Journal of Insect Science

RESEARCH

First Record of Diaphorina citri (Hemiptera: Psyllidae) in Ecuador Infesting Urban Citrus and Orange Jasmine Trees J.F. Cornejo1 and E.J. Chica1,2 1 Carrera de Ingenierı´a Agrı´cola y Biolo´gica, Escuela Superior Polite´cnica del Litoral, Campus Gustavo Galindo, Km. 30.5 vı´a perimetral, Apartado 09-01-5863, Guayaquil, Ecuador 2 Corresponding author, e-mail: [email protected]

Subject Editor: Todd Shelly J. Insect Sci. 14(298): 2014; DOI: 10.1093/jisesa/ieu160

Key Words: Asian citrus psyllid, citrus, Huanglongbing

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is present in tropical and subtropical regions of Asia, the middle-east and the Americas. The host range of D. citri is limited to several members of the Rutaceae family, including all commercial citrus species (Halbert and Manjunath 2004). In their nymph and adult stages, D. citri alone could be considered only a minor pest of commercial citrus, however, D. citri is a vector for the three bacteria (‘Candidatus Liberibacter asiaticus’, ‘Candidatus Liberibacter americanus’, and ‘Candidatus Liberibacter africanus’) that cause the devastating Huanglongbing (HLB) disease in citrus (Bove´ 2006). Currently, HLB is the most serious threat to citriculture worldwide, and because there is no known cure for HLB, control of the disease spread is mostly conducted through controlling D. citri populations and using certified pathogen-free planting material. In America, D. citri is present in the southern United States (USDA 2010), the Caribbean basin and central Ame´rica (Burckhardt and Martı´nez 1989, Halbert and Nu´n˜ez 2004, Villalobos et al. 2005), most of the countries in the Atlantic and Caribbean coast of South America (Da Costa Lima 1942, Cermeli et al. 2000, Augier et al. 2006) and the Andean region of Colombia (ICA 2012). Neither HLB or D. citri have been reported in the Pacific coastal plains of South America where most of the commercial citrus production of Ecuador, Peru, and Chile is located.

Psyllids were found in high numbers in the conurbation formed by the cities of Guayaquil, Samborondo´n, and Dura´n. No psyllids were found in the main citrus producing regions of Ecuador located in western slopes of the Andes and the Portoviejo, and Chone cantons (Fig. 1). The first finding of D. citri occurred on 20 January 2013, when numerous adults and nymphs were found in a M. exotica tree growing along a sidewalk in Guayaquil (2 100 28.1600 S, 79 530 54.3100 W). After this finding, Agrocalidad, the national plant protection and quarantine authority was alerted to confirm the identity of the psyllids. As of November 2013, the range of D. citri remained restricted to the Guayaquil-Samborondo´n-Dura´n conurbation without change in the level of infestation within the city. The identity of the collected specimens was confirmed to be D. citri by Agrocalidad, originally determined by Dr. Susan Halbert, Florida Department of Agriculture and Consumer Services, Gainesville, FL, USA (Florida State Collection of Arthropods number E2013-882). In Guayaquil, Samborondo´n and Dura´n, D. citri was distributed widely with adults present in 61 out of the 80 trees sampled on these locations. The number of adults per tree ranged from 7 to more than 50 (Fig. 2). Both leaves and psyllids tested negative for HLB-causing bacteria by PCR.

Materials and Methods

Discussion

A survey for HLB symptoms and D. citri was conducted from July 2012 to May 2013 in the coastal plains of Ecuador. In total, 26 locations were visited. These locations were cities, towns, and citrus farms located in the outskirts of these cities/towns. Psyllids were sampled striking a branch (four branches per tree) of citrus (Citrus spp., Sapindales: Rutaceae) or orange jasmine (Murraya exotica [L.] Jack, Sapindales: Rutaceae) trees over a white sheet of paper and examining whether adults or nymphs fell from the struck branch. About 1,500 citrus/orange jasmine trees from the 26 locations were sampled during the survey. When psyllids were found, a sample of at least 25 psyllids was collected using a brush and conserved in ethanol. The collected psyllids and leaves from all locations were tested for HLB-causing bacteria by polymerase chain reaction (PCR) as in Li et al. (2007).

We report for the first time the presence of D. citri in Ecuador. D. citri is a vector for the bacteria that cause HLB disease in citrus, currently a major threat for worldwide citriculture. D. citri was found only in the conurbation formed by the cities of Guayaquil, Samborondo´n, and Dura´n in ornamental and domestic citrus and orange jasmine trees. The absence of psyllids in citrus producing areas 80–120 km away from these cities as well as in the city of Milagro (  30 km northeast), where orange jasmine is grown commercially, suggests that D. citri was introduced to Guayaquil. The widespread distribution of D. citri in Guayaquil-Samborondo´n-Dura´n and the relatively sparse distribution of potential D. citri hosts within these cities suggest that the dispersal of the psyllids within these cities was aided by human movement of host plants and/or transporting of municipal pruning debris from parks and

Results

C The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America. V

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ABSTRACT. Adults and nymphs of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), were collected in the Guayaquil, Samborondo´n, and Dura´n cantons in coastal Ecuador. Psyllids were found in high numbers in citrus (Citrus spp., Sapindales: Rutaceae) and orange jasmine (Murraya exotica [L.] Jack, Sapindales: Rutaceae) trees within the Guayaquil-Samborondon-Duran conurbation; however, none was found during scoutings in the main citrus producing areas in coastal Ecuador. To the best of our knowledge, this is the first report of D. citri in Ecuador and the Pacific coastal plain of South America.

