2014-15 Rapid Ag: Experimental Releases of a Newly-Approved Asian Biological Control Agent of the Soybean Aphid

November 10, 2014

Principal Leader

George Heimpel

Department

Entomology

Funding Awarded

  • 2014 Fiscal Year: $77,000
  • 2015 Fiscal Year: $77,000

The Problem

The soybean aphid remains a critical pest in MN and the region. Since its invasion from Asia in 2000, soybeans in the North Central United States have experienced massive increases in insecticide use.  This has led to increased costs for soybean farmers, damage to beneficial insects, vertebrate animals and humans, and increased release of greenhouse gases. 

Background

One of the most promising strategies to control soybean aphid permanently and sustainably is importation biological control – the introduction of one or more natural enemies from the native range of the aphid (Asia). Importation biological control has been deemed promising on the basis of studies showing that soybean aphid are well-controlled by insect predators and parasitoids in Asia and also the discovery of numerous parasitoid species in Asia that are not present in North America. The process of importation biological control against the soybean aphid has involved foreign exploration in Asia to identify prospective control agents, safety testing of these agents under quarantine conditions, and application for release permits from USDA APHIS for agents that are deemed safe and promising. We now have permits for two soybean aphid parasitoids following this procedure. 

The current research plan is based upon the recent permission from USDA to release another soybean aphid parasitoid from China: Aphelinus glycinis.

The USDA granted permission for the release of A. glycinis in October 2012. This is a highly promising species that has a better chance of establishing than previously imported insect predators  We believe that A. glycinis has the potential of suppressing soybean aphid to subeconomic levels. Laboratory studies done under quarantine conditions have shown that A. glycinis is a specialist on soybean aphid, that it is a voracious consumer of soybean aphids, and that it is easy to mass rear. The permit to release A. glycinis is the most exciting development in soybean aphid biological control in recent years and it is critical that we place appropriate levels of effort to maximizing the probability of establishing this parasitoid in Minnesota.

Objectives

1. Conduct experimental releases of Aphelinus glycinis.

      • Release experiments at experiment stations
      • On-farm releases using best practices

2. Characterize the interactions between Aphelinus glycinis and other parasitoids.

      • Cage studies involving 3 soybean aphid parasitoids
      • Co-parasitism studies involving 3 soybean aphid parasitoids
Soybean Aphid research St. Paul campus.

With permission of the USDA, George Heimpel and his team are now able to study Aphelinus glycinis, a natural predator of soybean aphids, in the field including on the St. Paul campus.