Growers of carrot, parsley, and celery in the Great Lakes Regions of North America continue to suffer serious yield losses from carrot weevil damage, despite heavy reliance on insecticides and use of IPM strategies. Currently, there have been no investigations into the use of insect-resistant crop cultivars as an IPM tactic to reduce carrot weevil damage.
We planted seven commercial carrot cultivars at two Indiana field sites and one Ohio field site in 2021 and conducted biweekly surveys for foliar arthropods and carrot weevil egg scars during June and July. Carrot weevil pressure was lowest at the Indiana field sites, with less than 35 cumulative egg scars at each site and correspondingly low levels of root damage at harvest. Carrot weevil pressure was highest at the Ohio field site, with 112 cumulative egg scars across all varieties. However, two cultivars, ‘Resistafly’ and ‘Danvers 126’ exhibited only 6 cumulative egg scars; the fewest of all cultivars at this site. Furthermore, we only observed significant differences in root damage between ‘White Satin’ and ‘Cosmic Purple’ cultivars in Ohio. We collected 22,670 insects during the 2-month sampling period across all field sites. We observed a wide diversity of arthropods across all carrot cultivars, however the lowest number of pest insects, specifically hemipteran pests, were collected from ‘Resistafly’, regardless of site location. These results suggest that existing carrot cultivars, particularly ‘Resistafly’, differ in qualities that influence insect activity and warrant further investigation for sources of resistance to insect pests like the carrot weevil.
