1 **United States Department of Agriculture Animal and Plant Health Inspection Service**  **Plant Protection and Quarantine**



# Importation of Litchi (

**Litchi chinensis Sonn.) and**  **Longan (**  **Dimocarpus longan Lour.) fruits from**  **Vietnam into the Continental Unit ed States** 

**Risk Management Document**

August 1 8 , 2011

**United States Department of Agriculture Animal and Plant Health Inspection Service**  **Agency Contact: claudia.ferguson@aphis.usda.gov** 2

**I.** 

### Executive Summary:
The National Plant Protection Organization (NPPO) of Vietnam requested market access to export fresh litchi (

Litchi chinensis ) and longan ( Dimocarpus longan ) fruits to the continental United States. These fruits have not been exported from Vietnam to the United States before, so Vietn am provided detailed information on pests associated with this commodity in that country

. Vietnam further proposed to treat the fruit with an APHI S approved generic irradiation treatment that would mitigate risks from most insect pests. Based on the pest information received and that the fruit would receive an APHI S approved irradiation treatment, APHI S determined that a pest list identifying all quarantine insect pests in Vietnam would be sufficient information to evaluate pathway risks from insects and that further assessment for the insect pest s was not needed

. This approach would also meet one of APHI S’ objectives behind the development of a generic irradiation treatment for most insect pests.
APHI S’s Center for Plant Health Science and Technology (CPHST) developed a pest risk assessment (PRA) for litchi, longan and rambutan, originating from member countries of the ASEAN region comprising: Brunei, Cambodia, Indonesia, L aos, Malay sia, the Philippines, Thailand, and Vietnam (USDA, 20 11 ). CPHST ident ified the quarantine pests that are likely to follow the pathway

for these three commodities from each country . The PRA further analy ze s the pathway risks from non

- insect pests i.e. the pests that are not targeted by the irradiation treatment, and recomme nd s measures that might be needed to mitigate risks from these non

insect pests. The PRA w as based on (1) the information provided by member countries of the region, (2) published scientific literature and (3) pest interception records of the United Stat es Department of Agriculture (Pest I D, 2009). Analy sis of the pest lists for litchis and longans from Vietnam indicated that most pests likely to follow the pathway

are insect pests and would be effectively neutralized 1 with the irradiation generic dos e of 400 Gy

(USDA, 2006). Li tchis and longans may also potentially

serve as a pathway for a mite Aceria litchii and litchis may also serve as a pathway

for a fungus, Phytophthora litchii

. Both Aceria litchii and Phytophthora litchii are rated to have a **medium** risk potential. Since irradiation is not an approved treatment for these pests, additional measures would be needed to mitigate their pathway risk s
. This risk management document outlines the phy tosanitary measures that APHI S will require for the importation of litchis and longans from Vietnam and documents the evidence used by APHI S to conclude that these measures will effectively prevent the introduction of quarantine pests into the continental United States.

1 A pest is considered neutralized when it is killed, rendered sterile or its further development into becoming an adult is stopp ed.3

**II.** 

### Commodity wise analysis **of quarantine pests and mitigation measures required** 
**1. Litchis** 
**A. Introduction** 
The PRA completed by

CPHST identified 16 quarantine pests that could potentially follow the pathway of litchi fruit from Vietnam (USDA, 20 11 ; Table 1). These include 14 insect pests, one mite and one fungus as follows:
**Table 1.** Quarantine pests likely to follow the pathway

of fresh litchi fruit imported from Vietnam into the continental United States.

**B. Risk Management Measures** 
AP HI S proposes to allow the importation of the fresh litchi fruit from Vietnam into the continental United States (except Florida) under the following conditions: (a) The fruit must be commercially produced and be part of a commercial consignment as defined in 7 CFR Section 319.56

- 2. The fruit must be grown in orchards registered with and monitored by

the NPPO of Vietnam to ensure that fruits are produced free of disease caused by Phytophthora litchii

