O’Neal lab

Photograph of Dr. O'NealDr. O’Neal studies the insect pests of soybeans and the beneficial insects that can help soybean production. His lab is studying if soybean yield is increased when plants visit soybeans in bloom. In addition, he is studying ways to improve the abundance and diversity of bees in the farmland. The following are results and on-going experiments being conducted by his lab.

Activities:

• Survey of bees in corn and soybean fields.

• Increasing bee abundance in crops by planting a border of native, perennial flowering plants (i.e. prairie).

• Develop methodology for sampling bees in cropfields, determine which species are visiting corn and soybean flowers and collecting pollen.

• Determine the impact of bee pollination on soybean yield.

• Determine if soybean pollen and nectar are beneficial to honey bee health.

Findings:

• At least 40 species of bees (including honey bees) are found in Iowan corn and soybean fields. Most of these are native, solitary bees. Of the most abundant species, ~20-30% were found with corn or soybean pollen.

• Prairies constructed with flowering perennial plants are a source of bees, and can provide a flowering resource throughout the season.

• Our best bet for constructing prairies for bees is to select a few species (5-12) of plants that are most attractive to bees and plant in a mixture that produces flowers throughout the season.

Take home messages:

• Although corn and soybean do not need bees to produce seed, these crops harbor a large, diverse community of bees including honey bees.

• It is not clear if the remarkably diverse community of bees is in decline because there is limited data on the abundance of these species over time. Despite this uncertainty, most of the insecticides used in corn and soybeans are toxic to bees.

Changes have been made to the labels of select insecticides (i.e. neonicotinoids) by the EPA to limit the exposure of bees to them. Discussion is underway to expand these changes to other classes of insecticides which are also harmful to bees.