Corn Invertebrate Loss Estimates from the United States and Ontario, Canada — 2022

Invertebrate pests (namely insects, mites, and slugs) annually reduce corn yield in the United States and Canada. The abundance and impacts of these pests vary from year to year, and their effect on yield is based on many factors, including weather conditions, crop production practices, and hybrid selection and susceptibility to invertebrate feeding.

Extension specialists representing 25 corn-producing U.S. states and Ontario, Canada, estimated the percent yield loss from corn invertebrate pests. These reports account for more than 12.8 billion bushels (90.9 percent) of the total corn produced in the U.S. and Ontario in 2022 (Figure 1). The yield loss estimates include foliar, root, ear, and stalk feeding invertebrate pests.

This publication documents the impact of major invertebrate pests on corn production during 2022. Extension entomologists began tracking these data in 2021 and will revise estimates annually. It is important to note that methods for estimat­ing losses from invertebrate pests vary by state or province. The estimates may be based on statewide surveys, personal experience, and feedback from university extension personnel, industry representatives, and farmers.

Maximum yield before losses due to invertebrates was estimated for each state or province using this formula: (total harvested bushels/[{100 – percent estimated invertebrate pest loss}/100]). Total bushels lost per invertebrate pest were then formulated ([percent loss/100] x yield before estimated loss) for each state or province.

U.S. and Canadian farmers have expenses to control invertebrate pests of corn in the form of plant-incorporated protectant fees (included in the cost of seed and not easily estimable), seed-applied insecticides, and soil and foliar insecticides and acaricides. These expenses to prevent potential losses are not included in our calculations; thus, the values in this publication underestimate the impact of invertebrate pests in U.S. and Canadian corn production.

2022 Conditions and Corn Production

The U.S. produced 13.7 billion bushels of corn in 2022, while the province of Ontario, Canada produced 0.4 billion bushels. The 2022 cropping season was hot and dry across most of the corn-producing states. Above average temperatures were observed during pollination and grain fill in 2022 throughout much of the contiguous U.S., and multiple corn producing states experienced drought.

Estimated 2022 Invertebrate Losses

In 2022, invertebrate pests reduced corn yield by an estimated 7.3 percent across 25 states and by 2.2 percent in Ontario, translating into an overall loss of more than 982 million bushels. As in 2021, corn rootworms were estimated to cause the greatest yield loss overall (Figure 2). Other important invertebrate pests in terms of yield loss were twospotted spider mite, western bean cutworm, corn earworm, Banks grass mite, and grasshoppers. In Table 1, yield loss estimates for invertebrate pests reported in corn production in the U.S. and Canada are summarized.

Table 1. Estimated corn yield losses (thousands of bushels) due to invertebrate pests in 25 U.S. corn-producing states¹ and Ontario, Canada in 2022.

¹ Alabama, Arkansas, Colorado, Delaware, Georgia, Illinois, Iowa, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New York, North Carolina, North Dakota, Ohio, South Carolina, South Dakota, Tennessee, Texas, and Wisconsin. ² Diabrotica barberi, D. virgifera virgifera, D. undecimpunctata howardi, and D. virgifera zeae. ³ Chinavia hilaris, Euschistus spp., Halyomorpha halys, and Nezara viridula. ⁴ Systena frontalis (SD) and possible Popillia japonica (adult) injury to silk and ear tip allowing nitulid entrance (KY). ⁵ Popillia japonica (immature) and Phyllophaga spp. ⁶ Nephelodes minians, Feltia jaculifera, Apamea devastator, Euxoa detersa, and Peridroma saucia. ⁷ Rhopalosiphum padi, R. maidis, and Aphis protaphis middletonii. ⁸ Colaspis brunnea and Colaspis crinicornis. ⁹ Choristoneura parallela and Xenotemna pallorana.

Invertebrate Pests by Production Region

The states reporting data from the western corn-growing region accounted for 69.5 percent of corn production in the U.S. and Ontario. Corn rootworms caused the most injury in this region (Table 2), due to the high amount of intensive continuous corn and Bt resistance in rootworm populations. Mite pests and ear-feeding caterpillars caused the greatest estimated yield losses after corn rootworm.

The states reporting data from the Great Lakes region accounted for 13.7 percent of corn production in the U.S. and Ontario. Similar to the western region, corn rootworms caused the greatest amount of estimated yield loss (Table 3). Seedcorn maggot, black cutworm, European corn borer, and grasshoppers caused the next greatest losses, in descending order. In this region, it is estimated that 2.3 percent of corn yield was lost due to invertebrate activity.

