UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

JUL .24 2D15 

OFFICE OFCHEMICAL SAFETY 

AND POLLUTION PREVENTION 

:MEMORANDUM 

SUBJECT: Review of Bayer CropScience Benefits Document Supporting the Continued 

Registration of Flubendiamide (Belt SC) (DP# 427644) and BCS White Paper 

(DP# 427994) 

FROM: Colwell A. Cook, Ph. D., Entomologist (!,ir{doj_; 

Biological Analysis Branch 

Donald Atwood, Ph.D., Entomologist i-,}(-1/~ r '1,/+ · 

Science Information and Analysis Brancll'-

Biological and Economic Analysis Division (7503P) 

THRU: Arnet Jones, Chief u vJ... u'\)k.. r m~~ 

Biological Analysis Branch 

TO: 

Diann Sims, Chief /r. p...k. ~:]?; ,J.11A~ Science Information 'ifr!f Ana-?;Cs Branch v v '"" , 

Biological and Economic Analysis Division (7503P) 

Carmen Rodia, Risk Manager Reviewer 

Richard Gebken, Risk Manager 

Deborah McCall, Branch Chief 

Invertebrate and Vertebrate Branch 2 

Registration Division (7504 P) 

Product Review Date: July 1, 2015 

Summary 

Flubendiamide is an insecticide which was conditionally registered in 2008. As part of their 

continued registration Bayer CropScience submitted a Flubendiamide Benefits Analysis 

document (EPA MRID No. 4953300 l ). The registrant used a combination of a private pesticide 

market survey of growers, Arthropod Management Tests, trade journal articles, university 
extension IPM websites, and expert opinions to support claims of the benefits of flubendiamide. 

In general, BEAD uses the same sources to conduct pesticide benefits assessments, and agrees 

with the registrant's findings. BEAD agrees with Bayer CropScience findings that 

flubendiamide plays a role in integrated pest management and insecticide resistance management 

based upon the following characteristics: specificity to Lepidopteran larvae; non-systemic but 

translaminar properties; and no to low impacts on beneficial arthropods. Bayer CropScience has 

determined that the main alternatives to flubendiamide will be synthetic pyrethroids. BEAD 

found that in crops such as alfalfa and soybeans, synthetic pyrethroids are the most used 

insecticides and growers will likely use them if flubendiamide were not available for use. But 

for other crops, such as almonds and peppers, growers are using other pesticides like 

methoxyfenozide and chlorantraniliprole, and these are the most likely replacements for 

flubendiamide. BEAD is unable to determine if multiple applications of the alternatives are 

required to control the primary target pests, as comparative product performance analyses were 

not conducted for this review. 

Review of Bayer CropScience Benefits Analysis 

Bayer CropScience (BCS) submitted a document (EPA MRID No. 49533001) to support their 

claim that flubendiamide is valuable both in integrated pest management (IPM) and insecticide 

resistance management (IRM) strategies. Flubendiamide has been registered on over 200 crops. 

BCS provided information on the general benefits of flubendiamide then examined 15 crops in 

more detail. The crops were selected either because the pounds of flubendiamide applied to the 

crop was relatively high, or the crop had a high percentage of acres treated with flubendiamide 

(Table 1). These crops also represent different EPA crop groups and therefore represent the 

other crops in those groups. BCS selected: soybean, almonds, pistachio, peanuts, tobacco, alfalfa, 

cotton, tomato, pepper, grape, watermelon, broccoli, lettuce, snap bean, and strawberry. 

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Table I. Average Pounds of Flubendiamide Applied Annually in Crops Selected by BCS, and 

t e h A verage P ercent o f C T d rops reate w1 . th Fl u b en d. iam1 . d e. 

