Scott Tilley: Farmers battle beetles

Published 12:00 am Monday, April 25, 2011

By Scott Tilley
For the Salisbury Post
Grain farmers face many challenges through the winter and spring growing season.
One of the challenges many Rowan County farmers take on is the battle of crop destroying pests such as the cereal leaf beetle. Cereal leaf beetles can be extremely destructive to a crop if not addressed in time.
This enduring insect can feed on wheat, barley and oats. Additionally, adults can feed on corn through the early summer months, but cause no real damage and have no impact on corn yield.
The life cycle of the cereal leaf beetle is very simple. Adult beetles overwinter in fallen leaves and can live in ground stover and other plant debris along forested field edges. As the warm spring months begin to emerge, the adults will colonize and lay eggs in small grain crops come the month of late March and April.
Adults lay their eggs along the veins of healthy green leaves. These eggs are easy to spot as they have a yellow to orange glow color.
Though their color may give them away, they are very small and may not be seen unless you know what to look for. According to North Carolina State University Extension entomologists, these eggs can hatch within five days.
Larvae then begin to grow. Newly developed larvae, as well as full-grown larvae, take on the same characteristics having six legs towards the head with a large fat abdomen.
All larvae have a brown to black color, but are most identifiable by the black mucus and fecal material that cover their bodies. It is this stage within the life cycle that farmers must be aware of the insect’s destructive nature.
Larvae eat the leaves of small grains. Larvae consume the upper leaf green tissue. Because of this, plants take on a white pale appearance. The plant fails to maintain the process of photosynthesis and therefore will not bear fruit. The plant will eventually die.
Once summer has arrived, the larvae that have survived will dig into the ground and will begin their transformation process into adulthood. Adults are 3/16 of an inch long with a black metallic head and wings. The legs and front thorax are red.
Though farmers usually use preventive measures to avoid the insect, cereal leaf beetle is common and is usually treated every year using a synthetic pyrethroid pesticide. For more information, call the Rowan County Extension Center at 704-216-8970.
Scott Tilley is extension agent who specializes in field crops.