. **Arthropods** Acari: Eriophyidae Aceria litchii (Keifer) Diptera: Tephritid ae Bactrocera cucurbitae (Coquillett) Bactrocera dorsalis (Hendel) Hemiptera: Coccidae Ceroplastes rubens Maskell Coccus viridis (Green) Hemiptera: Pseudococcidae Dysmicoccus neobrevipes Beardsley Nipaecoccus viridis (Newstead) Paracoccus interc eptus Lit Planococcus lilacinus (Cockerell) Planococcus litchi Cox Planococcus minor (Maskell) Pseudococcus cryptus Hempel Lepidoptera: Gelechiidae Conopomorpha sinensis Bradley Lepidoptera: Pyralidae Conogethes punctiferalis (Guenée) Lepido ptera: Tortricidae Cryptophlebia ombrodelta (Lower) **Fungi** Oomycetes: Pythiales Phy to ph thora litchii (C.C. Chen ex W.H. Ko, H.S. Chang, H.J. Su, C.C. Chen & L.S. Leu) Voglmayr, Göker, Riethm. & Oberw4

(b) The cartons containing the fruit must be stamped “Not for importation into or distribution in FL”. (c) The fruit must be irradiated with a minimum absorbed dose of 400 Gy and follow the requirements of 7CFR parts 305 and 319. (d) Prior to departure from Vietnam:

 If irradiation is applied outside the United States, eac h consignment of fruit must be inspected jointly

by APHI S and Vietnam inspectors. Using a sampling procedure mutually agreed upon by

APHI S and the NPPO, a representative sample of fruit must be drawn from each lot, inspected and found free from the fungu s, Phytophthora litchii. A Phy tosanitary Certificate (PC) issued by the NPPO of Vietnam must accompany each consignment certifying that the fruit received the required irradiation treatment with 400 Gy as the minimum absorbed dose. The PC must also inclu de an AD that the consignment was inspected by the Vietnam inspectors and found free from Phytophthora litchii.
 If irradiation is to be applied upon arrival in the United States, each consignment of fruit must be inspected by

Vietnam inspectors. Using a sampling procedure mutually agreed upon by APHI S and the NPPO, a representative sample of fruit must be drawn from each lot, inspected and found free from the fungus, Phytophthora litchii. A Phy tosanitary Certificate (PC) issued by the NPPO of Vietnam mu st accompany each consignment with an Additional Declaration (AD) that the consignment was inspected by the Vietnam inspectors and found free from Phytophthora litchii. (e) Each consignment is subject to inspection at the U.S. ports

- of

- entry

.

**C. Evidence f**

**or the Effective Removal of Pests of Concern from the Pathway** (i) Insect Pests: Fourteen of the sixteen pests likely to follow the litchi pathway are insect pests. A minimum abosorbed dose of 400 Gy has been determined by

APHI S regulations 7CFR305.9 t o be adequate to neutralize al l insect pests excludi n g adults and pupae in the order L epidoptera. Of the fourteen insect pests likely

to follow the pathway , three belong to the order Lepidoptera (Table 1). Although the generic irradiation treatment is n ot approved for Lepidopteran pupae and adults, those life stages are unlikely to be associated with the commodity . Due to their mobility , free

living adults of L epidoptera are unlikely to be in the pathway

of commercially

produced litchi fruits. As for the pupal stage, in most of the genera of concern ( Conogethes, Conopomorpha, Cryptophlebia ), the pupae are either associated with plant parts other than fruit or they occur externally on their host’s plant parts (CABI , 2007; Hwang and Hsieh, 1989; I PM DANI DA, 2003; Nair, 1975; Ooi et al., 2002; Underhill, 1943; van der Berg et al., 2001). Or, if the pupae occur inside the fruit or seed of their host plants, they would be associated with premature fruit drop and/or obvious damage and sy mptoms ( CABI , 2007; Gupta et al., 2005; Singh et al., 2002; Waite and Hwang, 2002 ), thereby making it likely

for the fruit to be culled during standard harvest or post

- harvest handling and processing. Also, except for two interceptions of Conopomorpha in permit cargo with litchi fruit, inspectors at U.S. por ts

