D3065: The impact of pollen and nectar availability on insect communities of cultivated sunflowers

Monday, November 11, 2024

9:00 AM – 5:00 PM MST

Location: Phoenix Convention Center, Exhibit Hall 6, PCC

Presenting Author(s)

Grace M. Lewis (she/her/hers)

Graduate Research Assistant
North Dakota State University
Moorhead, Minnesota

Co-Author(s)

DP

Deirdre A. Prischmann-Voldseth

Professor
North Dakota State University
Fargo, North Dakota
Jarrad R. Prasifka

Research Entomologist
USDA-ARS
Fargo, North Dakota

The availability of floral rewards (i.e., pollen and nectar) influences insect visitation to flowering plants such as cultivated sunflowers (Helianthus annuus L.). Wild bees are attracted to sunflowers with greater nectar accessibility and where pollen is present, although how floral rewards affect other insect visitors is understudied. Many insect pests of sunflower heads feed on pollen as larvae and many natural enemies consume pollen and nectar in addition to prey. We established a field experiment using near-isogenic sunflower lines varying in pollen availability and lines differing in floret length (nectar accessibility) to determine how pollen and nectar availability affect visitation by bees, pests, and natural enemies. There were four replications of six treatments: male-fertile (pollen present) with short florets, cytoplasmic male sterile (CMS, pollen absent) with short florets, male-fertile with long florets, CMS with long florets, and two control groups, one wild line and one line with long corollas. The insect community was sampled using passive methods, yellow sticky traps and Ckyuna fly traps, and active methods, by shaking heads in cloth bags and capturing insects with vials. We expect that insect visitation will be greatest in the male-fertile lines with short florets. The results from this experiment will elucidate how floral rewards affect different insect functional groups and could be used to enhance pollinator-plant interactions, minimize insect pest damage, and reduce the use of pesticides through the attraction of natural enemies in crops.