The U.S. is one of the world’s top corn producers. In 2023, corn production in the U.S. reached a record of more than 15.3 billion bushels in a total harvested area of 86.5 million acres. In 2024, projections indicated around 14.8 billion bushels of corn, which is expected to account for approximately 35% of global corn production. Field corn accounts for 99% of the country’s acreage, with the remaining corn acreage cultivated with sweet corn, popcorn, and other specialty varieties for fresh or processed markets. The total production value of U.S. corn in 2022 was estimated at $97.2 billion. 

Corn yield is inconsistent across regions, and competition with a variety of insect pests contributes to this variability. Together with weather, planting conditions, and competition with weeds and diseases, arthropod pests are critical sources of economic yield losses. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), and two species of corn rootworms, Diabrotica spp. (Coleoptera: Chrysomelidae), have been historical key pests of corn in the U.S., with each having an estimated impact of over $1 billion annually due to the management costs and yield losses. Several additional lepidopteran pests have been listed as economic pests of corn in the U.S. Helicoverpa zea (Lepidoptera: Noctuidae), commonly known as corn earworm, can be a serious pest to sweet corn (Olmstead et al. 2016), particularly when produced for the fresh market. Temperatures influence the population dynamics and survival of this species, and collaborative multistate work has proposed three overwintering zones in North America: the southern range (below 35^oN), where H. zea survives winter temperatures; the transitional zone, where overwintering survival varies with yearly temperatures; and the northern limits, where winter temperatures are lethal to H. zea. In field corn, this pest is commonly present in southern states, and injury is mostly limited to kernel feeding on the tip of the ear, which usually does not cause an economic impact (Reay-Jones 2019). However, due to the highly polyphagous behavior of the species, corn serves as an important source of infestation for other economic crops which may facilitate migration and colonization of crops on a continental scale in the U.S. (Paula-Moraes et al. 2024). Fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), also poses an economic threat to the U.S., especially to sweet corn production, with the potential to reduce yields by 20-40% in some cases, due to the feeding on leaves, stems, and kernels. This species is also a strong flier, being the southeast region hub for genetic flow (Paula-Moraes et al. 2024) and reaching northern latitudes every summer (Tessnow et al., 2023). Another economic pest associated with corn is western bean cutworm, Striacosta albicosta (Lepidoptera: Noctuidae). The first reports of this species come from the beginning of the last century, and it has since extended its geographical distribution northward and eastward, from the western Great Plains into the corn-producing regions of the Midwest and the eastern U.S. and Canada. A study found that the mean yield loss from a single larva per corn plant was 945.52 kg/ha (15.08 bu/acre) (Paula-Moraes et al. 2013).

Western corn rootworm, Diabrotica virgifera virgifera, and northern corn rootworm, D. barberi, make up the most economically important insect pest complex in corn, particularly in the western portion of the U.S. corn belt (Wechsler and Smith, 2018). While both species are capable of overcoming crop rotation as a control strategy (Gray et al. 2009; French et al. 2014), corn rootworm population densities and subsequent yield losses are greatest in areas where continuous corn production is prevalent. These species have a long history of overcoming pest control tactics such as insecticides, crop rotation, and transgenic traits through the development of resistant populations (Gray et al. 2009). The broad deployment of transgenic hybrids expressing multiple toxins of the bacteria Bacillus thuringiensis (Bt) for control of corn rootworms has contributed to large-scale reductions in rootworm population densities in much of the corn belt (Tinsley et al., 2018). However, the ongoing development of resistance to these transgenic hybrids in both western and northern corn rootworms poses a substantial pest management challenge to U.S. corn production.

Transgenic plants expressing Bt toxins have been broadly adopted in the U.S. to control O. nubilalis and other lepidopteran pests, in addition to rootworms. The Bt corn acreage has since increased, with more than 80% of all corn planted in the U.S. being genetically engineered in 2024, primarily with Bt traits for insect resistance (National Agricultural Statistics Service, 2024). Currently, several commercial traits are available to manage the aforementioned lepidopteran and coleopteran pests associated with corn, contributing to decreasing the use of insecticides and promoting IPM. However, several cases of increased resistant populations of target pests to Bt traits in corn and novel pest problems not targeted by Bt technology have underlined the need to continue research and Extension work. The overall contribution of supporting the diversification of options for pest management is the sustainability of corn production in the U.S.

In addition, other pest species are associated with corn production and are considered in IPM programs. For instance, a complex of stinkbug species (Hemiptera: Pentatomidae), including the brown marmorated stinkbug, Halyomorpha halys, and the brown stink bug, Euschistus servus, have been reported to affect corn crops across various regions in the U. S. The impact can vary year by year, but it is usually the top pest of corn in the southern U.S. (Reisig et al. 2024). One of the most identifiable symptoms of this pest is ear deformity, commonly named “banana-shaped” ear.

The NC246 committee addresses critical pest issues previously discussed and represents a collaborative effort between members working with corn on a continental scale in the U.S. The committee’s work has a long history of working with above and below-ground corn pests. Two committees were initially established. The initial NC205 (Ecology and Management of European Corn Borer and Other Lepidopteran Pests of Corn), established in 1953, and the NCCC46 (Development, Optimization and Delivery of Management Strategies for Corn Rootworms) started co-locating their annual meeting in the 1990s with an increasing interaction between members from the two committees. In 2016, the current NC246 committee was formed, merging the two committees and promoting research and Extension collaborations addressing the corn pest complex and emerging problems, such as insect resistance to Bt transgenic corn targeting corn rootworm and lepidopteran pests.