- of

- entry have never intercepted pupae of the other Lepidoptera genera of concern associated with commercial fruit5

shipments of any

ty pe of fruit ( PestI D, 2009 ). This lack of interception is evidence of the low likelihood of any

of the L epidoptera pupae followi ng the pathway of commercial fruit. The irradiation treatment, along with standard postharvest processes, therefore, will likely mitigate the risks from all the insects listed above. (ii) Mites: The litchi mite, Aceria litchii , is found associated wi th litchi and longan only (USDA, 2007). The mite is primarily

a pest of foliage and flower parts but is also sometime associated with the fruit. In severe cases, flowers may be completely

destroy ed and setting of fruit is prevented or the set fruit may

be damaged cosmetically (Waite, 1999). Mites are external pests on the fruit, and because of the damage it causes on fruits, inspection and culling of the damaged fruit are considered effective in mitigating risk from such pests. Although it is unlikely th at commercially produced fruit is a pathway for the mite, because of its small size, shipments should be prohibited into Florida, where litchis are grown, as an added precaution. This is consistent with other import programs where shipments of litchis and/ or longans are prohibited into Florida for the same pest. Shipments of litchi and/or longans from China, India, Thailand and Hawaii into the mainland U.S. with inspection for the pest over the past few y ears show no record of interception. (iii) Fungi: Commercial litchi production areas where Phytophthora litchii is present and active will require fungicidal field treatments to reduce fruit drop. Having NPPO of Vietnam monitor fields where litchi is produced for export will ensure application of disease control measures. In nature the disease is confined to a single host (litchi), although under laboratory conditions, tomatoes, papay as and loofah (

Luffa cylindrical) may

also be infected (CABI , 2003). Most infected litchi fruit will be culled because tr ained harvesters, packinghouse personnel, and plant quarantine inspectors can easily

detect the distinctive signs of the disease on fruit. Infected, non

sy mptomatic fruit may

go undetected, but the likelihood of introduction via the few fruit that may esc ape detection is very

low. I t is highly

unlikely that market fruit will be in a situation to introduce the disease because free water is required for the spores to infect a host. Additionally , there is no record of interception of this disease on litchis imported into the U.S. from other countries in regions where this pathogen is present. Therefore no measures are recommended for this pathogen beyond certification for freedom based on inspection (USDA 2007). As part of the U.S. requirements (7 CFR 305. 9) governing the use of irradiation as a phy tosanitary treatment, APHI S and the NPPO of Vietnam must jointly develop an operational work plan (OWP). The work plan shall include details of activities including inspection of articles that NPPO must perform before the treatment or departure. Inspection of the fruit and freedom from pests not targeted by irradiation as declared on the PC will ensure that all pests of concern are removed from the pathway

.6

**2. Longan** 
**A. Introduction** 
The PRA completed by

CPH ST identified 17 quarantine pests that could follow the pathway of longan fruit from Vietnam (USDA, 20 11 ; Table 2). All but one pest, a mite, are insect pests.
**Table 2.** Quarantine pests identified as likely to follow the pathway

of fresh longan fruit imp orted from Vietnam into the continental United States

**Arthropods** Acari: Eriophyidae Aceria litchii (Keifer) Diptera: Tephritidae Bactrocera dorsalis (Hendel) Hemiptera: Coccidae Ceroplastes rubens Maskell Coccus viridis (Green) Drepanococcus c hiton (Green) Hemiptera: Pseudococcidae Dysmicoccus neobrevipes Beardsley Exallomochlus hispidus (Morrison) Maconellicoccus hirsutus (Green) Nipaecoccus viridis (Newstead) Paracoccus interceptus Lit Planococcus lilacinus (Cockerell) Planoc occus litchi Cox Planococcus minor (Maskell) Pseudococcus cryptus Hempel Lepidoptera: Gelechiidae Conopomorpha sinensis Bradley Lepidoptera: Pyralidae Conogethes punctiferalis (Guenée) Lepidoptera: Tortricidae Cryptophlebia ombrodelta (Lower)
**B. Risk Management Measures** 
APHI S proposes to allow the importation of the fresh longan fruit from Vietnam into the continental United States (except Florida) under the following conditions: (a) The fruit must be commercially produced and be part of a comme rcial consignment as defined in 7 CFR Section 319.56

- 2. (b) The cartons containing the fruit must be stamped “Not for importation into or distribution in FL”. (c) The fruit must be irradiated with a minimum absorbed dose of 400 Gy and follow the requirements of 7CFR parts 305 and 319. (d) Prior to departure from Vietnam:

 If irradiation is applied outside the United States, each consignment of fruit must be inspected jointly

by APHI S and Vietnam inspectors and accompanied by a Phy tosanitary7

Certificate (PC) issued b y the NPPO of Vietnam certifying that the fruit received the required irradiation treatment with 400 Gy as the minimum absorbed dose.