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this rate was about three times faster (Halbert et al. 2008), suggesting that areas where M. exotica and citrus are commercially grown in Ecuador could be reached by D. citri in a relatively short time. Due to climatic conditions, irregular year-round flushing and deficient crop management practices, D. citri could become established and thrive in the citrus producing regions of Ecuador, increasing the risk of a rapid dissemination of HLB if infected material reaches the country. The presence of D. citri in the Guayaquil area also poses a threat for the Peruvian lemon and lime industries located in Northern Peru near the border with Ecuador, about 260 km south of Guayaquil. Continuous monitoring of populations and surveying are currently being conducted in Guayaquil-Samborondo´n-Dura´n and the main citrus producing regions.

Acknowledgments We thank Imelda Fe´lix (Agrocalidad) for key exchanges of ideas during our survey and Marı´a Fernanda Ratti (CIBE) for her technical assistance during the PCR tests. We also thank Agrocalidad for their collaboration in the identification of the specimens collected and Centro de Investigaciones Biotecnolo´gicas del Ecuador (CIBE) at the Escuela Superior Polite´cnica del Litoral for its contribution to conduct the PCR tests.

Fig. 2. Histogram of the number of adult psyllids per tree in citrus and Murraya exotica trees sampled in the Guayaquil-Samborondo´nDura´n conurbation between January and May 2013.

Reference Cited

medians. One year after the first finding of D. citri in Guayaquil, its distribution remained restricted to the Guayaquil-Samborondo´n-Dura´n conurbation. In Brazil, the range of D. citri increased at a rate of approximately 20 km per year (Gottwald et al. 2007), whereas in Florida

Augier, L., G. Gastaminza, M. Lizondo, M. Argan˜araz, and E. Willink. 2006. Presencia de Diaphorina citri (Hemiptera: Psyllidae) en el Noroeste Argentino (NOA). Revista de la Sociedad Entomolo´gica Argentina 65: 67–68. Bove´, J. M. 2006. Huanglongbing: A destructive, newly-emerging, century-old disease of citrus. J. Plant Pathol. 88: 7–37.

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Fig. 1. Distribution of Diaphorina citri in coastal Ecuador (July 2012 to May 2013). Circles represent the localities surveyed, gray circles mark places were Diaphorina citri adults were collected. Shaded areas represent the major citrus producing cantons in Ecuador.

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CORNEJO AND CHICA: FIRST RECORD OF DIAPHORINA CITRI IN ECUADOR

Burckhardt, D., and M. Martinez. 1989. Note sur la pre´sence su Honduras d’un redoutable ennemi de`s citrus: Diaphorina citri Kuwayama [Hom. Psylloidea Psyllidae]. Bull. Soc. Entomol. France 94: 65–66. Cermeli, M., P. Morales, and F. Godoy. 2000. Presencia del psı´lido asia´tico de los cı´tricos Diaphorina citri Kuwayama (Hemiptera: Psyllidae) en Venezuela. Bol. Entomol. Venez. 15: 235–243. Da Costa Lima, A. M. 1942. Insetos do Brazil: Homopteros. Escola Nacional de Agronomı´a, Officinas de Obras do Jornal do Comercio, Rio de Janeiro, Brasil. Gottwald, T. R., J. V. Da Grac¸a, and R. B. Bassanezi. 2007. Citrus huanglongbing: the pathogen and its impact. Plant Health Prog. Published online, doi: 10.1094/PHP-2007-0906-01-RV (accessed 31 October 2014). Halbert, S. E., and C. A. Nu´n˜ez. 2004. Distribution of the Asian citrus psyllid, Diaphorina citri Kuwayama (Rhynchota: Psyllidae) in the Caribbean basin. Fla. Entomol. 87: 401–402. Halbert, S. E., and K. L. Manjunath. 2004. Asian citrus psyllids (Sternorrhyncha: Psyllidae) and greening disease of citrus: a literature review and assessment of risk in Florida. Fla. Entomol. 87: 330–353. Halbert, S. E., K. L. Manjunath, and M. W. Brodie. 2008. Large-scale distribution of Diaphorina citri Kuwayama and citrus huanglongbing in Florida.

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Proceedings International. Research Conference on Huanglongbing. Plant Management Network, December 2008, Orlando. (http://www.plantmanage mentnetwork.org/proceedings/irchlb/2008/presentations/IRCHLB.2.6.pdf) (accessed 31 October 2014). ICA. 2012. Vigilancia oficial del psı´lido asia´tico de los cı´tricos, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) en Colombia. (http://www.ica.gov. co/Areas/Agricola/Servicios/Epidemiologia-agricola/HUANGLONGBING/ BOL_HLB_DIC_21_2012.aspx) (accessed 31 October 2014). Li, W., J. S. Hartung, and L. Levy. 2007. Evaluation of DNA amplification methods for improved detection of “Candidatus Liberibacter Species” associated with Citrus Huanglongbing. Plant Dis. 91: 51–58. USDA. 2010. National Quarantine: Citrus Greening and Asian Citrus Psyllid. Plant Health (http://www.aphis.usda.gov/plant_health/plant_pest_info/cit rus_greening/downloads/pdf_files/nationalquarantinemap.pdf) (accessed 31 October 2014). Villalobos, W., D. Hollis, C. Godoy-Cabrera, and C. Rivera-Herrero. 2005. Primer informe de Diaphorina citri (Hemiptera: Psyllidae) en Costa Rica. Insecta Mundi. 19:191–192. Received 27 January 2014; accepted 29 August 2014.

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First record of Diaphorina citri (Hemiptera: Psyllidae) in Ecuador infesting urban citrus and orange jasmine trees.

Adults and nymphs of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), were collected in the Guayaquil, Samborondón, and Dur...
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