March 26, 2015

MN Landscape Arboretum

Toxic Substances Hydrology Program

Environmental Health Mission Area

U.S. Geological Survey

Dana W. Kolpin and Michelle L. Hladik

Widespread occurrence of

Neonicotinoid insecticides in

streams across the U.S.

Neonicotinoids in the News• Implicated in Colony Collapse Disorder (CCD) in honeybees

- worker bees abruptly disappear

• Risk to other pollinators (bumble bees, butterflies)

What are neonicotinoids?- Neurotoxic insecticides developed to replace OPs and

carbamates. Structurally similar to nicotine.

- active against a broad spectrum of insects

- potent at low doses

- provide long term control

- active systemically (taken up throughout entire plant)

- Strongly bind to insect nAChRs (nearly irreversible).

- block nerve receptors in open position

- constant neuromuscular stimulation leads to death

- Highly water soluble with long aqueous and soil half-lives.

clothianidin thiamethoxamimidacloprid

S

N

HN

N

HN

NO2

Cl

NCl

N

N

HNNO2

S

N

HN

N

N

NO2

Cl

O

Many products Few ingredients

Home use- pets: topical

- lawn and garden: foliar spray, granular, tree injection

Agricultural use- row crops: foliar spray, seed treatment

- pasture: granular

Most widely used class of insecticides worldwide.

- Use of treated seeds has tripled in last decade.

- nearly all corn and 1/3 of soybeans

- Almost all clothianidin use is as seed treatments.

Rapid increase in the agricultural

use of Neonics

Environmental Fate

http://sitn.hms.harvard.edu/wp-content/uploads/2014/12/CB-FIgure-1.jpg

Nationwide sampling (2012-2014)

Results of nationwide study

Neonic Detection

1 or more: 53%

2 or more: 26%

3 or more: 11%

5 or more: 3%

Sand Run Gulch near Parma, ID

Neonic Land Use S. rhoClothianidin row crops +0.47 (0.003)

Thiamethoxam row crops +0.47 (0.003)

Imidacloprid urban +0.47 (0.003)

Hladik and Kolpin, in prep

(3%)

(16%)

Midwest in heart of heavy neonic use

2013 Midwest Neonics Study

Hladik et al., 2014

(59-86% rowcrops)

(21-36% rowcrops)

Most Commonly Detected Neonics

Neonics detected at

all 9 sites (and in

multiple samples).

Multiple neonics

detected in 43 of 79

samples (28 of 29

during May-June).

Levels can exceed

chronic toxicity for

imidacloprid.

Imidacloprid chronic

exposure toxicity level

(35 ng/L)

To

tal N

eo

nic

oti

no

id C

on

ce

ntr

ati

on

(n

g/L

)

0

100

200

300

400

500

Monthly Sites

Old Mans Creek

Mar Apr May Jun Jul Aug Sep Oct

Temporal Results - 2013

- Classic “spring flush” phenomena as herbicides (atrazine)

- likely association with seed treatments

Transport driven by use and precip

Streams during elevated

flow conditions: IA, 2014

Flow Cloth Thia Imid

Site Date (cfs) (ng/L) (ng/L) (ng/L)

Omaha 6/19/13 40,700 18 11 4.4

6/18/14 73,300 25 18 11

Fulton 6/24/13 973 74 40 4.8

6/19/14 2,720 98 40 11

Old Mans 6/26/13 1,240 84 26 23

7/01/14 5,560 68 20 25

Wapello 7/01/13 50,000 62 30 15

7/03/14 107,000 53 20 19

Big Sioux 6/20/14 64,300 77 38 20

Garber 6/20/14 25,000 132 73 26

Comparison of 2013 to 2014

a

b

c

Streams in an important ecosystem:

Chesapeake Bay (2014)

Antietam Creek near Sharpsburg, MD

2014

Apr May Jun

To

tal N

eo

nic

otino

id C

once

ntr

atio

n (

ng

L-1

)

0

10

20

30

40

Dis

cha

rge

(m

3 s

-1)

1

10

100

Clothianidin

Thiamethoxam Chronic Toxicity

a

Big Pipe Creek at Bruceville, MD

2014

Apr May Jun

To

tal N

eo

nico

tino

id C

onc

ent

ratio

n (n

g L

-1)

0

50

100

150

Dis

cha

rge

(m

3 s

-1)

0.1

1

10

100Clothianidin

Thiamethoxam

Chronic Toxicity

Chillisquaque Creek at Chillisquaque, PA

2014

Apr May Jun

To

tal N

eo

nico

tino

id C

onc

ent

ratio

n (n

g L

-1)

0

50

100

150

200

Dis

cha

rge

(m

3 s

-1)

0.1

1

10

100

Clothianidin

Imidacloprid

Thiamethoxam

Chronic Toxicity

b

c

Antietam Creek near Sharpsburg, MD

2014

Apr May Jun

To

tal N

eo

nic

otino

id C

once

ntr

atio

n (

ng

L-1

)

0

10

20

30

40

Dis

cha

rge

(m

3 s

-1)

1

10

100

Clothianidin

Thiamethoxam Chronic Toxicity

a

Big Pipe Creek at Bruceville, MD

2014

Apr May Jun

To

tal N

eo

nic

otino

id C

once

ntr

atio

n (

ng

L-1

)

0

50

100

150

Dis

cha

rge

(m

3 s

-1)