 If irradiation is to be applied upon arrival in the United States, each consignment of fruit must be inspected by

Vietn am inspectors and accompanied by a Phy tosanitary Certificate (PC) issued by

the NPPO of Vietnam. (e) Each consignment is subject to inspection at the U.S. ports

- of

- entry

. **C. Evidence for the Effective Removal of Pests of Concern from the Pathway** (i) Inse ct Pests: Sixteen of the seventeen pests likely to follow the longan pathway are insect pests. A minimum absorbed dose of 400 Gy has been determined by

APHI S regulations 7CFR305.9 to be adequate to neutralize all insect pests excluding adults and pupa e in the order Lepidoptera. Of the sixteen insect pests likely to follow the pathway , three belong to the order Lepidoptera (Table 2). Although the generic irradiation treatment is not approved for Lepidoptera pupae and adults, those life stages are unl ikely to be associated with the commodity here. Due to their mobility , free

- living adults of L epidoptera are unlikely to be in the pathway

of commercially produced longan fruits. As for the pupal stage, the pupae in the three genera of concern ( Conogethes, Conopomorpha, and Cryptophlebia ), are either associated with plant parts other than fruit or they

occur externally

on their host’s plant parts (CABI , 2007; Hwang and Hsieh, 1989; I PM DANI DA, 2003; Nair, 1975; Ooi et al., 2002; Underhill, 1943; van der Ber g et al., 2001). Or, if the pupae occur inside the fruit or seed of their host plants, they would be associated with premature fruit drop and/or obvious damage and sy mptoms ( CABI , 2007; Gupta et al., 2005; Singh et al., 2002; Waite and Hwang, 2002 ), thereby making it likely

for the f ruit to be culled during standard harvest or post

- harvest handling and processing. Except for two interceptions of Conopomorpha in permit cargo with litchi fruit, inspectors at U.S. ports

- of

- entry have never intercepted pupae of the other Lepidoptera gener a of concern associated with commercial fruit shipments (of any ty pe of fruit) ( PestI D, 2009 ). This lack of interception is evidence of the low likelihood of any of the L epidoptera pupae following the pathway of commercial fruit. The irradiation treatment, along with standard postharvest processes, therefore, will likely

mitigate the risks from all the insects listed above. (ii) Mites: As explained under litchis, the litchi mite, Aceria litchii , is found associated with litchi and longan only

(USDA, 2007). The mite is primarily a pest of foliage and flower parts but is also sometimes associated with the fruit. In severe cases, flowers may be completely

destroy ed and setting of fruit is prevented or the set fruit may be damaged cosmetically (Waite, 1999). Mites feed externally

on the fruit and because of the damage mites causes on fruits, inspection and culling of the damaged fruit are considered effective in mitigating risk from such pests. Although it is unlikely

that commercially

produced fruit is a pathway for the mite, because of its small size, shipments should be prohibited into Florida, where litchis are grown, as an added precaution. This is consistent with other import programs where shipments of litchis and/or longans are prohibited into Florida for the same pest. Shipments of litchi and/or longans from8

China, India, Thailand and Hawaii into the mainland U.S. with inspection for the pest over the past few y ears show no record of interception. As part of the U.S. requirements (7CFR305.9) governi ng the use of irradiation as a phy tosanitary treatment, APHI S and the NPPO of Vietnam must jointly develop an operational work plan (OWP). The work plan shall include details of activities including inspection of articles that NPPO must perform before the treatment or departure. Phy tosanitary inspection of the fruit will ensure that all pests of concern not targeted by irradiation are removed from the pathway

. 

