Docket Number EPA-HQ-OPP-2013-0539 

www.regulations.gov 

-

Dried Fermentation Solids and Solubles of 

Myrothecium verrucaria 

Final Work Plan 

(PC Code: 119204) 

Registration Review 

Case Number 6051 

September 2014 

Approved by: 

Robert McNally, Director 

Biopesticides and Pollution 

Prevention Division 

Date: 
INTRODUCTION 

This is the U.S. Environmental Protection Agency's (EPA) Final Work Plan (FWP) for the 

Registration Review of Dried Fermentation Solids and Solubles of Myrothecium verrucaria. This 

FWP follows the Preliminary Work Plan (PWP) posted in the Registration Review docket for 

Dried Fermentation Solids and Solubles of Myrothecium verrucaria (EPA-HQ-OPP-2013-0539). 

Dried Fermentation Solids and Solubles of Myrothecium verrucaria is registered for applications 

to soil in agricultural fields and ornamental crops to control nematodes that parasitize plants, 

usually through the roots, thereby reducing the quality and yield of the plants they infest. 

The EPA is implementing the Registration Review program pursuant to Section 3(g) ofthe 

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and will review each registered 

pesticide every 15 years to determine whether it continues to meet the FIFRA standard for 

registration. Changes in science, public policy, and pesticide use practices occur over time. The 

Registration Review program is intended to make sure that, as the ability to assess risk evolves 

and as policies and practices change, all registered pesticides continue to meet the statutory 

standard of no unreasonable adverse effects to human health or the environment. The public 

phase of Registration Review begins when the initial docket is opened for each case. Information 

on this program is provided on the EPA's website. 1 

The FWP begins with any updates since the PWP was issued. Next, it provides a summary of 

substantive comments received, if any, during the public comment period for the PWP 

concerning anticipated data needs, expected risk assessments, or the estimated timeline identified 

in the PWP, and a summary of the EPA's responses to those comments. This section is followed 

by the planned data needs, risk assessments expected to be conducted, and the projected 

Registration Review timeline for Dried Fermentation Solids and Solubles of Myrothecium 

verrucaria. Lastly, there is a discussion of next steps. 

UPDATES SINCE THE PWP WAS ISSUED 

Over the course of preparing the PWP, EPA became aware that labels for some products 

containing the active ingredient (a.i.), Dried Fermentation Solids and Solubles of Myrothecium 

verrucaria, may have been inconsistent with mitigation measures needed to limit exposure to 

aquatic organisms. According to the ecological risk assessment conducted for the original 

registration in 1996, minimal risk was identified for birds, wild mammals, nontarget plants, 

nontarget insects, and honey bees, but the a.i. was determined to be moderately toxic (LCso = 2.1 

mg/L) to rainbow trout in a 96-hour static renewal study. Data submitted on aquatic invertebrates 

were determined to be unacceptable. However, at that time EPA determined that a conclusion of 

minimal risk to all nontarget organisms could be made as long as: 1) batch-level quality control 

measures were in place to ensure non-viability of the Myrothecium verrucaria fungus and that 

the presence of mycotoxins were below a specified limit, 2) end-use product labels contained 

language prohibiting application to water,2 and 3) application methods were limited to soil1 See http://www.epa.gov/oppsrrdllregistration review! 

2 ENVIRONMENTAL HAZARDS: For terrestrial uses: Do not apply directly to water, or to areas where surface water is present 

or to intertidal areas below the mean high water mark. Do not contaminate water by cleaning of equipment or disposal of 

equipment washwaters. 

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applied spray with incorporation (mechanical means or watering in) or drip chemigation to 

reduce the potential for the a.i. to move beyond farm fields into surrounding streams, ponds, and 

other water bodies. The EPA also concluded that, with these mitigations in place, this 

preparation of Myrothecium verrucaria should pose no threat to endangered species when used 

according to label directions. 

As discussed in the PWP, EPA was able to confirm the mitigation measures described in items 1 

and 2 were in place, but would need to determine whether labels for end-use products containing 

Dried Fermentation Solids and Solubles of Myrothecium verrucaria were consistent with 

restrictions on application methods as described in item 3. Between 2000- 2003, certain labels 

allowed application by border, flood, basin and furrow chemigation. Since the PWP was issued 

in September 2013, the registrant, Valent Biosciences, Inc., agreed to restrict chemigation 

application to only drip chemigation, thereby significantly reducing the likelihood of fish and 

other aquatic species being exposed to the pesticide. In 2014 The EPA accepted label 

amendments for the three end-use products- Ditera WP (EPA Reg. No. 73049-37), Ditera ES 

(73049-43), and Ditera DF (73049-67) - that revised the Directions for Use sections by deleting 

all other forms of chemigation. 

