Bumble Bee Deaths / Linden TreesDinotefuran and Imidacloprid

STATE FIFRA ISSUES RESEARCH & EVALUATION GROUP (SFIREG)POM WORKING COMMITTEE

September 16, 2013

Rose KachadoorianOregon Department of Agriculture

Background - Dinotefuran

• Two incidents involving dinotefuran, the active ingredient in Valent/Safari occurred within a two week period in June 2013. Pollinator Week in the U.S.

• Both incidents involved the death of a large number of bumble bees and linden trees (Tilia cordata).

• Most bees were Bombus vosnesenskii. Some researchers estimate the number of bees impacted to be 59,000.

• The two incidents involved different timing, and application methods (broadcast, drench and basal bark application).

Wilsonville Incident

•Applicators originally came to the site to treat other plant species for black vine weevils. But then noticed aphids on the linden trees.

•Linden trees were in bloom. Allegedly bees were not present at the time of application.

•Foliar (primarily) and soil drench applications were made early in the morning in June (approx. 6:30 a.m.). Shoppers at Target store started to complain - dead and dying bees were falling on their cars.

Details - Wilsonville

55 Linden trees were treated. Trees were approx. 25-30 ft tall.

Details - Wilsonville

Foliar Application Rate• Label allows for foliar

application 4-8 oz. per 100 gallons of water.

• Application rate - 6 oz. per 100 gallons

Details - Wilsonville

Note - A few trees that had cars parked nearby received a soil drench application.

Wilsonville

Dead Bumble Bees were swept up frequently over a period of several days by the retail store.

Customers and other community members were concerned by the number of dying and dead bees.

According to reports, “still living bees were acting like they were drugged, spinning on the asphalt while others clung and buzzed crazily among the flowers.”

Community members held a funeral.

Where did all the bumble bees originate?

The Shopping Complex is located on the edge of agricultural fields, including a large clover grown for seed field.

Historically the clover field has been pollinated with managed honey bees, but the bumble bee population had been encouraged.

Wilsonville Oregon

June Treated Linden Trees

Clover Field

12 honey bee hives nearby site. Beekeeper has filed a Report of Loss form with ODA.

Generated National and International Press and Attention

Recovery Effort - Wide range of options discussed to minimize further bee mortality with the City of Wilsonville, Valent, University and the Xerces Society.

Options Included: defoilating trees, shearing trees, removing flowers, applying a repellent, cutting the trees down, and using shade cloth.

Netting trees with shade cloth was selected as the best option.

Action was taken to reduceadditional exposure

While ODA personnel and others were finishing bagging the trees in Wilsonville, we received a call regarding dead bees in the nearby city of Hillsboro.

187-200 trees were treated (bark treated). More lindens than any other species. The root flare and approx. 4 ft up the tree trunk were treated.

This was the third year an application had been made.

The application was made in late March 2013, and none of the trees were leafed out at the time of application.

Information provided by the City of Hillsboro indicated that 16 oz. product /one gallon water was used.

Hillsboro Incident - Dinotefuran

Safari Supplemental (“Updated Orn. Plant Applications and Trunk Spray in trees and large shrubs) – Slightly older product, EPA Reg. No. 33657-16-59639. No bee statement on Supplemental Label.

The majority of bee deaths were only associated with one stressed tree. The linden tree appears to have been stressed for a while. The leaves were tiny, but the blooms appeared to be the same number and size as the surrounding trees.

Leaves, flowers and bees were sampled.

To reduce further bee mortality, the stressed “Killer Tree” was bagged with shade cloth.

Hillsboro Incident - Dinotefuran

ODA Concern – Were linden flowers (pollen/nectar?) from a tree treated in March 2013 (bark), toxic to bumble bees in June 2013?

Stressed Linden Tree / Dead Bumble Bees

Hillsboro – March Treatment

In June, ODA began the time consuming process of collecting information, analyzing samples and thoroughly investigating the Wilsonville and Hillsboro incidents.

ODA also responded to numerous additional reports by concerned citizens.

Laboratory results show that bees, flowers and leaves from treated trees are positive for dinotefuran. Lab data will be released at the completion of the investigation/review.

ODA Process

• Because of the complexity of the investigative process (various application methods had been used at different times in multiple locations), ODA needed time to fully investigate the Wilsonville and Hillsboro incidents, and evaluate the data.

• There was concern about the potential of additional large bee kills during the summer due to additional applications.

• The Director’s Office spoke with agricultural interests about the seriousness of the cases and possible directions.

Process

ODA determined that a temporary rule:

1Was necessary to prevent any additional applications of dinotefuran and thereby minimize potential further negative impacts to pollinating insects. The department needed to complete its investigation and have additional information.

2Will protect pollinating insects while the department completes its evaluation and investigation of the incidents, and determines if there is a wide-spread problem requiring additional regulatory action.

3Will allow the department time to collaborate with OSU bee experts and federal partners including EPA.

ODA -Statutory Authority to Enact a Temporary Rule.ORS 561.020; ORS 634.322(6); ORS 634.900; ORS chapter 183

Process

In an Abundance of Caution, ODA Adopted a Temporary Administrative Rule OAR 603-057-0386

“Any application, regardless of application method*, of a pesticide product containing the active ingredient dinotefuran on plants is prohibited.

This includes,but is not limited to, applications on landscape trees and shrubs, nursery andgreenhouse plants, turfgrass, forests and agricultural crops.”

In effect for 180 days (June 27 – December 24, 2013)

* Including soil application & chemigation

How Many Products Were Affected By The Temporary Rule?

19 products from several different registrants.

Non-plant uses are allowed. Such as indoor ant and roach control or as a topical treatment on pets to control fleas and ticks.

Additional Bee Calls from Concerned Citizens generated follow-up investigations.

Additional bee kills associated with linden trees at two more locations in August 2013.

Product used at both locations, MANA Imidacloprid 2F (EPA Reg. No. 66222-203).

Both applications were

soil drench applications.

August 2013, Additional IncidentsPortland – Two Locations (Imidacloprid)

Timing: One application was made in March 2013, and the other May 2013.

New incidents resemble Hillsboro situation. Trees were not in bloom at the time of application.

Number of bees killed much smaller than Wilsonville location, and also bloom was nearly completed in Wilsonville.

Laboratory analysis indicate that that bees were exposed to imidacloprid, and imidacloprid was present on the linden leaves and blossoms.

More questions than answers at this time.

Portland – Two Locations (Imidacloprid)

Linden trees and Native Bumble Bees*

Preliminary Data Review Indicates:

Some lindens secrete mannose, a sugar that is toxic to bumble bees.

Some researchers are concerned that there may be a synergistic effect of mannose and insecticides.

* Honey bees can also be affected

Currently, state agencies and EPA are focused on developing understandable and enforceable label language which adequately mitigates risk to pollinators.