Insect identification and scouting
Insect pests are almost a year-round problem in Alabama. Pests can be above ground or below-ground. While it is somewhat easier to observe foliar insects, it is a daunting task to really know what is inside the soil before it is too late. Various soil insects such as wireworms, cutworms and white grubs among many others are regular occurrence in commercial and home vegetable gardens. It is always very important to take a shovel sample of soil in raised beds or open field to retrieve sample of insect pests that may be infesting the soil. Always use the camera on your smart phones to take pictures and share them with your Extension Agent for proper identification.
Measuring Soil Pests
The following are some common measures to measure soil pests:
- Grassy areas turned into vegetable production areas typically seem to suffer from soil insects since grasses provide an ideal habitat for many as early season host plants. Occasional soil tillage early in the spring and in fall can be effective in disrupting the life stages of soil insects and expose them to natural enemies.
- Carefully plan your crop rotation as repeated planting of same crops can encourage buildup of soil pests that can be very difficult to control. Interplanting with diverse families of plants can confuse pests and encourage natural enemies to some extent.
- Control weeds carefully in and around your vegetable production area as pests like to hide or breed in unmanaged vegetation.
- When using soil granular insecticide, remember to put it in furrow or mixed with the top several inches of soil, so that pests may contact the active ingredient. Soil insecticides may also need moisture for activation – simply dropping a high concentration of granules on the top soil may not be effective for immature insects living near the root zone of plants.
- Do not cut the application rate of soil granular insecticides below the minimum as that will be ineffective the insect and may promote insecticide resistance. Follow the IPM Guide in your state and develop a site-specific IPM plan for your garden or farm.
- During drought, reduce insecticide usage overall to avoid flaring up spider mites and other pests. Remember to irrigate frequently and reduce any plant stress under dry conditions.
- Example of granular insecticides (organic/conventional): Bug-N-Sluggo (iron phosphate and spinosad), Monterey Ant Control and Fertilome Come-and-get-it (spinosad), Sevin Granule (zeta-cypermethrin), Hi-Yield or Ortho Garden Insect Killer (bifenthrin).
- If you are in Alabama, don’t forget to sign up for the Alabama IPM Communicator e-newsletter as the production season begins to stay informed of pest occurrences statewide. Visit https://www.aces.edu/blog/topics/ipm-farming/alabama-ipm-communicator-newsletter/ and complete the online form to join the email list.