United States Department of Agriculture

June 15, 2020

Elissa Reaves, Ph.D., Acting Director Re-Evaluation Division (7508P) Office of Pesticide Programs, Environmental Protection Agency 1200 Pennsylvania Ave., N.W. Washington, DC 20460-0001

Re: USDA Comments on the Draft Human Health and Ecological Risk Assessments for Novaluron for Registration Review; EPA-HQ-OPP-2015-0171.

Dear Dr. Reaves:

Thank you for the opportunity to comment on EPA’s draft human health and ecological risk assessments for novaluron, posted on May 4, 2020 in the Federal Register. Novaluron is a benzoylurea biosynthesis inhibiting insect growth regulator (IGR), classified by the Resistance Action Committee (IRAC) as a Group 15 insecticide (IRAC, 2020). Novaluron is a selective insecticide that acts primarily on immature insect stages via inhibition of growth and molting. Novaluron is registered and used on a wide variety of agricultural crops including cotton, peanuts, sugarcane, tree fruits, berries, vegetables, and other specialty crops. It is also used in animal agriculture, food-handling establishments, residential and commercial buildings and structures, and as a mosquito larvicide for protection of public health.

Due to novaluron’s relatively narrow-spectrum IGR mode of action, targeting mainly immature insect stages, it has a valuable fit in integrated management (IPM) programs. It is widely noted as being safe to adult stages of predatory mites and beneficial insects, although larval can be observed. It is a particularly important tool for control of Lygus plant bugs in cotton and strawberries, as well as for a variety of lepidopteran pests in tree fruits, berries, potatoes, peanuts, and sugarcane. Its selectivity and relatively long residual activity make it an attractive IPM tool for numerous pest scenarios. As an IRAC Group 15 insecticide, novaluron serves as a key option for chemical rotation programs for management of insecticide resistance.

Novaluron contributes significantly to a novel, diverse, integrated, and complementary reduced- risk insecticide toolbox that has gained broad grower adoption in recent decades. Availability of these tools has allowed for widespread displacement of organophosphate and carbamate insecticide usage in agriculture on multiple crops, particularly for targeting lepidopteran pests. For apples and pears, novaluron has good against pests such as codling moth and other leafroller species (WSU, 2020). It is also rated as having moderate efficacy against pear psylla nymphs in low-pressure situations (OSU, 2020), which is a notoriously difficult pest to manage due to widespread insecticide resistance development. Novaluron is also commonly recommended in cranberries for lepidopteran pests such as fireworms, spanworms, and tipworms (Armstrong, 2016).

In sugarcane, novaluron is effective against borer pests such as sugarcane borer and corn stalk borer (Beuzelin, et al., 2019), which are linchpin sugarcane pests that were historically managed with organophosphate and other broad-spectrum . In potatoes, novaluron can be used

Office of Pest Management Policy 1400 Independence Avenue, S.W. Washington, D.C. 20250-0314 USDA is an Equal Opportunity Provider and Employer to control potato tuberworms and other caterpillar pests (UC-IPM, 2019) and larvae of Colorado potato beetles (UMass, 2013), which is a textbook pest case for resistance management challenges in IPM. For peanuts, novaluron is recommended for controlling thrips and multiple lepidopteran pests such as armyworms, loopers, and velvetbean caterpillars (AAMU and Auburn, 2019). Novaluron also has additional benefits for control of miscellaneous lepidopteran pests across other vegetables including cucurbits, fruiting vegetables, and Brassicas.

Our detailed comments are attached for your review. USDA stands ready to provide EPA with additional information on the benefits of novaluron, as well as additional characterization information to help address and/or refine EPA’s risk estimates, if needed. Please let me know if you would like to discuss further.

Sincerely,

Sheryl H. Kunickis, Ph.D. Director

Page 2 of 6 Ecological Risk Assessment

EPA’s ecological risk assessment for novaluron presented some helpful risk characterization information on the relatively few identified risks of potential concern. USDA appreciates EPA’s streamlined approach to the novaluron ecological risk assessment, which focused on the most germane risks of concern identified from prior assessments. This orients the assessment to the most likely potential exposure scenarios of concern. We note that even under screening-level exposure assumptions, novaluron is unlikely to pose any risks of concern to fish, aquatic phase amphibians, adult bees, or non-target plants, and poses no acute risks to birds or mammals. This overall ecological risk profile makes novaluron a relatively low-risk option for insect pest management on a variety of crops.

