### 1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES



### PC Code: 044309

Date: October 21 , 2009

DP Barcode: 370427

MEMORANDUM

SUBJECT: Clothianidin Registration of New Products and New Uses of Sepresto

75WS and PROCEEDTM OPTIMUM: Addendum to Address Mitigation

of Bee Hazard

FROM: Allen W. Vaughan, Entomologist

Environmental Risk Branch V Environmental Fate and Effects Division (7507P)

THROUGH: Mah T. Shamim, Branch Chief

Environmental Risk Branch V

En vironmental Fate and Effects Division (7507P)

TO: Kable Davis, Risk Manager Reviewer Venus Eagle, Risk Manager Meredith Laws, Branch Chief

Insecticide-Rodenticide Branch Registration Division (7505P)

EFED recently conducted a risk assessment for a number of proposed new agricultural

uses f or clothianidin products, under DP355370. That assessment characterized the potential ha zard to foraging pollinators from uses of clothianidin on flowering plants.

This adde ndum addresses in more detail the potential hazards to pollinators by identifying hazards for each crop and specific application method, and suggests measures to mitigate hazards for foliar uses of clothianidin. Because of the extreme persistence of

c lothianidin in soil environments (half-life = 148 to 1,155 days) and the potential for

tra nslocation of this systemic pesticide to pollen and nectar, EFED does not believe that precautionary bee labeling language will effectively mitigate hazards from soil treatment or seed application of clothianidin to cucurbits and fruiting vegetables. In addition, succeeding berry crops or rotational crops that are planted following soil treatment or seed application have the potential to expose bees to residues of clothianidin in the soil.

### 2

Background:

Clothianidin is a systemic nicotinoid insecticide that may be applied via foliar, soil, or seed application. Due to its systemic properties, it may be present in/on plant tissues following any method of application. Clothianidin is also highly toxic to bees on both an

a cute contact and oral exposure basis (LD 50 

### = 0.0439 and 0.0037 ug a.i./bee

,

re spectively), and is extremely persistent in soil environments. Thus, there is a concern from the proposed soil and seed treatment uses as well as proposed foliar application

uses.

The new uses involved in this request are leafy vegetables, Brassica leafy vegetables, fruiting vegetables, cucurbits, and low-growing berries, except strawberries (both foliar

a nd soil); tree nuts, figs, pomegranates, cotton, peach es
, an d soybeans (foliar only ).

Attached is a table developed by David Brassard of BEAD which provides detailed information regarding the potential for bee exposure from the proposed new uses. The information in the attached table regarding relative risk may be summarized as follows:

L ow potential for exposure to bees : Brassica leafy vegetables and leafy vegetables (crops are harvested prior to bloom); figs (bees are unlikely to visit this crop).

Moderate /high potential for exposure, but risk may be mitigated for foliar uses if label precautions (which prohibit application prior to and during bloom) are

followed : foliar application to low-growing berries, cotton, cucurbits, fruiting vegetables, peaches, pomegranates, soybeans, and tree nuts.

Potential for exposure in pollen/nectar following soil treatment : cucurbits, fruiting vegetables, and berries. Because clothianidin is extremely persistent in soil and is a

s ystemic pesticide, there is a potential for th is chemical to be translocated from the soil up through the plant into pollen and nectar. Translocation of clothianidin from the soil to the pollen and nectar of canola has been demonstrated in field studies conducted with clothianidin-treated seeds. In addition, studies conducted by Bonmatin 2005 have found that the nitroguanidine neonicotinoid, imidacloprid, which is in the same chemical class as clothianidin, translocates from the soil to the pollen of corn and sunflower plants. 1


### Thus, there is a risk concern for pollinators foraging on blooming plants following seed or soil treatment. In addition because clothianidin is persistent in soil, residues may

re main in the soil and be translocated into the nectar and pollen of succeeding and rotational crops. The potential for exposure of pollinators to clothianidin via this route is sig nificant, but mitigation measures have not been developed to protect bees from

e xposure to soil-applied systemic pesticides.

1 Bonmatin, J.M., P.A. Marchand, R. Charvet, I. Moineau, E.R. Bengsh, and M.E. Colin. 2005. Quantification of Imidacloprid Uptake in Maize Crops. J. Agric. Food Chem . 53: 5336-5341; Bonmatin, J.M., I. Moineau, R. Charvet, M.E. Colin, C. Fleche, E.R. Bengsch. 2005. Behavior of Imidacloprid in Fields. Toxicity for Honey Bees. In Environmental Chemistry: Green Chemistry and Pollutants in Ecosystems , ed. E. Lichtfouse, J. Schwarzbauer, D. Robert. New York: Springer.

### 3

Potential for Honeybee Exposure to Clothianidin by Crop and Application Method

Crop/Crop Group P ests application method Likelihood of application during

bloom 1 Potential for

honeybee

visitat io n 2

berries (low

growing) Cranberry weevil, flea beetles, Foliar post bloom Low High Soil post bloom None 3 High Brassica leafy vegetables Aphids, fl ea beetles, leafhoppers,

whiteflies Foliar Low Low

Soil None Low

Cotton Aphids, Lygus bugs, whiteflies foliar High Moderate

Cucurbits Aphids, flea beetles, leafhoppers,

whiteflies Foliar High High

Soil Medium

- High 4 High Figs Dried fruit beetle, f ig scale, vinegar

flies Foliar post bloom Low Low

Fruiting vegetables Aphids, Colorado potato beetle, flea

beetles, leafhoppers, Lygus bugs, pepper weevil, stink bugs, whiteflies Foliar High Moderate

Soil Medium

- High 4 Moderate

leafy vegetables Aphids, flea beetles, leafhoppers,

whiteflies Foliar Low Low

Soil None Low

Peaches Aphids, leafhoppers, plum curculio,

scale, stink bugs Foliar post bloom Low High

Pomegranates Aphids, leafhoppers, sharpshooters,

whiteflies Foliar post bloom Low Moderate

So ybean s Aphids, bean leaf beetle, leafhoppers,

Lygus bugs, stink bugs, whiteflies Foliar High Moderate

Tree Nuts Aphids, hickory shuckworm,

leafhoppers, leafhoppers mealybugs, pecan nut casebearer, scale, whiteflies Foliar post bloom Low High

1 Likelihood of application during bloom primarily determined by the presence of damaging pest populations during the blooming period ; if growers adhere to the label restrictions against application during bloom, all of the entries in th is column would be "low" except for berries, cucurbits, and fruiting vegetables.

2 Potential for honeybee visitation : high : crop frequently pollinated by honeybees transported to the field by commercial migratory beekeepers; moderate : crop naturally pollinated by honeybees and other pollinator species; l ow : crop does not require pollination by honeybees to reach marketable stage

3 Soil application of clothianidin to succeeding berry crops or rotational crops may pose a hazard to bees

from residues that remain in the soil.

4 The current label allows clothianidin to be applied to cucurbits and fruiting vegetables as a soil treatment at any time from planting through 7 days pre-harvest. Because this chemical is persistent in soil environments and systemic, any soil treatment prior to or during bloom may result in residues in pollen and nectar. Thus, there is a potential for hazard to pollinators even if the application is not made during bloom. Mitigation measures have not been developed to protect bees from this route of exposure

.