United States Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Addition of a Cold Treatment Schedule T107-l to the 

Treatment Manual for Peach Fruit Fly Bactrocera 

zonata (Saunders) in Oranges and Tangerines

Treatment Evaluation Document

Date: Febuary 07, 2012

Treatments, Pests, Commodities and Countries

New Treatment/ 

Revision/Deletion 

Treatment 

Type

Target Pests Commodity 

Applicable

Country(ies) 

of origin

New Treatment Cold Treatment Bactrocera 

zonata

(Saunders)

Citrus 

sinensis L.

(Osbeck)

and Citrus 

reticulata

All

Objective: This document provides supporting information and justification for the 

addition of a new treatment schedule (proposed to be T107-l) to the PPQ Treatment 

Manual. The new treatment is needed to mitigate risks from the introduction of peach 

fruit fly (PFF), Bactrocera zonata (Saunders) in oranges (Citrus sinensis) and tangerines 

(Citrus reticulata). This addition specifically will enable Egypt to resume importations

of oranges and tangerines into the United States, which were suspended following 

detection of peach fruit fly in 2002 (USDA, 2002).

Overview: Oranges and tangerines from Egypt have been enterable to the United States 

since 1969 subject to cold treatment T107-a for Mediterranean fruit fly, Ceratitis capitata

(USDA, 1969). Importation of oranges from Egypt was suspended in July 2002 because 

of the establishment of PFF in Egypt (USDA, 2002). Egypt requested that APHIS 

reconsider the use of cold treatment T107-a to allow the importation of oranges and 

tangerines based on the treatment efficacy data that they had developed for Bactrocera

zonata in Citrus (MALR, 2008). In a study conducted in 2006, researchers treated citrus 

fruit infested with 31,900 third instar Bactrocera zonata larvae for 13 days at 1.7°C with 
2

a 2 day pre-cooling period and found no survivors (PPRI, 2006; Mohamed and El 

Wakkad, 2009). This was followed by two subsequent studies in 2011 at Food and 

Agricultural Organization (FAO)/International Atomic Energy Agency (IAEA) 

Agriculture and Biotechnology Laboratory in Seibersdorf, Austria, where research was 

jointly conducted by USDA-APHIS, USDA-ARS, Egypt Plant Protection and Research 

Institute and IAEA personnel (Hallman et al., 2011). After a preliminary study, the cold 

treatment temperature of 1.67°C was maintained and batches of third instar larvae were 

exposed for different lengths of time in oranges. The oranges were dissected after 

treatment and the larvae scored as dead or alive based on their movement. If survivors 

were found the time would be increased and the treatment repeated. No survivors were 

recovered from over 36,000 Bactrocera zonata larvae in oranges held at 1.67°C for 18 

days (Hallman et al., 2012). 

Evaluation: Currently, there is no APHIS approved treatment for Bactrocera zonata.

APHIS approved treatment T107-a is a cold treatment that is required as a condition of 

entry for oranges and other fruits originating from countries infested with Ceratitis 

capitata (Medfly) or C. rosa (Natal fruit fly). T107-a requires that the fruit be prechilled and then kept at 1.11°C for 14 days, at 1.67°C for 16 days, or at 2.22°C for 18 

days. Until PFF was detected in Egypt in 2002, T107-a was the treatment that allowed

importation of Citrus from Egypt. 

At the request of Egypt, CPHST in collaboration with other government agencies 

including USDA ARS, Egypt Plant Protection and Research Institute and IAEA 

personnel, conducted studies in 2011 to determine if the data supported the efficacy of 

T107-a against the PFF as well. The confirmatory test with over 36,000 third instar 

larvae distributed among fruit and kept at 1.67°C resulted in no survivors when the

infested fruit were exposed for 18 days. Compared to this, in another large-scale test, 

when fruit infested with 6000 third instar larvae were exposed for 16 days at 1.67°C, one 

survivor was found. No tests were performed at this temprature in which infested fruit 

were exposed for 17 days. Therefore, while the results strongly supported the requirement 

of 18 days exposure at 1.67°C, results with the 16 days at 1.67°C to confirm the efficacy

of T107-a were not successful for the PFF. Consequently, based on these results, CPHST 

has recommended addition of a new treatment schedule, proposed as T107-l, to the PPQ 

treatment for the PFF. 

Decision: Recommend the addition of a new cold treatment T107-l to treat oranges and 

tangerines for peach fruit fly, Bactrocera zonata (Saunders), to the PPQ treatment 

manual, which would require the exposure of pre-cooled Citrus fruit at 1.67 °C (35 °F) 

for 18 days.

In addition to Bactrocera zonata, Ceratitis capitata (Medfly) is another pest of concern 

in oranges originating from Egypt. But since the proposed T107-l requires refrigeration a 

day or two longer than what is required for Ceratitis capitata or C. rosa (16 days) or for 

Anastrepha species other than A. ludens (17 days) at 1.67 °C, therefore the new treatment 

is also considered adequate to mitigate risks from Ceratitis capitata, C. rosa or

Anastrepha species other than A. ludens.
3

Author:

Inder P.S. Gadh, Ph.D.

Senior Risk Manager-Treatments

USDA APHIS PPQ

Regulations, Permits and Manuals

References Cited:

Hallman, G.J., S.W. Myers, M.F. El-Wakkad, M.D. Tadrous, and A.J. Jessup. 2011. 

Comparison of Cold Tolerance of Bactrocera zonata and Bactrocera invadens

with Ceratitis capitata in Navel Orange: Progress Report and Proposal for Future 

Comparisons of Bactrocera zonata, with Ceratitis capitata and Anastrepha 

ludens. 14 pp.

Hallman, G.J., S.W. Myers, M.F. and G. Taret. 2012. Development of a cold storage 

treatment for peach fruit fly, Bactrocera zonata (Diptera: Tephritidae). 9 pp.

MALR. 2008. Ministry of Agriculture and Land Reclamation (MALR). Letter to Dr. 

Linda Logan, USAID APHIS Attaché, on peach fruit fly technical exchange dated 

March 26, 2008. 

Mohamed, S.M.A and M.F. El-Wakkad. 2009. Cold storage as a disinfestation treatment 

against peach fruit fly, Bactrocera zonata (Saunders), (Diptera: Tephritidae) on 

Valencia orange. Egyptian J. Applied Sci. 24: 290-301.

PPRI. 2006. Plant Protection Research Institute (PPRI). Cold storage of oranges as a 

disinfestations treatment against the peach fruit fly, Bactrocera zonata (Saunders) 

(Diptera: Tephritidae) in Egypt. 9 Aug. 2006. 17 pp. 

USDA. 1969. Decision sheet on entry status of oranges from Egypt. 1 page.

USDA. 2002. Email from APHIS to Egypt NPPO informing Egypt of suspension of 

market access for oranges.