United States Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Administrative action to change D301-81-10(3) and D301.81-

10(8) in the Treatment Manual

Treatment Evaluation Document (TED)

Date: June 20, 2012

Treatments, Pests, and Commodities 

New Treatment/ 

Revision/Deletion 

Treatment 

Type

Target Pests Commodity Applicable

New treatment Bifenthrin Solenopsis

invicta; 

Solenopsis 

richteri and 

hybrid

(Imported 

Fire Ant)

Balled-and-burlapped 

plants/nursery stock; 

immersion/dip application

New treatment Bifenthrin Solenopsis

invicta; 

Solenopsis 

richteri and 

hybrid

(Imported 

Fire Ant)

Commercial Grass sod

Clarification of 

application 

method

Drench 

method on 

balled-andburlapped 

plants

Solenopsis

invicta; 

Solenopsis 

richteri and 

hybrid

(Imported 

Fire Ant)

Balled-and-burlapped 

plants/nursery stock; 

drench application
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Objective: To provide supporting information and justification for additional treatments 

being proposed for the Imported Fire Ant (IFA) quarantine in the Treatment Manual. 

The change is to help continue domestic trade of nursery stock from areas of the U.S.

infested with Solenopsis invicta, Solenopsis richteri and the hybrid (Imported Fire Ant).

Overview: In order to limit the artificial spread of the Imported Fire Ant, domestic 

movement of all nursery stock (containerized or balled-and-burlapped) and grass sod

from IFA-infested areas of the U.S. to uninfested areas is regulated under 7 CFR 301.81-

2. Current approved treatments for balled-and-burlapped (B&B) nursery stock is limited 

to the use of one insecticide, chlorpyrifos, and availability of that insecticide is very

limited, with only a handful of EPA approved labels with pest, commodity and required 

quarantine level effective rates of application. Treatment of grass sod is similarly limited 

by available EPA approved insecticide labels. While 2 insecticides are APHIS approved, 

no chlorpyrifos labels for grass sod and IFA at quarantine level rates of application are 

available (use pattern has been cancelled/removed from labels due to EPA chlorpyrifos 

concerns). Grass sod can be treated with granular fipronil, but many sod growers are not 

comfortable with granular applications, nor have granular application equipment. 

Therefore, CPHST is continually pursuing additional quarantine level treatment options 

and better application techniques for growers to comply with the Imported Fire Ant 

quarantine.

Evaluation: 

Bifenthrin immersion treatment for balled-and-burlapped nursery stock: CPHST, along 

with Tennessee State University, have evaluated the use of bifenthrin as an immersion 

treatment for balled-and-burlapped nursery stock for 2-4 years. The results found that a 

dip rate of 0.115 lb ai/100 gal water provided 6 months of residual activity against IFA. 

Thus, CPHST recommended the addition of this treatment option to the Treatment 

Manual.

Bifenthrin treatment for grass sod: CPHST, along with Tennessee State University, have 

evaluated the use of bifenthrin as a grass sod treatment for over 2-3 years. The results 

found bifenthrin liquid applied in two applications, one week apart, as a broadcast 

application at a rate of 0.2 lb ai/acre provided 16 weeks of residual activity against IFA 

after a four week exposure period. Thus, CPHST recommended the addition of this 

treatment option to the Treatment Manual.

Clarification of application method for drench treatment of balled-and-burlapped 

nursery stock: During drenching, B&B normally rests on one side of the root ball 

throughout the three-day drench process (drench twice a day for 3 consecutive days). 

This drench method possibly restricts treatment coverage on the resting side, while giving 

the surface of direct application a higher concentration of chemical and deeper 

penetration. Trials conducted by CPHST and Tennessee State University in the mid2000s, strongly suggested that rotating root balls during treatment, regardless of 

application frequency, improved the consistency of bioassay results and could potentially

cut the number of days spent applying drenches from three down to one. Numerous trials 
3

have been conduct since 2005 to examine whether changes in plant handling during 

application improved penetration and coverage and whether we could possibly reduce in 

the number of days required to complete a drench. It is clear that rotating root balls 

during treatment application leads to a more uniform coverage of the spray treatment and

more consistently effective bioassay results. Thus, CPHST is recommending adding 

language to the Treatment Manual to strongly recommend that growers rotate the B&B 

root balls between daily applications for the current chlorpyrifos treatment.

Reports available online at the APHIS-PPQ-CPHST Gulfport Lab annual reports 

webpage: 

http://www.aphis.usda.gov/plant_health/plant_pest_info/fireants/gulfport.shtml

Addition to Treatment D301.81-10(3): Nursery Stock Balled or in Containers Method 

A – Immersion: After Certification Period and Important Notice for Emulsifiable 

Chlorpyrifos Treatment of Balled or Containerized Plants:

Pesticide: Bifenthrin (Liquid – label must have use pattern)

Dosage:

Table 5-8-XX Bifenthrin Liquid Dosage for Balled or Containerized Plants

Bifenthrin Dosage

Liquid with use pattern on label 0.115 lb ai/100 gal. water

Exposure Period: Plants certifiable immediately upon completion of treatment.

Certification Period: 180 days

Important: The professional user assumes responsibility for determining if bifenthrin is 

safe to treat plants under commercial growing conditions.
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Addition to Treatment D301.81-10(8): Grass – Sod Add to Table 5-8-9 and modify title

Table 5-8-9. Dosages for Grass Sod

Material Amount and dosage of 

material

Certification 

Period

Exposure 

Period

Chlorpyrifos 8.0 lb ai/acre 6 weeks (after 

exposure period)

48 hours

Fipronil-granular 0.0125 lb ai/acre applied in 2 

applications 1 week apart for 

total of 0.025 lb ai/acre

20 weeks (after 

exposure period)

30 days

Bifenthrin-liquid 0.2 lb ai/acre applied in 2 

applications 1 week apart for 

total of 0.4 lb ai/acre

16 weeks (after 

exposure period)

4 weeks (28 

days)

Additional language to clarify application technique for Treatment D301.81-10(3) 

Nursery Stock – Balled or in Containers Method B – Drench Balled-and-Burlapped 

(B&B) Plants: Step 2 Apply the solution: 

Apply the chlorpyrifos solution as a substitute for plain water to the plants during the 

routine watering activities. Do not remove burlap wrap from plants prior to treatment. 

Treat plants singly or in groups with the chlorpyrifos solution to the point or runoff on a 

twice daily schedule for three consecutive days. Rotate the root ball between applications 

to insure all sides of the root ball are sufficiently treated.

Decision: Amend the Treatment Manual under D301.81-10(3) and D301.81-10(8) to add 

a new immersion treatment using bifenthrin for B&B nursery stock and a new broadcast 

treatment using bifenthrin for grass sod. Amend the language under D301.81-10(3) for 

the drench application technique for B&B plants to include rotating the root ball between 

insecticide applications.

Originator: Charles L Brown, PPQ-EDP-IFA National Program Manager

Anne-Marie Callcott, PPQ-CPHST, Entomologist