Cowpea Aphid (Kansas Alfalfa)

Scouting time

These large, dark aphids generally feed near the tips of infested stems and have been sporadically reported from alfalfa fields since 1999. Damage is similar to that caused by the pea aphid, and thresholds are likely to be comparable. Significant populations developed in 2009 and 2012.

Sampling method

None listed.


None listed. 

Chemical control




 0.014 to 0.025 lb. a.i./acre (2.2 to 3.8 fl. oz./acre)

Alpha-cypermethrin (Fastac EC)

 0.022 lb. a.i./acre (2.8 fl. oz./acre)

Beta-cyfluthrin (Baythroid XL)

 Check label, but generally 1 to 2 pints/acre


Non-chemical controls

None listed. 

Content authors


This content may not be suitable for states other than Kansas.