Many different insects can be found in hemp fields, however, not all of them are pests. Within the complex of insects and mites found in hemp, we can find pests, predators, parasitoids, pollinators, and incidental arthropods.
Colorado State University has detailed fact sheets for many of the pests and natural enemies found in hemp. Some pests that could be a concern for hemp growers will vary depending on the type of hemp produced (fiber, grain, or cannabinoid), the growing environment (indoor or outdoor), and the geographical location of the field(s).
Indoor pests of concern include; cannabis aphid, rice root aphids, thrips, whiteflies, fungus gnats, hemp russet mite, broad mites, and spider mites. Hemp appears to be susceptible to typically greenhouse pests.
Outdoor pests of concern include; flea beetles, corn earworm, cutworms, cannabis aphid, hemp russet mite, spider mites, potato leafhopper, Eurasian hemp borer, and European corn borer. Some pests are abundant in the field, but the damage is minimal. Just because you see damage does not mean you should immediately spray a pesticide product. In Indiana, we have a list of allowable pesticides that can be found here (PDF). If you see pest damage in your hemp, take clear photos of the pest and the damage, and collect specimens so we can try to determine which pests you are finding in the field. Some pests may be really easy for you to identify, but the Purdue Plant and Pest Diagnostic Laboratory provides pest identification for a fee.
There are natural enemies of pests found in hemp fields, which provide natural pest suppression. When managing pests in hemp, you should also consider natural enemies and pollinators when selecting pesticides.
- Integrated Pest Management of Hemp in Virginia
- Insect and Mite Pests of Field Grown Hemp in Wisconsin