Aquatic Invertebrates

Like many insecticides, it is not surprising that novaluron would show some likelihood of risks to aquatic invertebrates, particularly benthic organisms, given novaluron’s high binding affinity to organic matter. This is particularly true for exposures driven by direct applications to water, which are made to control larval stages of mosquitoes for protection of public health and for which exposure was assessed at the limit of solubility. Novaluron also has some benefits for uses on cranberries, where in-field (flooding) estimates for aquatic invertebrate exposure include applications targeting lepidopteran pests on the crop itself. While risk concerns for aquatic invertebrates are notable, for estuarine/marine taxa, EPA’s exposure models for agricultural applications may significantly over-estimate concentrations that result from movement off-field to brackish/saltwater habitats. Use of the farm pond scenario for exposure estimation makes it difficult to quantify real-world exposure for the majority of agricultural fields that are not directly adjacent to marine habitat and for which residues would be subject to considerable downstream dilution. USDA also notes that several mosquito larvicide labels specify that applications are “to sites which do not drain into natural water bodies” or “which do not drain directly into natural water bodies.”

As EPA develops a risk management strategy for these and other potential risks of concern, USDA requests that risk managers recognize and consider the comparative risks of likely insecticide alternatives in agriculture. We suggest that EPA risk managers might consider practical advisory mitigation to reduce the potential for drift away from the application site. Since novaluron acts as a contact insecticide and kills via both contact and ingestion, without significant systemic activity in plants, thorough crop coverage on leaves and fruit is critical to achieving adequate efficacy. Particularly for airblast applications on tree fruits and for ground- boom applications to cotton, peanuts, strawberries, and other vegetables, coverage of the under- sides of leaves is critically important for reaching egg and young larval life stages in challenging locations. For pests such as Lygus, direct contact with the insect is also difficult. Advisory drift language or language mandating nozzles and pressure settings to deliver “fine and coarser” droplet sizes would likely help reduce the potential for problematic off-field exposures via drift while maintaining practical utility and efficacy for growers. However, USDA is concerned that if stringent droplet size restrictions are applied to novaluron, it would likely drive some growers to either use alternatives with higher relative risks, or to increase application rates of novaluron in

Page 3 of 6 order to compensate for decreased efficacy. Either of these outcomes would run counter to EPA’s overall risk reduction goals.

Birds and Mammals (Chronic Only)

USDA appreciates EPA’s characterizations around potential chronic exposure concerns for mammals. Given that risk concerns are not observed under mean Kenaga exposure assumptions, we agree with EPA’s conclusion that chronic risks are not likely for mammals. We note that similar characterizations also accordingly reduce the magnitude of LOC exceedances modeled for birds. We further suggest that assumptions about bird foraging may also potentially over- estimate real world exposure likelihood over a relevant time frame that corresponds to test study conditions driving chronic effects. We request that EPA risk managers consider practical advisory mitigation to reduce the potential for drift away from the application sites, as discussed above.

Terrestrial Invertebrates (Bees)

Given novaluron’s mode of action, USDA agrees with EPA in recognizing the potential for risks of concern to bee larvae, which are not surprising. We also recognize that there is a data gap for assessing chronic risks to adult bees, but we agree with EPA’s characterization that these risks are unlikely given novaluron’s mode of action. For larval exposure, we suggest that the lack of systemic activity for this active ingredient makes significant movement of novaluron into nectar or pollen unlikely, other than via direct contact from spraying of blooms themselves. While growers are generally judicious about avoiding pesticide applications to bee-pollinated crops during bloom, certain pest outbreaks sometimes necessitate such treatments, particularly for crops such as cotton or strawberries where bloom is indeterminate and Lygus bugs are a major pest of concern. Considering the universe of available insecticide alternatives, including organophosphates, carbamates, synthetic , and neonicotinoids, all of which pose acute risks to bees, USDA suggests that novaluron presents a relatively lower-risk option for such applications. We request that EPA risk managers consider the overall ecological risk profile of novaluron within the larger context of comparative risk estimates for the most likely insecticide alternatives for characterizing pollinator risks. Given the lack of acute risk to adult bees, the uncertainty regarding actual larval exposure estimates, and the resistance management benefits of this chemical, USDA suggests that bloom restrictions on applications of novaluron are not warranted as it could drive growers to use alternative insecticides with comparatively worse risk profiles.

Human Health Risk Assessment

USDA supports EPA’s draft human health risk assessment and notes that all dietary, aggregate, and spray drift risk estimates for novaluron are below levels of concern. While EPA identified a potential risk of concern for mixers, loaders, and applicators using mechanically pressured handguns in poultry/livestock housing and feed lots, USDA notes that that this risk would be adequately addressed by requiring a PF-10 respirator.

