Soybean aphid

Definition

A small sap-sucking hemipteran, Aphis glycines (family Aphididae), that is a major pest of cultivated soybean (Glycine max). Native to Asia and invasive in North America since 2000, it reproduces parthenogenetically on soybean during the growing season and overwinters on buckthorn (Rhamnus spp.) as its primary host. Dense colonies cause direct damage through phloem feeding and indirect harm via transmission of viral pathogens such as Soybean mosaic virus.

Etymology

From 'soybean' (the host plant Glycine max) + 'aphid' (the common name for small sap-sucking insects in family Aphididae).

Example

In the upper Midwest United States, soybean aphid populations can double every 1.5–2 days under favorable conditions, reaching economic thresholds of 250 aphids per plant that trigger insecticide applications.

Synonyms

• Aphis glycines

Related Terms

• Aphididae
• Parthenogenesis
• host alternation
• phloem feeder
• Economic threshold
• Invasive species
• Soybean mosaic virus
• Integrated Pest Management

Usage Notes

The common name refers specifically to Aphis glycines, not to any aphid found on soybean; other aphid species occasionally colonize soybean but are not designated 'soybean aphid.' In North American agricultural literature, the term often carries connotations of invasion biology and integrated pest management rather than simply taxonomy. The species exhibits heteroecy (host alternation) between buckthorn (primary host, sexual reproduction) and soybean (secondary host, asexual reproduction), a life-history pattern critical to its management.