony of aphids establish.  Once the host plant achieves a pest colony the parasitic wasps and predators will also move onto the Lupine as well. Voila, a pocket insectary.  The Lupine provides a source of predators without threatening the intentional crop. By situating the trap plants around gardens which typically suffer from aphids, you are actually protecting your gardens by providing an established security force.

It is important that when you attempt to apply this method using other plants as the trap crop that you confirm the pest species is host specific. Obtain this information through a reliable source.   A search through our links is a good place to start.

The Following list has been gathered from; Common Sense Pest Control by William and Helga Olkowski and Shiela Daar,  Rodales Encyclopedia of Organic Gardening, Cornell University and Appropriate Technology Transfer for Rural Areas.

Predator Host pests Associated Companion plants
Aphidoletes Aphids Dill, Mustard, Thyme, Sweet clover
Braconid Wasp Armyworm
Cabbageworm
Codling moth
Gypsy moth
Beetle Larvae
Flies
Nectar plants with small flowers.
Caraway, Parsley, Fennel, Mustard,
Clover, Tansy, Yarrow.
Damsel Bugs Aphid, Thrips
Leafhopper
Treehopper
Small caterpillars
Sunflower, Goldenrod, Yarrow, Alfalfa
Groundbeetles Slugs, snails
Cutworm,
Cabbage maggot
Some small caterpillars
Aamaranth, sweet clover, mulches,
groundcovers
Lacewing Aphids, Thrips,
Mealybug, Scale
Caterpillars, mites
Angelica, Caraway, Dill, Coreopsis
Cosmos, Sunflowers, Dandelion
Minute Pirate Bug
Thrips, Spidermite
Leafhopper,
 Earworm,
Small Caterpillars
Bishops weed, Chevril, Tansy,
Queen Annes Lace, Strawberries,
Carrots, Corn, Hairy Vetch, Daisies,
Nemophila, Coriander
Rove Beetles Aphids, flies, Springtails Rye, Ornamental grasses, mulches
Stethorus Spidermites Carrots, Dill, Fennel, Sweet
Alyssum, Candytuft
Syrphid Fly Aphids Dill, Fennel, Queen Annes Lace
Coriander, Bishops weed, Tansy
Lupines, Scabiosa, California
Lilac,Ceanothus, Sunflowers
Tachinid Fly Cutworms, Tent
Caterpillars, Cabbage
Looper, Sawfly,
Sowbugs
Caraway, Bishops weed, Goldenrod
Sweet Alyssum, Parsley, Buckwheat

 

Trap Crops for Aphids:
Lupine
Dill
Timothy Grass
Nasturums
Valerian

Trap crops for Thrips:
Shasta Daisy
Sunflowers

 

 

 

http://www.thebuglady.ca/planting.htm