The current labels comport with the recommendations of the original ecological risk assessment, 

and adverse effects to nontarget organisms are not anticipated due to low toxicity, lack of 

exposure to the applied fungus, or both. Myrothecium verrucaria is a common fungus in the 

environment, and is found in plant material, cellulosic matter, running and still water, and in 

various cultivated and non-cultivated soils. Therefore, nontarget organisms in the areas where the 

end-use products would be used likely are naturally exposed to this fungus and its secondary 

compounds. This a.i. is also rendered nonviable, so it will not proliferate in the environment once 

applied. Restricting application methods as required on the current labels is expected to prevent 

exposure in aquatic environments by limiting the amount present on the soil surface and reducing 

the potential for movement off the crop field. This conclusion is supported by research on the 

environmental fate of living pollutant microorganisms in and on soil and their input from land 

into nearby surface waters. While subsurface movement of microorganisms is possible (AbuAshour et al. 1994), surface flow is understood to contribute more to runoff into nearby surface 

waters (Jamieson et al. 2002, see also Collins and Rutherford 2004, Hunter et al. 1992). The 

contribution of subsurface flow can be several orders of magnitude lower than contributions 

from surface flow (e.g., Atwill et al. 2002). Additionally, what is known about movement of 

microorganisms into water is dependent on measurement of viable organisms, and survival in 

soil is important factor determining the presence in nearby surface waters (Jamieson et al. 2002, 

see also Atwill et al. 2002, Collins and Rutherford 2004). Since the a.i. is nonviable, survival and 

reproduction of the a.i. will not occur. Furthermore, common soil microorganisms are expected 

to degrade secondary compounds (Sudakin 2003), and the killed M verrucaria would be subject 

to microbial degradation, as well. 

Based on the above analysis, the recent amendments to the end-use product labels for this 

nonviable fungus are expected to prevent exposure to aquatic organisms, which was the concern 

raised in the original risk assessment. In 2014 a search of the literature was also performed to 

ensure that no additional nontarget effects had been reported that previously had not been 

considered. This search was conducted using multiple databases or collections of databases, 

including lSI Web of Science (includes Science Citation Index Expanded and Current Contents 

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Connect), Agricola, and ProQuest Environmental Science Collection (only peer reviewed articles 

searched, database includes Aqualine, Aquatic Science and Fisheries Abstracts, Bacteriology 

Abstracts, COS Conference Papers Index, Ecology Abstracts, ToxLine, and Toxicology 

Abstracts). The search included all years available in each database, ranging from 1960 to the 

present (2014). Search terms included "Myrothecium verrucaria" in combination with each of 

the following terms: "bird," "mammal," ''fish," "invertebrate," "plant," "insect," "arthropod," 

"arachnid," "reptile," "amphibian," "freshwater," "marine," "aquatic," "toxin," "pathogen," and 

"bee." No reports were found indicating additional effects that were not considered in previous 

risk assessments. Therefore, previous risk assessment conclusions regarding the lack of 

anticipated adverse effects to nontarget organisms, including federally listed threatened and 

endangered species, apply to the current uses of products containing Dried Fermentation Solids 

and Solubles of Myrothecium verrucaria. 

As a result of the label revisions, it is extremely unlikely that residues ofthe pesticide will move 

beyond farm fields into surrounding streams, ponds, and other water bodies, and the risk to 

aquatic species has been practically eliminated. The EPA does not need to revise its ecological 

risk assessment and endangered species assessment from 1996. 

SUMMARY OF COMMENTS AND THE EPA'S RESPONSES 

During the 60-day public comment period on the Dried Fermentation Solids and Solubles of 

Myrothecium verrucaria PWP, which opened on September 25,2013, and closed on November 

25,2013, the EPA received one public comment. The commenter, the FIFRA Endangered 

Species Task Force (FESTF) offered "data developed by FESTF, in response to the Agency's 

endangered species data requirements to address (federally listed endangered] species proximity 

to Myrothecium verrucaria uses." The EPA notes these data in its files; however, the Agency 

does not need to use these data because we no longer plan to conduct an endangered species 

assessment. 

