The results of many recent pest management studies, which demonstrate the positive impacts of plant diversification on populations of beneficial insects in agricultural systems, are included in the table below. Use this table to determine the intercrops and related management mechanisms that will mitigate specific pests plaguing your crops. See Key References for literature reviews and additional citations to these studies.

Apple Phacelia sp., Eryngium sp. San Jose scale, aphid Parasitic wasps
Weedy ground cover Tent caterpillar, codling moth Parasitic wasps
Barley Alfalfa, red clover Aphid Predators
Bean Goosegrass, red sprangletop Leafhopper Chemical repellent
Brassicas Candytuft, shepherd’s purse, wormseed mustard Flea beetle Chemical repellent
Similar-sized crops Rootfly, cabbage butterfly and moth Chemical repellent, predators
Brussels sprouts Weedy ground cover Imported cabbage butterfly Predators
French beans, grasses Aphid Physical interference
White clover Cabbage root fly, aphid, white cabbage butterfly Visual masking
Clover Aphid Physical interference
Cabbage Tomato Diamondback moth Uncertain
Hawthorn Diamondback moth Attract pest to alternative plant
Red and white clover Cabbage aphid, imported cabbage butterfly Physical interference, predators
Clover Cabbage root fly Predators
Green ground cover Imported cabbage butterfly Visual masking
Carrots Onion Carrot fly Chemical repellent
Cauliflower Corn spurry Cabbage looper, flea beetle, aphid Predators
Lambsquarters Imported cabbage butterfly Predators
White or red clover Cabbage aphid, imported cabbage butterfly Physical interference, predators
Collards Tomato, ragweed Flea beetle Chemical repellent
Pigweed, lambsquarters Green peach aphid Predators
Weedy ground cover Cabbage aphid Parasitic wasps
Weedy ground cover with wild mustards Flea beetle Predators
Tomato, tobacco Flea beetle Chemical repellent
Weedy ground cover Flea beetle, cabbage butterfly Uncertain
Weedy ground cover Flea beetle Visual masking
Corn Wild parsnip, wild mustard, chickweed, shepherd’s purse, and lady’s thumb smartweed Black cutworm Parasitic wasps
Pigweed Fall armyworm Uncertain
Giant ragweed European corn borer Parasitic wasps
Sweet potato Leaf beetle Attract pest to alternative plant
Beans Leafhoppers, leaf beetle, fall armyworm Physical interference, Predators
Beans, weeds Fall armyworm Predators
Pigweed, Mexican tea, goldenrod, beggertick Fall armyworm Predators
Soybean Corn earworm Predators
Peanut Corn borer Visual masking
Clover Corn borer Physical interference
Cow pea Sorghum Leaf beatle Chemical repellent
Cucumber Corn, broccoli Striped cucumber beetle Physical interference
Crucifers Wild mustard Cabbageworm Parasitic wasps
Fruit trees Rye, wheat, sorghum used as mulch European red mite Predators
Alder, bramble Red spider mite Predators
Grapes Wild blackberry Grape leafhopper Parasitic wasps
Johnsongrass Pacific mite Predators
Sudangrass, johnsongrass Willamette mite Predators
Kale, closely planted Aphid Visual masking
Kale Weedy ground cover Beanfly Physical interference
Mung beans New Zealand white clover Fruit fly Physical interference
Oats Carrots Thrips Visual masking
Onions Ragweed Oriental fruit moth Parasitic wasps
Peach Strawberry Oriental fruit moth Predators
Ragweed, smartweed, lambsquarters, goldenrod Oriental fruit moth Uncertain
Radish Broccoli Green peach aphid Parasitic wasps
Soybean Corn, weed cover Corn earworm Parasitic wasps
Sicklepod Velvet bean caterpillar, green stink bug Uncertain
Desmodium sp., Croton sp., Cassia sp. Corn earworm Parasitic wasps
Barley, wheat Monitored only predators of soybean pests Predators
Rye Seedcorn maggot Physical interference
Squash Corn Cucumber beetle Physical interference
Corn, cow pea Western flower thrips Predators
Sugar beet Manure Pests preyed upon by predatory ground beetles Predators
Broccoli Green peach aphid Parasitic wasps
Sweet potato Morning glory Argus tortoise beetle Parasitic wasps
Tamarack trees White spruce and shrubs Sawfly Chemical repellent
Tomato Cabbage Flea beetle Chemical repellent
Cabbage Diamondback moth Chemical repellent
Turnip Dutch white clover Cabbage root maggot Chemical repellent
Vegetables Wild carrot Japanese beetle Parasitic wasps
Walnut Weedy ground cover Walnut aphid Parasitic wasps