Average Pounds A.I. Average Acres Average Percent of 

Crop Applied Annually Treated Crop Treated 

(2011-2013) (2011-2013) (2011-2013) 

Alfalfa 3,000 33,400 0.2 

Almond 14,000 130,000 14 

Broccoli <100 1,700 1 

Cotton 2,900 46,700 0.4 

Grapes, Table <500 3,500 4 

Lettuce 1,100 34,300 13 

Peanut 5,000 65,600 6 

Pepper <500 12,000 15 

Pistachio 1,500 12,000 5 

Snap Beans <500 3,200 1 

Soybean 59,000 960,000 1 

Strawberry <100 1,200 2 

Tobacco 7,000 88,000 26 

Tomato 1,300 30,000 9 

Watermelon 1,000 18,000 14 

BEAD Proprietary Data, 20 I 1-2013. 

Flubendiamide is in the Insecticide Resistance Action Committee's (IRAC) Mode of Action 

(MOA) Group 28, the diamides or ryanodine receptor modulators. In addition to flubendiamide, 

this group contains chlorantraniliprole and cyantraniliprole. Diamides have both nerve and 

muscle effects on insects and there is no known cross resistance to alternative modes of action 

(IRAC, 2015). 

Company data provided by BCS demonstrate that flubendiamide is a unique diamide in that it is 

more selective to Lepidopteran larvae than chlorantraniliprole and cyantraniliprole. The labels 

for chlorantraniliprole and cyantraniliprole include larger pest lists than the flubendiamide label. 

These other pests include grasshoppers, leafhoppers, thrips, beetles, and flies, in addition to 

Lepidoptera. 

BCS asserts that providing a pesticide in a different mode of action group is important to 

insecticide resistance management. This agrees with IRAC (2015) recommendations of rotating 

insecticides with different modes of action to manage resistance. This rotation decreases the 

selection pressure on pest species to reduce the likelihood of developing resistance. However, 

since flubendiamide is not the only diamide, it does not have a unique mode of action, so 

chlorantraniliprole and cyantraniliprole may be used equally for resistance management. 

Non-systemic 

Flubendiamide, unlike the other diamides, is not systemic in the plant. Data provided by the 

registrant does not find any movement of the pesticide in the xylem or phloem of the plants. 

However, it will move from the top of a leaf to the underside, in a process known as 

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translamination. Because of this translaminar property, flubendiamide does not have the residual 

activity of systemic insecticides, but it is more residual than pyrethroids. Information from 

extension entomologists and in several of the Arthropod Management Test results demonstrated 

that flubendiamide was effective for two to three weeks. This was longer than the pyrethroids, 

but shorter than the systemic chlorantraniliprole. Entomologists favor translamination over 

systemic insecticides (such as chlorantraniliprole and cyantraniliprole) as it reduces selection 

pressure on the pest insects and fits well in both IRM and IPM strategies. BEAD agrees that the 

translaminar characteristic is unique to flubendiamide and makes it very suitable for IRM and 

IPM strategies in many crops (BCS, 2015). 

Spec(ficity to Lepidopterans 

BCS provided results of numerous experiments published in the Arthropod Management Tests 

from 2007 to 2013. The results indicated that flubendiamide was very effective at controlling 

various Lepidopteran larvae in their selected crops. Some of the tests were conducted on other 

insects, such as earwigs, which showed that chlorantraniliprole and pyrethroids reduced those 

populations, but flubendiamide had no effect on non-Lepidopteran arthropods. 

BCS (2015) also submitted articles from trade publications, such as Southeast Farm Press and 

Delta Farm Press. The articles highlighted information from University researchers and 

extension agents, many of whom wrote letters to support that flubendiamide is very specific to 

the Lepidopteran pests in their crops, and is also less likely to impact non-target insects and 

cause secondary pest outbreaks. 

BEAD concurs that these data from the Arthropod Management Test as well as the information 

from University entomologists support the registrant's conclusion that flubendiamide is specific 

and effective against Lepidopteran larval pests in the selected crops. 

