Location: Sunflower and Plant Biology Research
Project Number: 3060-21000-047-010-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2021
End Date: Jul 31, 2023
(1) Assess gene flow among populations of the red sunflower seed weevil where the range of the pest overlaps with production of cultivated sunflower, and (2) Evaluate variation in areas of the weevil genome commonly associated with resistance to pyrethroid insecticides.
The red sunflower seed weevil (RSSW) is currently the most common and severe insect pest of sunflowers. Because sunflowers are rotated with other crops and RSSW are host-specific, weevils emerging from the soil each summer must move from where sunflower was grown last year to a different location planted to sunflower this year. This makes pest movement a key issue for both the pest and growers. Physical or chemical markers are realistically limited to measuring small-scale insect movement (< 1 km), meaning other methods must be used to assess weevil movement at scales relevant to sunflower growers. To evaluate RSSW movement, adults will be collected from sunflowers across several states, including one transect with several relatively close (5 km) sites. Molecular inversion probes (MIPs) or microsatellites will be used to assess population structure among weevil collections, providing an idea of gene flow (= movement) at both small and large scales. Also, because of recent concerns about possible resistance to insecticides, variation will be assessed in areas of the genome commonly associated with resistance to pyrethroids. The results will be important in determining which integrated pest management tactics are feasible for sunflower growers in the United States.