About

Brian Nault is a Professor in the Department of Entomology at Cornell University, specifically affiliated with Cornell AgriTech. His research focuses on insect pest management of potatoes, vegetables, and field crops, as well as plant resistance to insects. As a faculty member, he contributes to the understanding and development of biological control strategies and integrated pest management practices. His work aims to address significant challenges in agriculture related to pest control, emphasizing sustainable and effective solutions.

Research topics

• Botany
• Biology
• Agronomy
• Ecology
• Agroforestry
• Horticulture
• Biotechnology
• Veterinary medicine
• Genetics

Selected publications

• Composition and relative abundance of <i>Delia</i> spp. (Diptera: Anthomyiidae) infesting onions in selected onion-producing regions

  Environmental Entomology · 2026-01-31

  articleSenior author

  In the Great Lakes and Pacific Northwest regions of North America, maggots (Diptera: Anthomyiidae) threaten the production of dry bulb onion (Allium cepa L.). Onion maggot (Delia antiqua [Meigen]) is considered the primary Delia spp. pest in the Great Lakes, whereas seedcorn maggot (Delia platura [Meigen]) is considered most common in the Pacific Northwest. Bean seed maggot, Delia florilega (Zetterstedt), is also reported to infest onions, but has not been detected widely in these regions. Where these Delia spp. co-occur, D. platura/D. florilega are presumed to infest onions before D. antiqua, but this also has been poorly documented. To address these assumptions, larvae from infested onion plants were identified to species from 2022 to 2024. We hypothesized that D. antiqua and D. platura would be the predominant Delia spp. in the Great Lakes and Pacific Northwest, respectively, and that D. platura would infest onions before D. antiqua where they co-occur. Results indicated that D. antiqua was most common in the Great Lakes (87% of Delia spp.) and in eastern Oregon/western Idaho (USA) (79% of Delia spp.), but sample sizes were too small to make inferences about northern California and eastern Washington. Delia florilega was not detected in our study. Delia platura was most prevalent infesting onions early in spring, whereas D. antiqua was dominant in late spring and early summer. Our findings document Delia spp. composition and phenology in selected onion production regions and will inform regionally tailored monitoring and pest management strategies.

  PublisherDOI

• Managing onion thrips in onion using co-applications of insecticides and chlorothalonil, 2025

  Arthropod management tests · 2026-01-01

  articleSenior author
  PublisherDOI

• Spraying Cry1A.105 + Cry2Ab2 Bt sweet corn has marginal benefit for <i>Helicoverpa zea</i> (Lepidoptera: Noctuidae) suppression

  Journal of Economic Entomology · 2026-04-28

  article

  Management of corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae) in fresh-market sweet corn requires multiple, precisely timed applications of effective insecticides. An alternative method to manage H. zea is sweet corn hybrids that express Bacillus thuringiensis (Bt) toxins, but this approach has become limited because H. zea populations have developed resistance to multiple Bt toxins. We hypothesized that spraying a marginally performing Bt hybrid with an effective insecticide would provide a level of H. zea control that neither approach could achieve independently. To test this idea, we compared H. zea control using Cry1A.105+Cry2Ab2 Bt sweet corn treated with chlorantraniliprole following either a 7, 4, or 2-3 day silk-stage spray schedule with control following the same spray schedule and the non-Bt isoline. This study was conducted in high and low H. zea pressure environments in 2024 and 2025. Results showed that the combination of insecticidal sprays and the Bt hybrid provided minimal additional benefit relative to the sprays alone. We did find that weekly applications of chlorantraniliprole resulted in measurable reductions in H. zea damage, but the benefit of additional sprays dissipated with increasing frequency. This effect was most apparent where H. zea pressure was low and there was no statistical separation among spray interval treatments. Our results highlight the challenge of producing undamaged sweet corn, even when a Bt hybrid is treated intensively with an insecticide. Outcomes show that existing action thresholds may need revision to include additional variables that are sensitive to current input and damage costs.