Protecting Beneficial.\· 

In addition to Arthropod Management Test results, BCS (2015) submitted company data on the 

effects of flubendiamide on several beneficial arthropods. Results indicated little to no mortality 

on many beneficial insects such as ladybird beetles, soldier beetles, predatory mirid bugs, 

predatory mites, and various parasitoid wasps. One study indicated that first instar ladybird 

beetles were moderately harmed, but not all studies had the same result (BCS, 2015). Several of 

the experts mentioned that an early field application of flubendiamide allowed for the build-up of 

predators and parasitoids which prevents the Lepidopteran pests from building up too high 

populations later in the season. This IPM strategy eliminates the potential of a second insecticide 

application (BCS, 2015). The use of beneficials and parasitoids to manage pest populations is an 

important component of IPM. BEAD agrees with BCS that flubendiamide is relatively 

protective of beneficial arthropods, and does play a role in IPM. 

Alternative Insecticides in Selected Crops 

BCS (2015) identified the most likely alternatives to flubendiamide on 15 use sites it analyzed in 

more detail (Table I). Soybeans were selected b/c they represent the largest (highest) user of 

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flubendiamide in terms of total pounds applied annually. Other crops, like almonds, were 

selected because much of the crop is treated with flubendiamide. Other crops were selected 

because they are representative of similar crops of agronomic conditions. BEAD agreed that 

crops BCS selected are representative of the 200 crops for which flubendiamide is registered. 

BEAD analyzed the available usage data for soybean, almond, peppers, tobacco, peanuts, and 

alfalfa to verify the alternative analyses that BCS conducted and reached similar conclusions. 

BEAD did not conduct a comparative product performance analysis and is unable to quantify 

whether multiple applications of alternatives would be necessary to control target pests in the 

respective crops. 

Soybeans 

Lepidopteran pests are important pests of soybeans. Nearly 63 percent of soybean acres 

nationwide are treated annually for these pests, and as much as 75 percent of soybeans in the 

Southeast are treated (BCS 2015). Information provided by extension entomologists (BCS 2015) 

indicate that in much of the southeastern states, com earworm and soybean looper are the 

primary Lepidopteran pests. The available usage data suggests that tobacco budworm and 

armyworm complex are also important Lepidopteran pests in soybeans in terms of acres treated 

(Proprietary Data, 2011-2013). Flubendiamide is used to control Lepidopteran pests on about 1 

percent of U.S. soybeans; however, this use accounts for nearly 50 percent of the total amount of 

flubendiamide used in agriculture (Table 1 ). Since very little soybean acreage is treated with 

flubendiamide, BEAD concludes that it does not provide much benefit to soybean growers, but 

recognizes that this use is important to the registrant since it consists of the most pounds applied. 

BCS (2015) identified that nationwide, lambda-cyhalothrin and bifenthrin (synthetic pyrethroids) 

are the primary insecticides in soybean acres targeting Lepidopteran pests, and that more 

flubendiamide is used in the Southeast soybean production area than in other areas of the country 

(Table 2 summarizes alternatives mode of actions). Caterpillars are more of a problem in the 

Southeast than in the rest of the U.S. BEAD's analysis of the available pesticide usage data 

determined that synthetic pyrethroids were the lead insecticides targeting Lepidopteran larvae. 

BEAD's analysis also shows that the majority of flubendiamide is applied to Southeast soybeans. 

Other insecticides used include diflubenzuron, methoxyfenozide, and chlorantraniliprole, but 

these are applied to fewer acres than flubendiamide. (Proprietary Data, 2011-2013). 

BEAD thinks that the synthetic pyrethroids are the probable alternatives to flubendiamide in 

soybeans because they are currently used more, they are broader-spectrum (so will target more 

pest species), and are less expensive than the other chemistries. However, synthetic pyrethroids 

are known to cause secondary pest problems (e.g., mites) because they are broad-spectrum 

insecticides, and are known to kill many beneficial arthropods, thus requiring multiple 

insecticide applications to maintain control. In their letters of support, several extension 

entomologists mentioned that growers who used flubendiamide did not have to apply additional 

insecticides to control caterpillars later in the growing season because the predators kept the 

populations in check (BCS, 2015). Therefore, if flubendiamide were not available for use, 

soybean growers currently using flubendiamide would need to make multiple insecticide 

applications if they used synthetic pyrethroids to control Lepidopteran pests in soybeans. 

