Parasitism of soybean aphid by Aphelinus certus in Minnesota, 2011 to 2021, by Jonathan Dregni, Pamela Rueda-Cediel, Nicole Szajner, Joe Kaser, James Miksanek, Kelton Welch, Carl Stenoien, Robert Koch, George Heimpel. Presented to the 2022 conference of the North Central Branch of the Entomological Society of America.
Soybean aphid was first detected in North America in the year 2000, and rapidly became the most costly pest of soybean, prompting extensive insecticide use. The parasitoid Aphelinus certus was first detected in Connecticut in 2004 and by 2011 it was found in Minnesota; since establishment this parasitoid has been widespread including in neighboring states even at low aphid densities. Minnesota has shown higher aphid densities than other states in the region, which makes this an excellent place to study the dynamics of aphid biological control. Even in Minnesota the aphid has not regularly exceeded the spray threshold in the past 6 years, and we explore whether this can be attributed to the parasitoid.