Corn Aphid

Constraint – Corn aphid

Appearance 

• Pale blue-green to dark olive green aphid with a purple area at the end of the body

• Adults vary in length from 1.5 mm to 3 mm

Symptoms

• Cereal aphids reduce yields primarily by transmitting Barley yellow dwarf virus

• Direct feeding damage by aphids can impact on plant productivity by decreasing the number of tillers, seed set and grain filling

Damage

• Yield penalties from BYDV may be medium with a large infestation of aphids

• Direct feeding damage by aphids is generally low

Control 

Chemical control may be warranted to prevent direct feeding damage by aphids, and infection by BYDV. An effective rate of insecticide should be applied between 3-8 weeks after emergence. Natural enemies can exert effective control on small to moderate populations of aphids. It is worth considering a specific aphicide (eg pirimicarb) if natural enemies are active in the crop and chemical control is required early in the season. 

Links and Resources

I Spy Manual - Corn aphid Page 82. Description, confused with/similar to, distribution, pest status, risk period, host range, damage, monitoring, and sampling. Published 2012.

Insectopedia - Corn aphid Description, biology, damage done to crops, monitoring, sampling, and control. Established 2000.