Issue No. 18, Article 5/July 24, 2009
Soybean Aphid Densities Remain Low in Illinois Through Mid-July
Despite the very mild temperatures across Illinois this summer, soybean aphid densities remain low. This observation is based on the lack of confirmed economic infestations in producers' fields and an analysis of weekly sampling data from sentinel plots throughout the state. A review of the USDA PIPE (Pest Information Platform for Extension and Education) website confirms very low densities of soybean aphids across much of the north-central region of the United States through July 21. I encourage readers to check out this valuable website for information on both soybean aphids and soybean rust.
Even though we are in good shape right now with respect to this insect pest of soybeans, I encourage producers to remain vigilant and continue scouting their soybean fields and to be ready to respond if the economic threshold of 250 aphids per plant is reached, 80% of the plants are infested (R1 through R5 stage of development), and natural enemies are not adequately suppressing the aphid population.--Mike Gray