Vietnam: Longan pest management

The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact [email protected] Pest Management of Longan (Sapindales: Sapindaceae) in VietnamHanh Tr a n,1 Hoa Nguyen Va n,1 Rangaswamy Muniappan,2,7 James Amrine,3Rayapati Naidu,4 Robert Gilbertson,5 and Jaspreet Sidhu61Plant Protection Division, Southern Horticultural Research Institute, Box 203, My Tho city, Tien Giang, Vietnam, 2Integrated Pest Management Innovation Lab, Virginia Tech, 526 Prices Fork Road, Blacksburg, VA 24061, 3Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV 26506, 4Department of Plant Pathology, Irrigated Agriculture Research & Extension Center, Washington State University, Prosser, WA 99350, 5Department of Plant Pathology, University of California, Davis, CA 95616, 6Uni-versity of California Cooperative Extension, 1031 S Mount Vernon Ave, Bakersfield, CA 93307, and 7Corresponding author, e-mail: [email protected]

Subject Editor: Tom RoyerReceived 17 January 2019; Editorial decision 29 April 2019

Abstract

This paper describes the current state of pests and diseases of longan (Dimocarpus longan Lour.) and their management in Vietnam. Longan is the third most cultivated fruit crop and second major fruit crop exported from Vietnam. Brief descriptions of arthropod pests Eriophyes dimocarpi Kuang (Acari: Eriophyidae), Conogethes punctiferalis Guenée (Lepidoptera: Crambidae), Conopomorpha sinensis Bradley (Lepidoptera: Gracillariidae), Conopomorpha litchiella Bradley (Lepidoptera: Gracillariidae), Tessaratoma papillosa Drury (Hemiptera: Tessaratomidae), Eudocima phalonia L. comb. (Lepidoptera: Erebidae), oriental fruit fly Bactrocera dorsalisHendel (Diptera: Tephretidae), Planococcus lilacinus Cockerell (Hemiptera: Pseudococcidae), Drepanococcus chitonGreen (Hemiptera: Coccidae), and Cornegenapsylla sinica Yang & Li (Hemiptera: Psyllidae) and fungal diseases Phytophthora palmivora Butler (Peronosporales: Peronosporaceae), Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (Incertaesedis: Glomerellaceae), and Ceratocystis fimbriata Ellis & Halsted (Microascales: Ceratocystidaceae) affecting longan are given. The longan witches’ broom syndrome is a major factor causing 50–86% annual crop loss in Vietnam and it has been considered the primary constraint in production. The causative agent of this syndrome has been identified as the eriophyid mite E. dimocarpi. Deployment of Integrated Pest Management strategies for longan production in Vietnam is outlined.Key words: longan IPM, witches’ broom, VietnamTropical fruits make a significant contribution to the economy of Vietnam and nearly half of them are produced in the Mekong Delta region. This region is an important economic center supporting over 15 million people and contributing over 27% of Vietnam’s national GDP. The longan [(Dimocarpus longan Lour. (Sapindaceae)] is a per-ennial fruit tree (Waite and Hwang 2002) (Fig. 1). China, Thailand, and Vietnam are major producers of longan. It is cultivated mostly in Vinh Long, Tien Giang, and Ba Ria-Vung Tau provinces of southern Vietnam. In 2016, longan was planted over an area of 73,600 ha in Vietnam and it is the third most cultivated fruit crop after mango and banana, and the second most exported crop behind dragon fruit (Department of Crop Production 2017).The export value of longan in Vietnam was $62.13 million in 2017. Fresh longan has been exported to the U.S. and European Union markets with an increasing volume in the last 4 yr, with ex-port potential still to increase. The trees begin production 2 to 3 yr after planting. Normal flower initiation occurs in late winter and flowers open in early spring (Waite and Hwang 2002) (Fig. 2). However, many farmers in Vietnam induce flowers at different times of the year by ringing the stems and applying potassium chlorate to the soil, which enables them to harvest fruits throughout the year. Pruning is done every year after harvest to maintain suitable height and for pest and disease management

Pests and Diseases

Pests of longan are known to cause 50 to 100% crop losses un-less timely interventions are implemented (Department of Plant Protection 2015). Arthropod pests that attack longan and their natural enemies in different countries have been reviewed by Waite and Hwang (2002). The major pests of longan in Vietnam are Eriophyes dimocarpi (Kuang) (Acari: Eriophyidae), Conogethes Journal of Integrated Pest Management, (2017) 10(1): 18; 1–10do