  PublisherDOI

• Optimizing application timing and frequency of a novel <scp>dsRNAi</scp> ‐based insecticide for Colorado potato beetle management

  Pest Management Science · 2025-10-22

  articleOpen accessSenior author

  BACKGROUND: The Colorado potato beetle (CPB), Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), is as important pest of potato, Solanum tuberosum, in the U.S. CPB management is heavily dependent on broad-spectrum insecticides, thereby stimulating an interest to identify alternative solutions. In this study, we evaluated the efficacy of ledprona, a dsRNA interference-based bioinsecticide, following different application timings and frequencies to reduce CPB populations, minimize defoliation, and protect potato yields across diverse conditions in the northern U.S. RESULTS: Ledprona applied three to five times, starting when overwintered adults were present to a week after initial egg hatch, consistently provided the greatest suppression of first-generation larvae, and significantly reduced potato defoliation and yield loss. Applications initiated when larvae were abundant and most eggs had hatched, followed by one or two applications showed reduced effectiveness. While adult CPB control was inconsistent, ledprona effectively suppressed first-generation larval populations and defoliation, demonstrating its value as an effective novel bioinsecticide. CONCLUSION: Optimal timing and frequency of ledprona applications are critical for effective CPB control in potato. Our findings indicated that the phenology of the CPB infestation will need to be monitored closely early in the season to enable proper timing of the first ledprona application. We offer practical insights for how best to integrate dsRNA-based insecticides into season-long CPB management programs. © 2025 Society of Chemical Industry.

  PublisherOA PDFDOI

• Practical resistance to spinosad in an onion maggot (Diptera: Anthomyiidae) population in New York

  Journal of Economic Entomology · 2025-02-21 · 1 citations

  articleSenior author

  Onion maggot, Delia antiqua (Meigen), is a significant constraint on onion production across the temperate regions of North America. Early season infestations can reduce plant stands up to 75% if untreated. Effective management of D. antiqua has historically relied on insecticide seed treatments, with spinosad being among the most commonly used options. However, declining control efficacy observed on a New York onion farm over several years raised concerns about the potential development of insecticide resistance. The purpose of this research was to (i) evaluate the efficacy of spinosad seed treatment in managing D. antiqua in the affected field from 2021 to 2024 and (ii) to assess the population's susceptibility to spinosad using a laboratory bioassay. Results from field trials revealed that the percentage of control of D. antiqua using spinosad seed treatment relative to a noninsecticide treatment declined from 51% in 2021 to -83% in 2024. Laboratory bioassay results showed an increase in LC50 values from insects collected from nontreated and spinosad-treated plants in 2023. These results document the first case of reduction in spinosad seed treatment efficacy in D. antiqua that has practical consequences for pest control (practical resistance). Given the critical role of spinosad seed treatment in onion maggot management, these results underscore the need for evaluating resistance prevalence in other populations across North America.

  PublisherDOI

• Rearing of <i>Spissistilus festinus</i> [Say, 1830] (Hemiptera: Membracidae) on snap bean to facilitate studies on the transmission biology of grapevine red blotch virus

  Journal of Economic Entomology · 2025-07-11 · 1 citations

  articleOpen access

  Spissistilus festinus [Say, 1830] (Hemiptera: Membracidae) is a well-known pest of leguminous crops and a more recently described pest of grapevine due to its ability to transmit grapevine red blotch virus, an economic threat to grape production. Legumes (family Fabaceae), unlike grapevines (Vitis vinifera L.), are preferred feeding and reproductive hosts for S. festinus. Here, we analyzed the development and behavior of S. festinus on snap beans (Phaseolus vulgaris) in comparison to alfalfa (Medicago sativa) and grapevines, with an emphasis on colony establishment and population growth. Snap beans supported all stages of S. festinus development, promoting feeding, reproduction, and colony establishment, as well as supporting a faster life cycle, particularly on detached trifoliates in controlled environmental chambers, compared with alfalfa. Moreso, social aggregation of S. festinus adults was observed on snap bean plants with the petiole as a preferred feeding site. A preference toward grapevine petioles was also seen, though their survival and aggregation behaviors drastically declined on this nonlegume host. Dissecting the alimentary canal of S. festinus revealed more orange, refractive oil droplets, and air bubbles in specimens from grapevine compared to specimens from snap bean or alfalfa, suggesting possible disruptions in digestive processing or nutritional deficiencies with the former host. Together, our findings highlight snap bean as an ideal host for rearing populations of S. festinus to be used in grapevine red blotch virus transmission studies.

