Aphids are small, soft-bodied insects that are generally pale green and pear-shaped, however colour may range from black to red. Aphids feed by piercing plant tissue and sucking out juices. This is primarily done on leaves and shoots. This feeding may cause damage and lead to wilting or leaf distortion. 

What to Look For

  • 1-3 mm longAphids
  • Long antennae
  • Winged or wingless
  • Tend to feed in groups
  • Pair of “projections” near the rear end of the abdomen   

Prevalence and Scouting

  • Aphids may develop high populations in warm and humid conditions
  • Aphids will feed on a variety of host plants, including:
    • Field peas
    • Soybeans
    • Barley
    • Wheat
    • Oats
  • Time of scouting varies between each crop type, for example:
    • Field peas: beginning of flowering
    • Soybeans: July and August
    • Cereals: June until soft dough phase


A variety of beneficial insects can help control aphids:

Thirteenspotted Lady Beetle

  • Along with the sevenspotted lady beetle and harlequin lady beetle, thirteenspotted ladybeetle feeds on aphids
  • Studies have shown that adults may consume an average of 110-160 aphids in 24 hours.


  • Lacewings eat aphids and mites, along with the eggs and larvae of the Colorado potato beetle and diamondback moth

Damsel Bug

  • Damsel bug eat aphids, small caterpillars, mites, and moth eggs

Related Links

Bug Series: How to Deal with Aphids