Succession, Diversity, and Abundance of Insects on Industrial Hemp (Cannabis sativa L.) and the Effect on Yield

Industrial hemp (Cannabis sativa L.) is now being cultivated in the United States over a much wider geographic area due to the recent legalization of the crop. As production increases, knowledge on the insect communities associated with hemp will be critical to understanding beneficial and pest insects that affect the crop at different phenological stages. An insect study was conducted in 2021 at North Carolina A&T Research Farm with four hemp cultivars (CFX-2, Canda, Joey and Henola). Insect data were collected weekly using direct visual counts and vacuum sampling. The goal was to 1) determine insect abundance and diversity on industrial hemp and 2) assess the impact of pests on yield. The results indicate that several insect pests including leafhoppers, Japanese beetles, brown marmorated stinkbug, leaf footed bugs, tarnish plant bug, flea beetles and cucumber beetles and beneficial insects including honeybee, bumble bees, sweat bees, hoverfly, big-eyed bug and lady beetles were recorded on all the hemp cultivars. During the first three weeks of sampling leafhoppers were the most prevalent. By week five, there were more bumblebees, honey bees and big-eyed bug. Insect diversity and abundance varied weekly among the cultivars. Joey recorded the highest seed yield. Findings from this study can be used to better understand how insects may affect this crop. Understanding the role of insect pests and beneficial insects will lead to mitigation plans as part of a robust management strategy for increasing the yield and quality of hemp crop.