5 
Table 2. IRAC Mode of Actions for Insecticides Targeting Lepidoptera Identified in this 

Document. 

Group Mode of Action Chemical Type Example Chemical(s) Number 

lB Acetylcholinesterase Inhibitor Organophosphates Acephate 

Bifenthrin, 

3A Sodium Channel Modulators Pyrethroids Cyhalothrin, 

Cypermethrin 

5 Nicotinic Acetylcholine Spinosyns Spinetoram 

Receptor Allosteric Modulators Spinosad 

1 lA Microbial Disruptors of Insect Bacillus Bacillus thuringiensis Mid gut thuringiensis 

15 Inhibitors of Chitin Benzoylureas Diflubenzuron Biosvnthesis, Type 0 

18 Ecdysone Receptor Agonists Diacyl-hydrazines Meth ox yfenozide 

22A Voltage-dependent Sodium Indoxacarb Indoxacarb Channel Blockers 

Chlorantraniliprole 

28 Ryanodine Receptor Modulators Diamides Cyantraniliprole 

Flubendiamide 

Almonds 

Almonds constitute the second largest user of flubendiamide in terms of pounds applied, and on 

average, nearly 14 percent of the crop was treated with flubendiamide annually between 2011-

2013 (Table 1 ), indicating high benefits to flubendiamide in almonds. The main Lepidopteran 

pests targeted by insecticide applications are navel orangeworm and peach twig borer, about 40 

percent of insecticide applications target these pests (BCS, 2015). BCS (2015) determined that 

methoxyfenozide, bifenthrin, and chlorantraniliprole are the top three insecticides used to control 

Lepidopteran pests in almonds, followed by flubendiamide (Table 2). BEAD's usage analysis 

had similar results, but determined that more almonds were treated with bifenthrin, then 

methoxyfenozide, followed by chlorantraniliprole (Proprietary Data, 2011-2013). Bifenthrin, a 

synthetic pyrethroid, could be the main alternative to flubendiamide in almonds. However, 

methoxyfenozide, an insect growth regulator, or chlorantraniliprole, another diamide, are more 

likely to be chosen by growers, as data suggest almond growers are selecting more IPM friendly 

insecticides (BCS, 2015). IRM would still be possible if rotation occurred between these 

chemistries. BCS (2015) provided data showing that flubendiamide is less expensive than 

methoxyfenozide and chlorantraniliprole, so growers choosing them may incur higher costs. 

Peppers 

The main Lepidopteran pests on peppers are armyworms. On average, about 47 percent of 

insecticide applications are used to control these pests in peppers (BCS, 2015). While less than 

500 pounds of flubendiamide were applied to peppers on average between 2011 and 2013, nearly 

15 percent of pepper acres were treated with flubendiamide (Table 1 ). Therefore, pepper 

6 
growers are finding flubendiamide to be beneficial. BCS (2015) identified the main alternatives 

to be spinetoram, chlorantraniliprole, methoxyfenozide, zeta-cypermethrin, and cyfluthrin (Table 

2). BEAD's usage analysis identifies these same chemicals to be the primary insecticides for 

these pests (Proprietary Data, 2011-2013). BEAD thinks that pepper growers currently using 

flubendiamide are likely to select chlorantraniliprole, another diamide, to replace flubendiamide, 

because the data indicate pepper growers are choosing more IPM friendly insecticides, even 

though they are more expensive than synthetic pyrethroids (BCS, 2015; Proprietary Data, 2011-

2013). 

Tobacco 

About 6,000 pounds of flubendiamide were applied annually to tobacco on average between 

2011 and 2013, and about 26 percent of tobacco acres were treated (Table 1), indicating that 

flubendiamide has high benefits to tobacco growers. The primary Lepidopteran pests are 

tobacco budworm and tobacco hornworm. BCS identified flubendiamide as the second most 

used insecticide, after chlorantraniliprole, then followed by spinosyn and lambda-cyhalothrin. 

