This is the time of year when much of the insect pest management in crops has been completed… early season pests have come and gone and weather conditions are ideal for crops to grow and recover from most minor damage.
Still, there are many producers who add a pyrethroid insecticide with fungicide sprays at R1 in corn or R3 in soybeans. These insecticides are very inexpensive and can supply peace of mind. After all, an “insurance” spray may negate the need for even entering the field to scout for insects, and take care of any emerging problems before they become serious.
However, it’s worth asking what pests are actually out there? As covered in previous Pest&Crop articles, that answer has changed a lot over the last couple of decades. For a snapshot of corn entomologists’ estimates on 2024 pest prevalence and severity, please check out this article from Crop Protection Network.
A screenshot from this link appears below. You’ll note that corn rootworms still rule the roost, in terms of both prevalence and risk to yield. But look more closely at the loss estimates comparing the Great Lakes states (including Indiana), Table 2, with the corn-producing states out west, Table 3… it’s a very different story and over 10X difference in the yield loss estimates. The pest complex is different as well.
Admittedly, this is somewhat anecdotal, and based on the estimates of extension entomologists responding to calls, conducting research/monitoring programs, etc., and these West vs. East differences are a theme that’s always been somewhat true. But it seems that this is becoming more pronounced in recent years and opening up opportunities to explore different ways to tackle insect IPM.
With all that in mind, please pay some extra attention to fields in the next week or two as crops reach reproductive stages and start receiving insecticide sprays. What insects are out there? Are they causing defoliation or any other measurable damage? How widespread are the infestations?
I will present a survey on these topics in this space to get your feedback in the coming weeks!
