MEMORANDUM 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

MAY 15 2013 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile for Registration Review: Pymetrozine (PC Code 101103) 

FROM: Nikhil Mallampalli, Entomologist u/q ,.; fVt~ Biological Analysis Branch /It k ~ 

THRU: 

TO: 

Jihad 

Science 

Alsadek, 

Information 

Economist 

and Analysis 

.,f~ Branch ~~ 

Stephen Smearman, Economist },_ ..J .. _ 1 _. . -· _ 

Biological 

Economic Analysis 

and Economic 

Branch 

Analysis 

~ 

Division 

~ 

(7503P) 

Arnet Jones, Chief 

Biological Analysis Branch 

Diann Sims, Chief ;<{] .· 1 '-'J"--"' 

Science Information and Analysis Branch 

Timothy Kiely, Chief a VV\J:;Q. Economic Analysis Branch! 

Biological and Economic Anal is Division (75 3P) 

Steven Snyderman, Chemical Review Manager 

Risk Management and Implementation Branch 3 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel date: November 14,2012 

Revised May 3, 2013 

INTRODUCTION 

The purpose of this document is to convey usage information and a broad overview of the pest 

management roles of pesticides that are beginning to undergo registration review. The 

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anticipated audience consists of the team of EPA staff currently evaluating the registration status 

of pymetrozine and eventually the general public. This document builds upon the data already 

provided in the "usage and label use data packages" that are also provided to Registration 

Review teams by BEAD. The document is based on information and data available to BEAD as 

of March 2013. 

Pymetrozine was first registered in the U.S. in 1999 (EPA 2000). This is the first registration 

review of this insecticide. It is marketed by Syngenta under two products: Fulfill® and 

Endeavor® . The Insecticide Resistance Action Committee classifies pymetrozine as a member of 

the Mode of Action (MOA) Group 9, subgroup B (IRAC 2012). This group of insecticides acts 

through nerve action to block feeding behavior, mainly in insects in the order Homoptera 

(includes aphids, whiteflies, and leafhoppers, which are often major agricultural pests and 

vectors of plant diseases). These are the only insects listed as being controlled on pymetrozine 

labels. While pymetrozine is most effective in suppressing feeding (and subsequently causing 

mortality) in these insects, BEAD located a few research articles indicating neurological impacts 

in other insects, such as locusts. These studies are briefly described in the "Biological Aspects" 

section below. Details of pymetrozine nervous system action have not been fully elucidated, but 

it is thought to work by affecting serotonin in the insect nervous system (Chang and Snyder 

2008). The only other commercially available insecticide included in the same MOA is 

flonicamid. 

IDSTORY OF BEAD ASSESSMENTS FOR PYMETROZINE 

BEAD did not find any assessments specifically for pymetrozine in the BEAD Official Records. 

Of the documents that included pymetrozine that were found, all of them were relatively old and 

the most recent dated from 2009. 

BEAD did not find any Section 18 (emergency exemption) requests for pymetrozine submitted 

to BEAD for analysis in the last 5 years. However, there were 10 such requests between the 

years 1998 and 2001 in the OPP Section 18 database for potatoes, pecans, lettuce and hops (see 

http://cfpubl.epa.gov/oppref/section18/search.cfin). One request (for pecans) was issued in 2000 

for control of aphids in Georgia. Two more Section 18s from Washington and Idaho went crisis 

for control of aphids in hops in 2003. 

COMMON FORMULATIONS AND APPLICATION METHODS 

Pymetrozine is formulated only as water dispersible granules. Application methods include 

tractor mounted spray equipment, chemigation, aerial equipments, and handheld equipments. 

USE SITES 

Agricultural Use Sites 

Pymetrozine is registered for use on many crops, including widely planted such as lettuce and 

potatoes, and minor specialty crops such as nut trees, potatoes, turmeric, melons, gourds, 

cucurbits, cotton, chayote, vegetables, asparagus, celery, mustard spinach, and fruit trees. 

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Non-Agricultural Use Sites 

Pyrnetrozine is registered for use on Christmas tree plantations, outdoor ornamentals and 

greenhouse crops. 

USAGE 

Figure 1 (below) shows the use ofpyrnetrozine in pounds active ingredient (a.i.) for the time 

period of2000-2011. The use is increasing during this time period. This is represented by an 

annual average of 9,000 pounds active ingredient (lbs. a.i.) used to treat an annual average of 

106,000 acres, for an overall average application rate of 0.1 lb. a.i. per acre during this time 

period. 

Figure 1. Agricultural Usage Data for Pymetrozine in Pounds A.I. (2000-2011). 

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Source: Proprietary Data, 2000 -2011. 

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Page 3 of9 

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Cantaloupes 

- Lettuce 

--.-Pecans 

Potatoes 

From 2007-2011, the annual total agricultural usage averaged approximately 10,000 pounds 

active ingredient (lbs. a.i.) for 116,000 treated acres with an overall average application rate of 

0.1 lbs. a.i. per acre. 