  PublisherOA PDFDOI

• Colorado potato beetle management in potato in New York, 2024

  Arthropod management tests · 2025-01-01

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Trap design and pheromone lure type influence <i>Helicoverpa zea</i> (Lepidoptera: Noctuidae) moth capture in sweet corn

  Journal of Economic Entomology · 2025-07-15 · 4 citations

  articleSenior author

  Corn earworm, Helicoverpa zea Boddie, is a highly destructive pest of sweet corn, Zea mays L. convar. saccharata Koern, because of larval feeding. Insecticides are used to manage this pest, and application frequency typically depends on H. zea abundance in the field. Pheromone-baited traps are used to estimate H. zea abundance, but differences in trap designs and lure types likely impact moth capture. This study comprehensively evaluated the influence of currently available traps, pheromone lures, and their combinations on H. zea moth captures across the eastern United States in 2022 and 2023. Moth capture was evaluated using combinations of the Hartstack, Heliothis, and green bucket traps with the Hercon (87% (Z)-11-hexadecenal, 8% (n)-hexadecanal, 3% (Z)-9-hexadecenal, and 2% (Z)-7-hexadecenal), Scentry, Trécé, and Alpha Scents (all 3 lures contained 97% (Z)-11-hexadecenal and 3% (Z)-9-hexadecenal) pheromone lures. Additionally, moth capture was evaluated using a modified Hartstack trap, which had the same bottom opening size as the Heliothis trap. Results demonstrated that the Hartstack trap captured significantly more moths than the Heliothis trap, but the modified Hartstack captured similar numbers of moths as the Heliothis trap, suggesting that the Hartstack's larger trap opening may increase moth capture compared with the modified Hartstack. The Hercon lure attracted significantly more moths than the Trécé and Alpha Scents lures, but attracted a similar number of moths as the Scentry lure. These findings are valuable for improving H. zea moth capture and will inform future studies that refine insecticide application frequency guidelines based on moth capture rates.

  PublisherDOI

• Performance of novel alternatives to neonicotinoid insecticide seed treatments for managing maggots (Diptera: Anthomyiidae) in large-seeded vegetable crops

  Crop Protection · 2025-08-05 · 3 citations

  articleSenior author
  PublisherDOI

• Optimizing spirotetramat applications for effective onion thrips control in bulb and green onions

  Journal of Economic Entomology · 2025-06-26

  article

  Onion thrips, Thrips tabaci Lindeman, (Thysanoptera: Thripidae) is the most significant pest of Alliums (Amaryllidaceae) and is primarily managed with insecticides. Spirotetramat, a systemic insecticide, is currently recommended for early season use in bulb onion production, but its residual effects based on application timing, frequency, and plant age are poorly understood. From 2016 to 2023, we conducted a series of trials assessing the impact of these factors on thrips control. We compared 2 application timings and frequencies on onion thrips management in bulb onions. Finally, we conducted a separate green onion experiment, altering plant age and application frequency to determine the effect on onion thrips populations and spirotetramat uptake by the plant. Our results showed that 2 sequential applications of spirotetramat reduced onion thrips densities by 50%, but application timing had no impact on thrips densities in both bulb and green onions. Green onions that received 2 applications of spirotetramat had significantly higher spirotetramat levels in the leaf tissue than those treated once. In green onions, more spirotetramat was detected in young plants compared with older ones, and there was a negative correlation between spirotetramat levels in leaf tissue and onion thrips densities on plants. Overall, our results indicated that 2 applications of spirotetramat are necessary for effective onion thrips control on bulb onion and green onion, likely due to increased insecticide levels in plant tissue.

  PublisherDOI

Frequent coauthors

• Anthony M. Shelton

  85 shared

• John Speese

  73 shared

• Marc Fuchs

  30 shared

• George G. Kennedy

  24 shared

• J. Plate

  New York State Department of Agriculture and Markets

  23 shared

• Fred R. Musser

  Mississippi State University

  22 shared

• Jessica D. Petersen

  Minnesota Department of Natural Resources

  21 shared

• E. Larentzaki

  New York State Department of Agriculture and Markets

  20 shared

Labs

• Entomology Department, Cornell UniversityPI

Education

• PhD, Entomology

  NC State University

  1994