Trap Cropping
This IPM method lures pests away from your garden.
Trap cropping is an alternative form of pest management that uses biological control to shepherd invading insects away from your main crop. This method of distraction helps reduce pesticide use and limits damage from insects when used in tandem with other integrated pest management (IPM) techniques.
What is a trap crop?
A trap crop can be defined as a sacrificial plant that draws away damaging insects from the “main crop,” or your desired species. This method of pest management involves planting species that the invading insects would choose over the main crop if given the choice. The goal is to eradicate the pests that collect on the trap crop before they move on to the main crop.
Trap crops can attract pests in different ways—some release scents or visual cues that draw in target insects, while others serve as “dead-end” traps, where pests lay eggs but their larvae don’t survive. Some trap crops can help bring in beneficial insects that naturally manage pests, while others serve as an attractive food source.
When and how to plant
Insects are particularly attracted to plants that mature quickly or are in the reproductive stage of growth. Trap plants are most attractive when they produce some type of seed, fruit, or flower. It’s recommended to plant trap crops before the main crop; pests are attracted to the plant that matures first. Exact timing of the planting can vary depending on the pest species being managed. In some cases, planting trap crops 3-4 weeks prior may be necessary for them to be fully effective.
Your trap-cropping design will also vary depending on how the target pests attack. “Perimeter trap cropping” creates a defense border, like fortress walls, to stop the pests before they reach the main crop. Perimeter trap crops should be planted at least 5 feet away from the main crop to prevent easy access to your desired plant. This style is best suited for pests with limited mobility. Planting intermittently by scattering trap crops throughout the main patch works best for insects that can move between plants quite freely. The number of trap plants used should be roughly 10 to 20% of the main crops.
What to plant
Some research has demonstrated that certain trap crops can attract specific pest species, so it’s important to identify which insects needs to be targeted. For example, collard greens have been used as a trap crop to attract diamondback moths away from cabbage. Blue Hubbard squash is useful in luring cucumber beetles, squash bugs, and squash vine borers away from cucurbit crops (i.e. zucchini, summer squash, or cucumbers). Sunflower and grains such as triticale, sorghum, millet, and buckwheat can serve as a trap for stink bugs. Sorghum and sunflowers can also be used as a trap crop for leaffooted bugs, luring them away from tomato plants. Mustard has been an effective control of harlequin bugs on collards.
How to manage
It is important to scout for pests multiple times a week to determine which species are present and how many are infesting the plants. This will help you address the issue as it surfaces and prevent the pests from getting out of hand. Once the damaging insects have established themselves on your trap plants, you must eradicate them to prevent them from moving on to the main crop. You can remove insects manually from the trap crop or use insecticides. If insecticides are used in a timely manner, the main crop likely won’t need to be sprayed. This means that your overall insecticide use is reduced when compared to treating the whole garden.
Trap cropping is an excellent way to manage damaging insects but it’s not the complete solution. Using trap crops as part of integrated pest management (IPM) will give your efforts a more holistic approach. The goal of IPM is to take preventative measures to manage pests and decrease the use of pesticides, which sends less chemicals into the environment and prevents pesticide resistance.
Other IPM intervention methods that could be used alongside trap cropping include crop rotation and planting “right for the site.” Minimizing drought stress and other challenges will also increase pest resistance and lead to more success.
Overall, trap crops offer an alternative solution for pest control by distracting insects away from your desired crop. This method, when initiated in tandem with other IPM techniques, can help diversify your landscape and allow for your desired crops to be healthy and productive. Trap cropping does require some planning and knowledge of pest species, so we recommend referring to the links below and contacting your county UF/IFAS Extension agent for assistance.
Also on Gardening Solutions
More from UF/IFAS
- Intercropping, Crop Diversity and Pest Management–Ask IFAS
- Trap Crops Help Combat Pests in the Garden–UF/IFAS Blogs Leon County