BEAD's usage analysis found that the top insecticides targeting these pests are acephate, 

Bacillus thuringiensis, chlorantraniliprole, flubendiamide, and spinosyn (Table 2) (Proprietary 

Data, 2011-2013). Growers currently using flubendiamide are choosing an IPM and IRM 

compatible insecticide; therefore, if flubendiamide were not available for use, BEAD thinks 

growers would likely choose chlorantraniliprole or spinosyn over an organophosphate or 

synthetic pyrethroid, which are not compatible with IPM and IRM strategies. 

Peanuts 

On average, over the years 2011-2013, about 5,000 pounds of flubendiamide were applied to 

about 6 percent of peanut acres grown (Table 1). BCS' and BEAD's usage analysis determined 

that the most used Lepidopteran insecticides on peanuts are diflubenzuron, bifenthrin, and 

lambda-cyhalothrin. BCS found that methoxyfenozide was the fourth most used insecticide for 

control of Lepidopteran pests (Table 2), whereas BEAD found that esfenvalerate, another 

synthetic pyrethroid was the fourth most used insecticide. BCS thinks that synthetic pyrethroids 

would likely replace flubendiamide to control Lepidopteran pests in peanuts. Since data indicate 

that many acres are treated with synthetic pyrethroids, BEAD agrees that peanut growers are 

likely to choose them to replace flubendiamide. Not only will growers likely have to make 

multiple insecticide applications to replace flubendiamide since synthetic pyrethroids are broad 

spectrum insecticides and their use can cause secondary pest problems (e.g. mites), but synthetic 

pyrethroids use the same mode of action, thereby limiting IRM strategies. 

Alfa(fa 

Nearly 60 percent of insecticides applied to alfalfa target Lepidopteran pests. On average, over 

the years 2011-2013, about 4,000 pounds of flubendiamide were applied to Jess than one percent 

of alfalfa acres grown (Table l). BCS (2015) found that the insecticides with the highest usage 

on alfalfa are lambda-cyhalothrin, cyfluthrin, z-cypermethrin, and indoxacarb (Table 2). 

BEAD's usage analysis had similar results but with a slightly different ranking. The most likely 

alternatives to flubendiamide are the :l)'nthetic pyrethroids. Synthetic pyrethroids are broad-

(·. 

r 

7 
spectrum insecticides and tend to result in population explosions of secondary pests, since all the 

beneficial arthropods are killed. If current flubendiamide users switched to synthetic 

pyrethroids, the absence of predators and parasitoids will allow pest populations to increase, 

resulting in more applications of insecticides, but this would be on a very small percent of alfalfa 

acres. 

Conclusions 

While there are some differences in BCS ' and BEAD's analysis of the potential alternatives to 

flubendiamide, they are minor. The reliance on synthetic pyrethroids reduces the ability to 

manage IRM by using insecticides with different modes of action. IPM strategies try to employ 

specific insecticides that target the pests while allowing beneficial arthropods to survive. 

Synthetic pyrethroids are broad spectrum insecticides and do not fit well with most IPM 

practices. BEAD agrees with BCS that synthetic pyrethroids are the likely alternatives to 

flubendiamide in alfalfa, peanuts, and soybeans; but these crops have very few acres treated with 

flubendiamide, and consequently little benefit to those growers. However, based on its analysis 

of the available usage data, BEAD thinks that growers of almonds, peppers, and tobacco that 

have chosen to use IPM friendly flubendiamide, are likely to continue to select IPM friendly 

alternatives, such as insect growth regulators (e.g., diflubenzuron, methoxyfenozide), other 

diamides (e.g., chlorantraniliprole, cyantraniliprole), and spinosyns (e.g., spinetoram). In 

addition, these crops have higher acres treated with flubendiamide indicating higher benefits. 

References 

BCS. 2015 . Bayer CropScience Benefits Document Supporting the Continued Registration of 

Flubendiamide (Belt SC). EPA MRID No. 49533001. 

BEAD Proprietary Data, 2011 -2013 . 

Insecticide Resistance Action Committee. 2015. Mode of Action. Available at: 

http //1Aw1A mtc onl111c org/rnode~ or action/ Accessed: June 22, 2015. 

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