0.1

1

10

100Clothianidin

Thiamethoxam

Chronic Toxicity

Chillisquaque Creek at Chillisquaque, PA

2014

Apr May Jun

To

tal N

eo

nic

otino

id C

once

ntr

atio

n (

ng

L-1

)

0

50

100

150

200

Dis

cha

rge

(m

3 s

-1)

0.1

1

10

100

Clothianidin

Imidacloprid

Thiamethoxam

Chronic Toxicity

b

cAntietam Creek near Sharpsburg, MD

2014

Apr May Jun

To

tal N

eo

nic

otino

id C

once

ntr

atio

n (

ng

L-1

)

0

10

20

30

40

Dis

cha

rge

(m

3 s

-1)

1

10

100

Clothianidin

Thiamethoxam Chronic Toxicity

a

Big Pipe Creek at Bruceville, MD

2014

Apr May Jun

To

tal N

eo

nic

otino

id C

once

ntr

atio

n (

ng

L-1

)

0

50

100

150

Dis

cha

rge

(m

3 s

-1)

0.1

1

10

100Clothianidin

Thiamethoxam

Chronic Toxicity

Chillisquaque Creek at Chillisquaque, PA

2014

Apr May Jun

To

tal N

eo

nic

otino

id C

once

ntr

atio

n (

ng

L-1

)

0

50

100

150

200

Dis

cha

rge

(m

3 s

-1)

0.1

1

10

100

Clothianidin

Imidacloprid

Thiamethoxam

Chronic Toxicity

b

c

21% Ag: 11 ng/L Cloth+Thia 32% Ag: 64 ng/L Cloth+Thia 41% Ag: 93 ng/L Cloth+Thia

- clothianidin: 59%

- thiamethoxam: 29%

- imidacloprid: 6%

Chronic toxicity levels

exceeded in 2 samples (12%)

Transport driven by use and

precipitation

a

b

c

Temporal patterns in urban streams: GASope Creek near Marietta, GA

2012

Oct Jan Apr Jul Oct Jan Apr Jul Oct

Imid

acl

orp

id C

onc

ent

ratio

n (n

g L

-1)

0

20

40

60

80

100

Dis

cha

rge

(m

3 s

-1)

0.01

0.1

1

10

100

Imidacloprid

2013 2011

Chronic Toxicity

Chattahoochee River near Whitesburg, GA

2011

Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct

To

tal N

eo

nico

tino

id C

onc

ent

ratio

n (n

g L

-1)

0

20

40

60

80

100

120

140

Dis

cha

rge

(m

3 s

-1)

1

10

100

1000Imidacloprid

Dinotefuran

Acetamiprid

2012

Chronic Toxicity

a

b

: 39% urban

: 18% urban

9% pasture67 samples collected

on a fixed schedule

- imidacloprid: 87%

- dinotefuran: 10%

- acetamiprid: 7%

(90%)

(79%)(32%)

(5%)

No relation to stream flow

Clothianidin

Imidacloprid

December 2012 June 2013

Instream transport:

Fourmile Creek

(Ankeny, IA)

Dec, 2012

99% effluent

June, 2013

11% effluent

- Conservative instream

transport of neonics

along 4.8 km reach.

- Imidacloprid levels in

effluent higher compared

to clothianidin.

De Perre et al., 2015

Southern Illinois University

Hladik et al., 2014

U.S. Geological Survey

Planting of treated seeds

promotes neonic transportOld Mans Creek near Iowa City, IA

Dis

ch

arg

e (

m3/s

ec

)

0.01

0.1

1

10

100

Clo

thia

nid

in (

ng

/L)

0

100

200

300

ND

Mar Apr May Jun Jul Aug Sep Oct

Seed Treatment Paradox

Logic

Touted as a better management practice

over broadcast application

- dual action control

- provides a barrier around seed

- systemic agent absorbed by new roots

- proactive (preventing infestation will increase yields)

- targeted application (less chemical use compared

to broadcasting)

Seed Treatment ParadoxDoes seed treatment translate to decreased

insecticide use (clothianidin vs chlorpyrifos)?

Individual field scale?

- for 100 acre field, clothianidin use would be 7%

that of chlorpyrifos

Statewide scale with ubiquitous seed treatment?

- 2013 clothianidin use is 99% that of the 2001

chlorpyrifos use

- Similar use but on substantially more crop acres

Millions of acres of prophylactic neonic use in Iowa

Yes

No

Seed Treatment Paradox

Reality1. At statewide level, does not translate to less use.

2. EPA study found no increase in soybean yields

through use of treated seeds.

3. Can unintentionally reduce crop yields - slugs unaffected by neonic exposure via treated seeds

- slugs transmitted toxins to predaceous beetles

- decreased predaceous beetle population

- increased slug population

- reduced soybean yields (Douglas et al., 2015)

4. Contributes to widespread neonics in streams- unknown environmental impact

- Neonics frequently detected in streams across U.S.- Can exceed chronic and even acute levels

- Contributions from both urban and Ag use

- Transport in Ag settings driven by use and precip.- Current use patterns creating a “spring flush” of

neonics in Midwestern streams

- Seed treatments are increasing overall neonic use

across the U.S. translating to increased neonic

detections in U.S. streams.

- More research needed to understand potential

environmental effects from exposures via neonic

levels in streams.

Summary

Questions?

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