During this time frame, the crops with the most use in terms of total pounds of pymetrozine 

active ingredient used, total area treated, and crop application rate are potatoes, pecans, lettuce, 

and cantaloupes, as shown in Table 1. The states with the most agricultural usage in terms of 

pymetrozine pounds active ingredient applied, total area treated, and state application rate are 

California, Georgia, Florida, Colorado, and Montana, as described in Table 2. 

Table 1. Percent of Pymetrozine used on Top Crops in Terms of Total Pounds (a.i.), and 

Total Area Treated, 2007-2011 

Crop %of Total Pounds A.I. %of Total Area Treated 

Potatoes 41 39 

Pecans 16 15 

Lettuce 12 13 

Cantaloupes 6 6 

Source: EPA Propnetary Data, 2007-2011. 

Table 2. Percent of Pymetrozine used in States in Terms of Total Pounds (a.i.) and Total 

Area Treated, 2007-2011 

Crop %of Total Pounds A.l. % ofTotal Area Treated 

California 26 28 

Georgia 16 16 

Florida 11 12 

Colorado 11 7 

Montana 7 8 

Source: EPA Propnetary Data, 2007-2011. 

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Agricultural Usage by Crop Reporting District 

Another measure of usage is the use intensity. In this analysis, the use intensity is expressed as 

the pounds a.i. applied per 1,000 acres of land in farms. This differs from the application rate, 

which is expressed as the pounds a.i. applied per treated area. An average application rate of 0.1 

lbs a.i. per acre is equivalent to 100 lbs a.i. per 1000 treated acres. In contrast, the maximum use 

intensity ranges from 0.41-1.02lbs. a.i. per 1,000 acres of farm land. Figure 3 spatially 

represents pymetrozine use intensity in potatoes in the northern part of Maine in the USA. 

Figure 3. Pymetrozine Usage by Crop Reporting District (2006- 2010) 

Average Pounds Per 

1,000 Acres of Farmland 

- <0.05 

0.05-0.10 

0 0.11-0.21 

0. 22- 0.40 

0.41- 1.02 

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This is a map of agricultural pesticide usage at the Crop Reporting District (CRD) level 

prepared by BEAD for use in the Environmental Fate and Effects Division documents. 

These maps are used to help visualize where the pesticide being considered is most likely 

to be used and can be helpful in scenario selection and placing the exposure assessment in 

context. CRDs are boundaries created by USDA NASS which are aggregates of counties 

(USDA, 2010). Pesticide usage is displayed as average pounds (for the years 2006-2010) 

per 1,000 acres of farmland in a CRD to normalize for the variation in farmland between 

CRDs. Farmland acreage was obtained from USDA (2007). Farmland or "land in farms" 

is defined by USDA as follows: 

The acreage designated as "land in farms" consists primarily of 

agricultural land used for crops, pasture, or grazing. It also 

includes woodland and wasteland not actually under cultivation or 

used for pasture or grazing, provided it was part of the farm 

operator's total operation. Large acreages of woodland or 

wasteland held for nonagricultural purposes were deleted from 

individual reports during the edit process. Land in farms includes 

CRP, WRP, FWP, and CREP acres. Land in farms is an operating 

unit concept and includes land owned and operated as well as land 

rented from others. Land used rent free was reported as land rented 

from others. All grazing land, except land used under government 

permits on a per-head basis, was included as "land in farms" 

provided it was part of a farm or ranch. Land under the exclusive 

use of a grazing association was reported by the grazing 

association and included as land in farms. All land in American 

Indian reservations used for growing crops, grazing livestock, or 

the potential of grazing livestock was included as land in farms. 

Land in reservations not reported by reservation, individual 

American Indians or non-Native Americans was reported in the 

name of the cooperative group that used the land. In many 

instances, an entire American Indian reservation was reported as 

one farm (2007 Census of Agriculture, USDA). 

Usage is based on private market surveys of pesticide use in agriculture (Proprietary Data, 

2006-201 0). The survey data are limited to the states that represent the top 80-90% of acreage 

for the individual crops; therefore, use may be occurring in regions outside the scope of the 

survey. CRDs showing no usage of pesticides may be due to either the lack of pesticide use in 

the region or non-participation in the agricultural surveys. In addition, across the years, there 

may be variations in the specific crops included in the CRD survey. This may result in a lower 

annual average for the CRD. 

Figure 3 displays ratio data (i.e., average pounds per 1,000 acres of farmland) summarized at a 

very high-level. Readers are strongly cautioned against trying to over interpret the map 

without examination of the underlying data. The underlying data may explain some of the 

many reasons that a Crop Reporting District may have a high value for a particular active 

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ingredient such as significant acreage (compared with the CRD as a whole) of a crop or crops 

with a high application rate and frequency of application. 

The reader should pay particular attention to the figure legends and realize that a map 

prepared for a particular chemical is not directly comparable to a map prepared for a different 

chemical. Scale and units of measurement do matter and may be different between maps. 