Page 4 of 6 International MRL Harmonization

USDA recognizes the increasing importance of international maximum residue limit (MRL) harmonization efforts and appreciates that EPA evaluated the potential for raising several existing novaluron tolerances in order to harmonize with Codex. USDA believes that there may be further potential to harmonize with Codex for dried apple pomace and meat from mammals, as the Codex MRLs established for these commodities are higher than corresponding U.S. tolerances (Codex Alimentarius, 2011). In the case of apple pomace, EPA has established a tolerance for the commodity in its wet form, however, establishing a tolerance for the dried form may provide additional clarity for the purposes of trade and MRL enforcement. We also note that Codex has established a single stone fruit crop group MRL at 7 ppm, while EPA has established three separate tolerances for the cherry subgroup at 8 ppm, the peach subgroup at 1.9 ppm, and the plum subgroup at 1.9 ppm. USDA encourages EPA to evaluate the potential for a stone fruit group tolerance at 8 ppm, or to consider raising the peach and plum subgroup tolerances to 7 ppm in order to align with Codex. From the available residue chemistry documentation (DP357060, 9/9/2009), it appears that the median residues from the cherry, peach, and plum datasets are close to falling within the “five times range” typically utilized for the establishment of group tolerances. Furthermore, given that dietary risk estimates for novaluron are well below levels of concern, even under conservative exposure assumptions (e.g., tolerance-level residues, ½ limit of quantification (LOQ) residues for all commodities not covered by higher tolerances), USDA suggests that further action to harmonize with Codex is unlikely to impact EPA’s dietary or aggregate safety findings.

EPA’s risk assessment notes that, “for the remaining commodities, harmonization with Codex and/or Canada is not recommended as the difference between the tolerances and MRLs is too large.” In general, USDA suggests that the instances where MRL differences are large are, in fact, those which have the highest potential to impact trade. Consequently, USDA encourages EPA risk assessors to evaluate the potential for Codex MRL harmonization to the greatest extent possible (i.e., include all harmonization options in the assessment of dietary and aggregate risk), which would then allow risk managers to consider the feasibility and practical implications of modifying U.S. tolerances for the purpose of harmonization and trade facilitation.

Page 5 of 6 References

Alabama A&M University (AAMU) and Auburn University, 2019. Peanut insect control recommendations, AAMU and AU Extension Publication IPM-0360. https://www.aces.edu/wp-content/uploads/2019/10/IPM-0360-Peanuts2020_012820L- G.pdf. Accessed May 27, 2020.

Armstrong, C., 2016. Integrated pest management in cranberries: an overview. University of Maine, published extension presentation. https://extension.umaine.edu/cranberries/wp- content/uploads/sites/40/2020/04/Cranberry-IPM-Overview-opt.pdf. Accessed May 27, 2020.

Beuzelin, J., Cherry, R., Nuessly, G., and Sandhu, H., 2019 (updated). Insect Management in Sugarcane. University of Florida IFAS Extension publication. https://edis.ifas.ufl.edu/pdffiles/IG/IG06500.pdf. Accessed May 27, 2020.

Codex Alimentarius, 2011. Pesticide Database: 217 - Novaluron. http://www.fao.org/fao-who- codexalimentarius/codex-texts/dbs/pestres/pesticide-detail/en/?p_id=217. Accessed May 27, 2020.

IRAC, 2020. Insecticide Resistance Action Committee Mode of Action Classification, online module, updated 2020. https://www.irac-online.org/modes-of-action/. Accessed May 27, 2020.

Oregon State University (OSU), 2020. Pest Management Guide for Tree Fruits. Oregon State University Extension Service. https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em8203.pdf. Accessed May 27, 2020.

UC-IPM, 2019. Potato Tuberworm, Potato Pest Management Guidelines. University of California Statewide Integrated Pest Management Program. https://www2.ipm.ucanr.edu/agriculture/potato/Potato-Tuberworm/. Accessed May 27, 2020.

University of Massachusetts (UMass), 2013. Colorado potato beetle, management. UMass Extension publication. https://ag.umass.edu/vegetable/fact-sheets/colorado-potato-beetle- management. Accessed May 27, 2020.

Washington State University (WSU), 2020. 2020 Crop Protection Guide for Tree Fruits in Washington. http://cpg.treefruit.wsu.edu/. Accessed May 27, 2020.

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