A trap crop is a method of pest control where an attractive host plant is grown/planted to lure insects away from the main/desired crop. For example, blue hubbard squash is often planted beside or along the outside of an area of other squash or cucumber plants. Since cucumber beetles prefer blue hubbard over other types of squash, growers can check these plants for early signs of pests. In addition, if the pests are already more established, the hubbard squash plant(s) can be removed and destroyed, taking the cucumber beetles along with them.
Trap crops can be of the same species like the hubbard squash protecting other squash and cucumber plants, or of different species like nasturtiums (which aphids love) to protect brassicas (ex. broccoli). Trap crops can be used as a border crop to surround the main crop. They can also be planted earlier than the main crop such as early tomatoes grown to protect later season tomatoes.
Trap crops are used by farmers due to their ability to provide an early indicator of damaging pests and to reduce pesticide use due to the removal of the trap crop once infested. They have a low environmental impact, don’t require much additional labour to manage, and generally have a low cost of seeds.
Other examples of trap crops include hot cherry peppers to protect bell peppers and early tomatoes to protect later season tomatoes. Not all insects or crops are suitable for a trap cropping strategy, and its effectiveness is dependent on the skill of the farmer and knowledge of insect behaviour.
Cover Image by F Delventhal, used under its Creative Commons license.