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fire ant damage in hemp

Fire ants have been identified causing severe damage in hemp plants. They are chewing on the plants at the base and even tunneling into the stem. In some cases, the fire ants will chew further up the stem of the plant. In most instances, the chewing damage girdles the plant and the plant dies. Widespread damage has been seen in plants grown in open fields, pots, and on plastic. Dr. Katelyn Kesheimer, Extension entomologist, in conjunction with the Alabama Department of Agriculture & Industries (ADAI), has identified some pesticides that can legally be applied to hemp. Below is a list of products approved for fire ant control in hemp grown in Alabama.  Figure 1 (seen above) shows wilting and collapse of hemp plants caused by fire ant feeding at the base of plant.

Fire ant damage in hemp

Fig 2. Chewing and tunneling damage on hemp caused by fire ants.

fire ant damage in hemp

Fig 3. Extensive chewing and tunneling damage on hemp caused by fire ants.

Approved Insecticides Labeled for Fire Ants

Brand NameEPA Registration NumberPesticide TypeActive Ingredient
Bonide DE Crawling Insect Killer 73729-1-4InsecticideDiatomaceous Earth
Botanigard Maxx82074-5InsecticidePyrethrins, Beauveria bassiana Strain GHA
Extinguish Professional2724-475InsecticideMethoprene
Ferti-Lome Triple Action Plus Insecticide Fungicide Miticide70051-74-7401Insecticide, Miticide, FungicidePyrethrins, Clarified Hydrophobic Extract of Neem oil
Fruit Tree Spray Plus 70051-111-54705Insecticide, Miticide, FungicidePyrethrins, Clarified Hydrophobic Extract of Neem oil
Pyronyl Crop Spray89459-26InsecticidePyrethrins, Piperonyl Butoxide
Shield-All Plus 70051-111-56872Insecticide, Miticide, FungicidePyrethrins, Clarified Hydrophobic Extract of Neem oil
Orange Guard061887-CA-001Insecticided-Limonene

Approved Insecticides Not Labeled for Fire Ants with Broad Insect Control

Brand NameEPA Registration NumberPesticide TypeActive Ingredient
Azatin O70051-9-59807InsecticideAzadirachtin
Azera Pro1021-1872InsecticidePyrethrins, Azadirachtin
Bug Buster-O1021-1771-54705InsecticidePyrethrins
Celite 61073729-1InsecticideDiatomaceous Earth
Deadzone73729-1InsecticideDiatomaceous Earth
Ferti-Lome Horticultural Oil Spray48813-1-7401Insecticide, Miticide, FungicideMineral Oil
Ferti-Lome Horticultural Oil Spray Ready to Spray48813-1-7401Insecticide, Miticide, FungicideMineral Oil
Lynx EC 1.482074-6InsecticidePyrethrins
Lynx EC 5.082074-7InsecticidePyrethrins
M-Pede*
*M-Pede has many label restrictions regarding usage and tank mixes. Read label carefully.
62719-515Insecticide, FungicidePotassium Salts of Fatty Acids
Ortho Tree and Shrub Fruit Tree Spray Concentrate70051-75-239Insecticide, Miticide, FungicidePyrethrins, Clarified Hydrophobic Extract of Neem oil, Piperonyl Butoxide
Pyganic1021-1772InsecticidePyrethrins
Pyrethrum TR Total Release Insecticide499-479InsecticidePyrethrins, Piperonyl Butoxide

These are all broadly labeled tolerance exempt pesticides. Other pesticides may be used but must be approved by ADAI. For approval, contact a member of the Extension Hemp Action Team (see list below). The team will forward the request to the correct ADAI contact.

When choosing pesticides for use on hemp, consider the following.

  • The active ingredient must be exempt from the requirements of a tolerance on all food crops.
  • The label must have directions for use on unspecified food crops.
  • The pesticide must be registered by the EPA or exempted from registration.
  • The pesticide must be registered by ADAI.
  • The label must be sufficiently broad to include hemp and not prohibit its use on hemp.

While the products listed are legal to use in Alabama, it is important to note that most processing companies will test for pesticide residues and that each pesticide has a residue limit. If the tested hemp exceeds that pesticide limit, your hemp will fail the processing company’s standards.

fire ant damage in hemp

Fig 4. Chewing damage on hemp at base of plant and further up the stem caused by fire ants.

fire ant damage in hemp

Fig 5. Yellowing and wilting symptoms on hemp caused by fire ants feeding on the base of the plant.

Before Applying Any Chemical

It is important that growers speak with their processing company to ensure their crop will be compliant. 

Hemp is susceptible to many insect pests and plant diseases. As Alabama Extension identifies problems that occur on hemp in Alabama, it will work with ADAI to compile lists of pesticides that can legally be applied to help control current problems. However, growers should remember that pesticides should only be used as a last resort.

We do not currently know enough about growing hemp in Alabama to be certain which insects will actually cause economic damage. The use of pesticides in hemp may lead to a lower oil content. Also, keep in mind that many pesticides can be phytotoxic. It is a good idea to apply the pesticide to a small group of plants and observe them for a few days before using on an entire crop.

Extension Hemp Action Team

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