The states reporting data for the southern region represented 7.7 percent of the total corn produced in the U.S. and Ontario in 2022. Overall, losses due to corn invertebrate pests across southern states were very low (1.3 percent) (Table 4) compared to the western corn-growing region (8.6 percent) in 2022. Stink bugs caused the greatest yield loss in the southern states, followed by Banks grass mite, twospotted spider mite (Figure 3), southwestern corn borer, and corn rootworms.

Table 2. Estimated corn yield losses due to the five most significant invertebrates in western corn-growing U.S. states¹ in 2022.

¹ Colorado, Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, and South Dakota. ² Diabrotica barberi, D. virgifera virgifera, and D. undecimpunctata howardi.

Table 3. Estimated corn yield losses due to the five most significant invertebrates in the Great Lakes region of the U.S.¹ and Ontario, Canada in 2022.

¹ Michigan, New York, Ohio, and Wisconsin. ² Diabrotica barberi, D. virgifera virgifera, and D. undecimpunctata howardi.

Table 4. Estimated corn yield losses due to the five most significant invertebrates in southern U.S. states¹ in 2022.

¹ Alabama, Arkansas, Delaware, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, and Texas. ² Chinavia hilaris, Euschistus spp., Halyomorpha halys, and Nezara viridula. ³ Diabrotica barberi, D. virgifera virgifera, D. undecimpunctata howardi, and D. virgifera zeae.

Disclaimer

The invertebrate pest loss estimates in this publication were provided primarily by extension specialists from across the U.S. and from Ontario, Canada. This information is only a guide. The values in this publication are not intended to be exact measures of corn yield losses due to invertebrate pests, since they were not quantitatively measured. Participants assume no liability resulting from the use of these estimates. Hence, these losses should be approached with caution when examined for a particular state. However, they can be useful to compare general trends across years or across regions within a given year. Values reported in this document were accurate as of publication date and do not reflect corrections or updates occurring since that time.

Acknowledgements

Data Compilation

Dominic Reisig, North Carolina State University, Adam Sisson Iowa State University; and Daren Mueller, Iowa State University

Authors

Dominic Reisig, North Carolina State University; Katelyn Kesheimer, Auburn University; Nick Bateman and Glenn Studebaker, University of Arkansas; Ron Meyer, Colorado State University; Francis Reay-Jones, Clemson University; Ken Wise, Cornell University; David Owens, University of Delaware; G. David Buntin, University of Georgia; Jocelyn Smith, University of Guelph; Nick Seiter, University of Illinois; Erin Hodgson and Adam Sisson, Iowa State University; Anthony Zukoff, Kansas State University; Raul Villanueva, University of Kentucky; Tyler Towles, Louisiana State University; Kelly Hamby and Maria Cramer, University of Maryland; Chris DiFonzo, Michigan State University; Bill Hutchison and Bruce Potter, University of Minnesota; Whitney Crow, Mississippi State University; Mandy Bish, University of Missouri; Jeff Bradshaw and Julie Peterson, University of Nebraska; Patrick Beauzay and Janet Knodel, North Dakota State University; Kelly Tilmon, Ohio State University; Tracey Baute, Ontario Ministry of Agriculture, Food and Rural Affairs; Adam Varenhorst, South Dakota State University; Sebe Brown, University of Tennessee; David Kerns and Pat Porter, Texas A&M University; and Emily Bick and Shawn Conley, University of Wisconsin-Madison. 

Reviewers

Daren Mueller, Iowa State University; Travis Faske, University of Arkansas; and Kiersten Wise, University of Kentucky.

Production data from the United States Department of Agriculture-National Agriculture Statistics Service and the Statistics Canada. Climate information from the National Oceanic and Atmospheric Administration-National Center for Environmental Information.

United States Department of Agriculture National Agricultural Statistics Service. Quick Stats Database. Accessed 20 March 2023.

Statistics Canada. Table 32-10-0359-01 Estimated areas, yield, production, average farm price and total farm value of principal field crops, in metric and imperial units. Accessed 20 March 2023.

Sponsors

In addition to support from United States Department of Agriculture - National Institute of Food and Agriculture, this project was funded in part through the National Corn Growers Association and the Grain Farmers of Ontario through the Sustainable Canadian Agricultural Partnership (Sustainable CAP), a federal-provincial territorial initiative.