Variation in Soybean Aphid (Hemiptera: Aphididae) Biotypes Within Fields

Area of Science:

• Agricultural Entomology
• Pest Management
• Genetics

Background:

• Soybean aphid (Aphis glycines) is a significant North American pest since 2000.
• Multiple soybean aphid biotypes have emerged, overcoming some resistance genes.
• Limited data exists on biotype variation within individual soybean fields.

Purpose of the Study:

• To investigate the variation of soybean aphid biotypes within single townships and fields in Minnesota.
• To assess the prevalence of different soybean aphid biotypes in localized agricultural areas.

Main Methods:

• Collected 28 soybean aphid isolates from seven soybean fields in Renville and Kandiyohi Counties, Minnesota.
• Screened isolates using a panel of resistant and susceptible soybean indicator lines.
• Characterized biotypes based on their reactions to the indicator lines.

Main Results:

• Multiple soybean aphid biotypes were identified within single fields, with up to three biotypes found in one field.
• Five out of seven fields harbored at least two distinct biotypes.
• Three isolates exhibited reactions inconsistent with previously identified biotypes.

Conclusions:

• Soybean aphid biotype distribution is highly variable even within small geographical areas.
• Characterizing local biotypes is crucial for effective resistance gene deployment.
• Developing soybean cultivars with pyramided resistance genes can enhance pest management and sustainability.