Using Trap Crops to Minimize Damage by Insect Pests to Veggies

Published: May 1, 2011

The Integrated Pest Management Program at Lincoln University of Missouri is seeking out for affordable alternative insect pest management strategies to combat the growing threats to the smallholder’s livelihoods in Missouri. One such method is called trap cropping.

What are trap crops? Trap crops are plants that are planted next to a higher value crop so as to attract pest as either a food source or oviposition site, thus preventing or making less likely the arrival of the pest to the main crop (= cash crop). Insects congregated in trap crops can be more easily attacked by natural enemies and/or killed by insecticides or by other physical means. In other words, trap cropping functions by concentrating and/or killing the pest in the border area, while reducing pest numbers on the unsprayed cash crop. Plant species or cultivar used needs to be more attractive to pest than crop is.

Advantages: By using trap crops farmers can: (1) lessen pesticide use and decrease costs, (2) preserve indigenous natural enemies, (3) improve crop’s quality, and (4) help conserve the soil and environment.

Tips for successful trap cropping: (1) learn to know and identify the pests and their natural enemies, (2) make a farm plan to guide you on where and when the trap crops will be planted, (3) monitor your plants regularly, (4) immediately control the pests that are found in your trap crop, otherwise they will serve as a breeding ground, (5) if needed, be ready to sacrifice your trap crop as an early crop and destroy them as soon as the pest infestation gets too high, and (6) Always keep farm records. What trap crops worked best and against which insect pests?

Blue Hubbard has worked well as a trap crop for cucumber beetles

Examples: (1) In Massachusetts, 6 butternut growers planted a Blue Hubbard border around butternut squash fields that ranged in size from 2 to 6 acres. These 6 fields were compared to conventional butternut fields where beetles were controlled with fullfield insecticide sprays. Fields were scouted twice weekly until first leaves, then weekly until flowering. Borders were sprayed at the first arrival of the beetles. Cucumber beetles were only found in the trap crop and insecticides were only applied to the perimeter trap crop. As a result, 85% less insecticide was used. (2) In Missouri, a farmer in St. Peters was able to prevent cucumber beetles from eating his indoor cucumber transplants by using Blue Hubbard planted in pots and placed outside of his high tunnel. Four potted plants congregated hundreds of beetles while none was found inside the high tunnel. Research led by Dr. Pinero is being conducted in this area for the benefit of Missouri vegetable farmers. Other examples of specific trap crops are presented in the Table below: