Greenbug

Definition

A common name for Schizaphis graminum, a small aphid in the family Aphididae that is a major pest of cereal crops and forage grasses. Adults are pale green with a darker green dorsal stripe, possess short antennae and cornicles, and reproduce parthenogenetically, producing multiple generations per growing season. The species transmits plant viruses including barley yellow dwarf virus and causes direct damage through phloem feeding that produces characteristic yellow or red leaf spots. Native to Eurasia, it has spread globally with agriculture and remains economically significant in wheat, sorghum, and barley production.

Etymology

From the bright green coloration of live specimens and the historical term 'bug' for sap-feeding Hemiptera.

Example

In the southern Great Plains, greenbug outbreaks are monitored using suction-trap networks and degree-day models to time insecticide applications before economic thresholds are reached in winter wheat.

Synonyms

• wheat aphid
• green aphid

Related Terms

• aphid
• Schizaphis graminum
• barley yellow dwarf virus
• Economic threshold
• Parthenogenesis
• cornicle
• sorghum midge
• Russian wheat aphid
• Integrated Pest Management

Usage Notes

The name is sometimes applied loosely to other green aphid species, but in agricultural entomology it specifically denotes Schizaphis graminum. Distinguish from the 'green peach aphid' (Myzus persicae), a polyphagous pest of broadleaf crops. Populations are categorized as biotypes based on host-plant resistance-breaking ability, with biotype E historically significant in the United States.