In the PWP, the EPA also solicited comments on the specific topics of environmental justice, 

water quality concerns, and trade irritants, but no comments or information were received on 

those issues. 

PLANNED DATA NEEDS 

The EPA has no anticipated registration review data needs for Dried Fermentation Solids and 

Solubles of Myrothecium verrucaria based on the EPA's risk assessment memoranda and other 

references associated with this pesticidal active ingredient.3 

RISK ASSESSMENTS FOR REGISTRATION REVIEW 

During Registration Review, the EPA will determine whether, pursuant to Section 408(p)(4) of 

the Federal Food, Drug, and Cosmetic Act, Dried Fermentation Solids and Solubles of 

Myrothecium verrucaria qualifies for exemption from the Endocrine Disruptor Screening 

Program (EDSP). The EPA believes that Dried Fermentation Solids and Solubles of 

3 S~e Section 1II ("Bil>li9graph/') of the Dried Fermentation Solids and Solubles of Myrothecium verrucaria PWP. 

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Myrothecium verrucaria is likely not an endocrine disrupter; as such, the EPA may exempt it 

from the EDSP (if exempted, an order will be issued). 

TIME LINE 

The EPA has created the following estimated timeline for the completion of the Registration 

Review for Dried Fermentation Solids and Solubles of Myrothecium verrucaria. 

Registration Review for Dried Fermentation Solids and Solubles of Myrothecium 

verrucaria- Projected Registration Review Timeline 

Activities Estimated MonthlY ear 

Opening the Docket 

Open Docket and 60-day Public Comment Period for Dried September 2013 - Completed 

Fermentation Solids and Solubles of Myrothecium verrucaria 

Close Public Comment Period November 2013 -Completed 

Case Development 

Issue Final Work Plan September 2014- Completed 

Issue Data Call-in N/A 

Data Submission N/A 

Open 30-day Public Comment Period for Draft Risk Assessments N/A 

Close Public Comment Period N/A 

Registration Review Decision 

Open 60-day Public Comment Period for Proposed Registration October 2014 Review Final Decision 

Close Public Comment Period December 20 14 

Registration Review Final Decision and Begin Post-decision 

January 2015 Follow-up 

Total years* 1.5 .. * Th1s schedule IS subject to reviSIOn should unforeseen Issues anse dunng the Reg1stratwn Rev1ew process. In the 

event an issue arises, such as the failure to acquire an EDSP exemption, then an amended FWP will he issued at 

that time. That FWP will identify any newly planned data needs and set forth a new timeline. 

NEXT STEPS 

Due to the label revisions the EPA accepted in 2014, the Agency does not need to conduct new 

risk assessments or issue a data call-in. Ifthe EPA issues an order exempting Dried Fermentation 

Solids and Solubles of Myrothecium verrucaria from the EDSP, then the Agency will open a 60-

day public comment period for the proposed registration review final decision. 

REFERENCES 

Abu-Ashour, J., D. Joy, H. Lee, H. Whiteley, S. Zelin. 1994. Transport of microorganisms 

through soil. Water, Air, and Soil Pollution 75: 141-152. 

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Atwill, E.R, L. Hou, B.M. Karle, T. Harter, K.W. Tate, R.A. Dahlgren. 2002. Transport of 

Cryptosporidium parvum oocysts through vegetated buffer strips and estimated filtration 

efficiency. Applied and Environmental Microbiology 68: 5517-5527. 

Collins R., K. Rutherford. 2004. Modelling bacterial water quality in streams draining pastoral 

land. Water Research 38: 700-712. 

Hunter, C., A. McDonald, K. Beven. 1992. Input of fecal coliform bacteria to an upland stream 

channel in the Yorkshire Dales. Water Resource Research 28: 1869-1876. 

Jamieson, R., R. Gordon, K. Sharples, G. Stratton, A. Madani. 2002. Movement and persistence 

of fecal bacteria in agricultural soils and subsurface drainage water. Canadian Biosystems 

EI)gineering 44: 6.1-6.1 0. 

Sudakin, D.L. 2003. Trichothecenes in the environment: relevance to human health. Toxicology 

Letters 143: 97-107. 

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