The geographical depiction of pymetrozine use indicates that the highest use of this 

insecticide (orange or red shading) occurs in the coastal, central, and southern regions of 

California, Arizona, in parts of the southeastern U.S. and Maine (Figure 3). This suggests that 

pymetrozine use is relatively high in crops such as tree fruits and vegetables (widely grown in 

the relevant regions of California and Arizona, and also comparatively high in potatoes, a 

major crop in Maine. 

Non-Agricultural Use Sites 

In 2002, 2004, and 2006, the most recent years for which non-agricultural data are available, less 

than 500 lbs. a.i. ofpymetrozine were used in the nursery/greenhouse sector. (Kline, and Co., 

Inc., 2002, 2004, and 2006) 

BIOLOGICAL ASPECTS RELEVANT TO PYMETROZINE 

Resistance to pymetrozine has been reported for two species of whitefly, but no aphid or 

leafhopper pests appears to have developed resistance as yet, according to a publicly accessible, 

large database of published scientific literature on arthropod resistance that is maintained by 

Michigan State University (available at http://www.pesticideresistance.com/index.php). 

According to the database, in 1994 resistance was documented in Spanish populations of the 

sweet potato whitefly, Bemisia tabaci. In 2008 and 2009, resistance developed in populations of 

the greenhouse whitefly, Trialeurodes vaporarium, in China, Germany, and Spain. No reports 

were found for whitefly populations in the U.S. 

Pymetrozine has some unusual attributes that may make it a valuable option for crop growers 

interested in managing Homopteran pests with integrated pest management (IPM) principles in 

mind. It has translaminar systemic activity, and is thus available to pests through plant sap as 

well as direct contact (Harrewijn and Kayser 1997). Some studies have reported that 

pymetrozine has little to no harmful impact on natural enemies of pests such as parasitic wasps 

(e.g., Liu eta/. 2012; see references in Harrewijn and Kayser 1994 and Chang and Snyder 

2008). 

Interestingly, at least one study found that pymetrozine had the unexpected benefit of causing a 

non-target pest, the Colorado potato beetle, to leave treated potato plants (Chang and Snyder 

2008). BEAD also located one study that found some effects of pymetrozine on locusts 

(Kaufman et al. 2004). The authors injected pymetrozine into the grasshopper Locusta 

migratoria and found that it caused them to extend their hindlegs for considerable lengths of 

time. This effect was not seen in sap-sucking insects such as aphids. Feeding immature locusts 

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pymetrozine treated wheat inhibited food intake and reduced weight gain; however, this effect 

was reversible. The larger implications of this laboratory study remain unclear. 

DATA NEEDS RELEVANT TO BEAD'S FUTURE WORK ON PYMETROZINE 

Obtaining additional information on the following items would improve BEAD's assessment of 

the importance of pymetrozine as a pest management tool. This assessment is likely to be 

required as part of the registration review of this pesticide. 

1. For non-agricultural uses, information on target pests and treatment costs. 

2. Recent resistance reports for pymetrozine in populations of important target pests. 

3. For all uses, recent comparative efficacy data for pymetrozine vs. likely alternatives for 

major target pests. 

REFERENCES: 

Chang, G. C. and W.E. Snyder. 2008. Pymetrozine causes a nontarget pest, the Colorado Potato 

Beetle (Coleoptera: Chrysomelidae), to leave potato plants. J. Econ. Entomol. 101(1): 74-

80. 

EPA. 2000. Pesticide Fact Sheet: Pymetrozine. Available on the web at 

http://nepis.epa.gov/ Adobe/PDF /P 1 OOBIBS.PDF. 

EPA Proprietary Data, 2000-2011. 

Harrewijn, P. and H. Kayser. 1997. Pymetrozine, a fast acting and selective inhibitor of aphid 

feeding. In situ studies with electronic monitoring of feeding behavior. Pestic. Sci. 49: 

130-140. 

Kaufman, L., Schurmann, M. Yiallourosa, P.Harrewijn, H. Kayser. 2004. The serotonergic 

system is involved in feeding inhibition by pymetrozine. Comparative studies on a locust 

(Locusta migratoria) and an aphid (Myzus persicae). Comparative Biochemistry and 

Physiology, Part C 138 (2004) 469--483 . 

Kline and Co., Inc. 2002, 2004, and 2006. 

Krupke, C.H., G. Hunt, and R.E. Foster. 2012. Protecting Honeybees from Pesticides. 

Publication E-53W of the Purdue University Extension Service. Available on the web at: 

http://extension.entm.purdue.edu/publications/E-53.pdf. 

Liu, T-X, Y-M Zhang, L-N Peng, P. Rojas, and J.T. Trumble. 2012. Risk assessment of selected 

insecticides on Tamarixia triozae (Hymenoptera: Eulophidae), a parasitoid of Bactericera 

cockerelli (Hemiptera: Trizoidae). J. Econ. Entomol. 105(2): 490-496. 

USDA, 2006-2010. NASS Crop Reporting Districts. 

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http://www.ers.usda.gov/briefing/anns/resourceregions/resourceregions.htm#nass. 

USDA, 2007. Census of Agriculture. 

http://www.agcensus.usda.gov/Publications/2007/index.asp. 

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