hemp pest management

Commercially cultivated hemp is skyrocketing in the U.S., thanks to the passage of the 2018 Farm Bill, which removed hemp from the list of controlled substances and legalized its growth. Hemp production can be broken down into three distinct categories: grain, fiber, and the compound cannabidiol (CBD) for consumer usage. Regardless of the hemp you are producing, one thing remains true: you need to manage and minimize the economic impact of hemp insect pests on your crop.

Since hemp has not been cultivated broadly in so long, the crop is considered new again, as is the research into what pests and insects may cause economic harm to the crop and hemp pest management. Hemp, while certainly not invincible, is considered resistant, or at least tolerant, to many diseases and pests. Whether you have an existing hemp farm or are considering stepping into this lucrative industry, having tips and ideas for how best to manage hemp insect pests is important.

1. Knowledge is (Hemp Pest Management) Power

While much is still unknown about hemp and how it resists or is affected by pests, some hemp pests have been identified. But not every pest is an economically impacting pest. The first step in the fight for control of hemp insect pests is understanding if it’s a battle worth fighting.

Another reason to closely monitor and understand pests’ impact on hemp plants is the possible effect on the ability to wholesale cannabis grown for its CBD. While it is not yet fully known or understood, there is a query as to whether hemp insect feeding will increase the level of tetrahydrocannabinol (THC).

This could create a potential issue, as the THC levels must remain below the set threshold of 0.3 percent in dry-weight CBD, as ruled in the 2018 Farm Bill. Elevated THC because of pests could render the harvest unsellable. And if the THC level is above 0.5 percent, not only is the entire crop subject to being destroyed, but a violation will be issued by the USA. Three violations in the course of five years could bar you from growing commercial hemp for five years.

Don’t let hemp insect pests interfere with your options of crops. And while there is a lot not yet fully known, a few pests have been identified as dangerous to a successful hemp crop. Know your enemy.

The corn earworm, Eurasian hemp borer, hemp mite, cannabis aphid, and Japanese beetle have all been deemed an economic threat, damaging to hemp, that should be mitigated.

2. Understand How Pests Cause Damage

Not all hemp insect pests are created equal— and depending on the hemp production you are growing, you should fully understand the risks each pest presents, as well as the necessary pest management approach to use against them.

The Japanese beetle, for example, readily feeds on the hemp flowers and is a potentially significant defoliator. Other beetles, such as flea beetles, seem to present a minor threat to the plants. As such, Japanese beetles are more costly to hemp raised for CBD or CBG yield as opposed to ones raised for their fiber.

It’s also important to fight the battle within your geographic area. While southern corn rootworms have the largest geographic territory, they are predominantly found east of the Rockies. Japanese beetles tend to stay east of the Mississippi.

Grasshoppers, particularly in eastern Colorado, have damaged hemp crops differently from other defoliators by causing extensive damage to the twigs and weakening the stems.

Different pests can also damage the hemp at various stages of its development. For instance, spider mites attack plants in an indoor/greenhouse environment but tend to dissipate when transplanted to the field. The hemp russet mite, on the other hand, can cause widespread damage, regardless of the plants being cultivated indoors or outdoors.


3. Integrated Pest Management (IMP)

Once you have an understanding of the potential pest threats to your crop, based on geography, the kind of hemp you’re growing, and the risks of certain pests’ ability to cause economic harm, you can develop a multi-pronged approach to hemp pest management. Because this is such a new-again industry, integrated pest management for hemp is also new, an ongoing work in progress. But from what we currently know, the following steps will help in your goal of a successful hemp crop.

Prevention: Preventing hemp pests like mites, aphids, borers, and corn earworm is the best and first line of defense. And while you may not be able to prevent all hemp insect pests, there are certainly some tactics you can employ to reduce the likelihood:

Quarantine and inspect new plants before introducing them to the larger crop population.

  • Reduce the desirable habitat of pests by ensuring good drainage.
  • Reduce standing water.
  • Do not plant your hemp field beside a cornfield.
  • Control weeds and overgrown vegetation.

Monitor: Keeping a close eye on your hemp crop and regularly inspecting it will allow you to minimize the impact of pests by voluntarily removing affected plants or treating them quickly to prevent spread.

Natural Predators: Introducing or attracting natural predators such as soldier bugs or lady beetles into your crop can keep hemp pests like aphids in check. Introducing plants like lavender among your hemp plants will attract these “good guys.”

Intervention: If additional help is needed to ward off damaging hemp insect pests, there is good news! The EPA has recently approved ten pesticides for commercial use in cultivating hemp. Nine of these are biopesticides, meaning they are either:

  • Biochemical — Naturally occurring or synthetic versions of naturally occurring substances to control pests.
  • Microbial — Microorganisms that control pests.
  • Plant-incorporated protectants — Pesticides naturally produced by plants, with added genetic material.
  • Biopesticides are derived from natural materials and are considered lower risk than traditional chemical pesticides.

Start Strong, Stay Strong

As the hemp industry continues to grow, more data will be gleaned as to what pests are potentially harmful to which kinds of hemp and in what environments. This ongoing collection of knowledge will lend itself to better hemp pest control and how to maximize hemp profitability.

One of the best things you can do to grow a hearty, robust crop of hemp is to start with a hearty, robust strain of hemp seeds. Want to know more about the right hemp strain for you? Reach out to High Grade Hemp Seed today.