Characterizing the identity and seasonality of common arthropods on CBD hemp in northern Indiana

  

     As industrial hemp acreage throughout the United States has grown, there is an increasing need for research-based information towards effective pest management in this crop. A key pest group is insects, which may attack hemp and cause reductions in production and yield. However, knowledge of regional insect communities found on outdoor hemp is still limited. A critical initial step in growing our understanding is to identify potential pests, predatory (beneficial) insects, and likely visiting insects that occur in hemp systems throughout the production season. To address this knowledge gap, we conducted weekly and biweekly visual scouting of outdoor-grown CBD hemp plants over two summer production seasons at three sites in Indiana to characterize the identity and seasonality of potential pest, predatory, and visiting insects observed on plants. 

     Across all of our sites, we made 1493 insect observations consisting of 60 taxonomic families across 13 orders. The most common potential pests observed were aphids, whiteflies, and leafhoppers, while the most common predators were long-legged flies, spiders, and hover flies, respectively. Other herbivorous insects such as red-headed flea beetles and tarnished plant bugs were observed feeding on hemp plants. However, many others, such as Japanese beetles and brown marmorated stink bugs, were not. Based on these results, we recommend that hemp growers in our region scout for insects on a twice-weekly basis, beginning at germination or 1 week following transplant.

     These findings will help inform growers about the timing of scouting for insects on outdoor grown CBD hemp, as well as when key potential pests and beneficial insects are likely to be present so management decisions can be focused accordingly. This work further serves as a foundation for future examinations of insect pest management in hemp, including predator-prey interactions that may be leveraged for biological control strategies in indoor production.