Alfalfa plant bug
This plant bug survives winter as eggs hidden in stems, and its young thrive far better on flowering alfalfa than on plants without blooms.
| Where | Alfalfa fields and farmland |
|---|---|
| Size | 7.6 to 9.5 mm body length |
| When | June to September |
The alfalfa plant bug is an elongated pale green to pale brown bug with two black spots on the pronotum and two brown lines running along the scutellum. A brown triangular mark sits at the centre of each wing case, and the legs are speckled with brown.
Adults appear from early summer through autumn and feed on the sap of alfalfa and a range of other crop and wild plants, piercing tissue with their mouthparts. Eggs laid in late summer overwinter inside plant stems and hatch the following spring.
Traits
Habitat
Farmland
Colour
Green, Brown
Active
Day
To people
Known mainly as a crop pest of alfalfa and cotton rather than a nuisance to people; does not bite or sting.
Activity through the year
Often confused with
Smaller at about 5 to 6 mm, more uniformly mottled brown or green, and lacking the distinct brown triangle and paired pronotum spots of the alfalfa plant bug.
Questions
Is the Alfalfa plant bug dangerous to people?
Known mainly as a crop pest of alfalfa and cotton rather than a nuisance to people; does not bite or sting.
When can you see the Alfalfa plant bug?
The Alfalfa plant bug can be seen from June to September, by day.
Plate retouched from a photo by janetgraham84new, CC BY 2.0, Wikimedia Commons Licence
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True bugs›Plant bugs›Adelphocoris
Last updated 2026-09-26. Every entry is checked against published sources.