### III. Conclusion The phy tosanitary requirements described above include treatment of litchi and longan fruit from Vietnam with irradiation using a minimum absorbed dose of 400 Gy and phy tosanitary inspections for pests not targeted by the irradiation treatment. The risk management document concludes that based on the evaluation of effectiveness of these measures directed against the pests of concern, APHI S finds that the safeguards of 7 CFR § 319.56 and the additional mitigations described here will result in the effective removal of the pests of concern identified by the PRA for the importation of fresh litchis and longans from Vietnam into the Continental United States.



### IV. Authors:

In der Paul S. Gadh, Ph.D. Senior Risk Manager

– Treatments



### V. References:
CABI . 2003. Crop Protection Compendium. Commonwealth Agricultural Bureau I nternationa l (CABI ), Wallingford, UK. CABI . 2007. Crop Protection Compendium. Centre for Agriculture and Biosciences International (formerly Commonwealth Agricultural Bureau International) (CABI ), Wallingford, UK. Gupta, H. C. L ., O. P. Ameta, and V. K. Chechani. 200 5. Management of insect pests of horticultural crops. Agrotech Publishing Academy , Udaipur. 224 pp. Hwang, J. S., and F. K. Hsieh. 1989. The bionomics of the cocoa pod borer, Conopomorpha cramerella (Snellen), in Taiwan. Plant Protection Bulletin Taipei 31 (4):387

- 395. IP M DANI DA. 2003. Durian fruit borer. I PM Thailand. L ast accessed March 10, 2006, http://www.ipmthailand.org/EN/Pests/Durian_fruit_borer.htm

. Nair, M. R. G. K. 1975. Insects and mites of crops in India. Indian Council of Agricultural Research New Delhi. 404 pp. Ooi, P. A. C., A. Winotai, and J. E. Peña. 2002. Pests of minor tropical fruits. Pages 315

- 330 in J. E. Peña, J. L . Sharp, and M. Wy soki, (eds.). Tropical fruit pests and pollinators: biology , economic importance, natural enemies and control. CAB International, Wallingford, U.K.9

PestI D. 2009. Pest I dentification Database (PestI D). United States Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine. https://mokcs14.aphis.usda.gov/aqas/login.jsp. (Archived at PERAL ). Singh, Y. P., G. K. Singh, and K. Suresh. 2002. Occurrence of Dichocrocis punctiferalis Guen. (Lepidoptera: Py

ralidae) on mango in Western U.P. Progressiv e Horticulture 34(1):130. Underhill, G. W. 1943. Some insect pests of ornamental plants [Abstract]. Virginia Agric Expt Sta Bull 349:1

- 38. USDA. 2006. USDA Treatments for Fruits and Vegetables. January 27, 2006 issue of Federal Register 71(18): 4451

- 4464. USDA. 2007. Pest lists for fresh Litchi chinensis (ly chee or litchi), Dimocarpus longan (longan), Mangifera indica (mango), Garcinia mangostana L. (mangosteen), Nephelium lappaceum L. (rambutan), and Ananas comosus (pineapple) fruit from Thailand, US Dep artment of Agriculture, Animal & Plant Health Inspection Service, Plant Protection & Quarantine, Center for Plant Health Science & Technology , NC . USDA. 2011

. Importation of Fresh Fruit of L itchi ( Litchi chinensis ) , L ongan ( Dimocarpus longan ), and R ambutan (

Nephelium lappaceum ) into the C ontinental Uni ted States from ASEAN C ountries

- A Qualitative, Pathway

- initiated Pest Risk Assessment. USDA, APHI S, CPHST, 107 pp. van den Berg, M. A., E. A. de Villiers, and P. H. Joubert. 2001. Pests and beneficial arthropods of tropical and non

- citrus subtropical crops in South Africa. Institute for Tropical and Subtropical Crops, Nelspruit, South Africa. 525 pp. Waite, G. K. 1999. New evidence further incrimates honey bees as v ectors of lychee erinose mite Aceria litchi (Acari: Eriophiidae). Experimental and Applied Acarology 23(2): 145

- 147. Waite, G. K., and J. S. Hwang. 2002. Pests of litchi and longan. Pages 331

- 359 in J. E. Peña, J. L. Sharp, and M. Wy soki, (eds.). Tropical fruit pests and pollinators: biology , economic importance, natural enemies and control. CABI Publishing, Wallingford, UK.