Bag to Bin

It's that time of year to be scouting for insects. Both corn and soybeans face different struggles when it comes to insect pressure. A common and important insect for corn is the corn rootworm beetle. Corn rootworm starts as larvae in the soil and feeds on corn roots. It emerges as a beetle around late June to early July and feeds on silk. They can cause extreme damage to the crop. Because this insect can be so devastating, there are ways to monitor and see what pressure is like out in your field. 

Doing corn rootworm digs is one way to get an idea of early pressure. By digging up a corn plant and placing it in a bucket of water, this will allow larvae to float to the top and you can then see how many are on each plant. Another way to monitor pressure is by placing sticky traps out in your field. Place them right above the ear on the plant and check them a week later to see what activity is happening. WinField United says the threshold for corn rootworm is 0.5-1 insect per plant. It is important to consider different management techniques depending on your farming operation.

If you have acres that are corn on corn, using a hybrid that has below-ground insect protection is a way to enforce protection. SmartStax or Qrome products provide that below-ground protection. In our plots, we have DKC56-65SS, a 106-day hybrid and B98R95Q, a 98-day hybrid, that both offer below-ground protection to defend against corn rootworm larvae. By being able to offer both SmartStax and Qrome technology, NuWay Agronomy can be your one-stop shop for whichever genetic background you prefer.

While grasshoppers, spider mites, and aphids are not unique to soybeans, they do pose a threat and can cause economic damage. A significant population of grasshoppers commonly starts to show up on soybean foliage in July and August when their normal feeding habitats (like ditches and grass areas) are being mowed. They will start to infiltrate field edges and defoliate leaves which reduces photosynthetic activity and overall can affect yield. Spider mites are another pest that feeds on soybeans. They thrive in years that are hot and dry. They feed on soybeans by sucking nutrients out of the leaf leaving a yellow spot also known as leaf stippling. Intense feeding will show the leaves becoming yellow to brown or bronze. Like grasshoppers, the damage is noticed on field edges first. Finally, soybean aphids can also cause damage. Like spider mites, aphids feed by sucking mouthparts that extract contents out of the leaf. This can lead to a reduction in growth rate, pod counts, and overall yield. The economic threshold is 250 aphids per plant, with a greater impact in the R1-R4 stages.