NOTAS TÉCNICAS

Records of Tamarixia radiata (Hymenoptera: Eulophidae) in Northwestern Argentina*

Marcelo J. Lizondo**, Gerardo Gastaminza**, Valmir A. Costa***, Lucrecia Augier**, Mariuxi L. Gómez Torres****, Eduardo Willink** and José R. P. Parra****

* Work supported jointly by Asociación Fitosanitaria del Noroeste Argentino (AFINOA) and EEAOC.
** Sección Zoología Agrícola, EEAOC. ewillink@eeaoc.org.ar.
*** Instituto Biológico, Campinas, São Paulo, Brasil.
**** Universidade de São Paulo, Escola Superior de Agricultura, Departamento de Entomología, Fitopatología e Zoología Agrícola, Piracicaba, São Paulo, Brasil..

Abstract

The presence of Tamarixia radiata Waterston (Hymenoptera: Eulophidae) is reported for the first time in Northwestern Argentina.

Key words: "Huanglongbing"; Greening; Parasitoid; Citrus.

Resumen

Presencia de Tamarixia radiata (Hymenoptera: Eulophidae) en el noroeste argentino
La presencia de Tamarixia radiata Waterston (Hymenoptera: Eulophidae) fue detectada por primera vez en el noroeste argentino.

Palabras clave: "Huanglongbing"; "Greening"; Parasitoide; Cítricos.

Introduction

"Huanglongbing" (HLB), formerly denominated greening, is one of the most important diseases in numerous citrus growing Asian and African countries (Étienne et al., 2001). In America, the disease was first detected in São Paulo, Brazil, in 2004. Its causal agent is a protobacterium found in the phloem of infected plants.
Two insect vectors are responsible for transmitting Huanglongbing, both belonging to the Psyllidae family (Hemiptera): Trioza erytreae (Del Guercio) for Candidatus Liberibacter africanus, and Diaphorina citri Kuwayama for Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus. Recently, D. citri was reported to appear for the first time in Northwestern Argentina (NWA) (Augier et al., 2006).
The integrated management of this pest includes, among other aspects, HLB vector population control through chemical methods, namely insecticide applications. China, for example, reports up to 13 applications per year during flushing period in an area affected by greening disease (Roistacher, 1996). However, chemical control can have harmful side-effects on both enviroment and beneficial fauna.
Tamarixia radiata (Waterston) is a natural enemy of D. citri, an hymenopter eulophid from Northeastern India that has been imported in different countries, such as Taiwan, Reunion Island, Mauritius, and Florida (USA). In Argentina, this insect can be found in the Northeastern region (NEA) regulating psyllid summer population in the province of Corrientes (Cáceres and Aguirre, 2005).
T. radiata develops as an idiobiont ectoparasitoid on D. citri immature stages. The female lays her eggs on the ventral part of the third to the fifth instar nymphs, and the parasitoid larvae feed on the host hemolymph, pupating under the psyllid mummy. The adult then emerges through a hole in the dead nymph thorax (Étienne et al., 2001).
The purpose of this note is to cite for the first time the presence of Tamarixia radiata in Northwestern Argentina. .

Materials and methods

In order to detect the presence of D. citri and its natural enemies in NWA, a survey was carried out in orange, lemon, tangerine, and grapefruit plants in citrus orchards of Jujuy, Salta, Tucumán, and Catamarca, between August 2005 and April 2006. Infested buds were extracted from the plants and taken to the laboratory for further observation under a stereoscopic microscope. Thirteen females and six males of T. radiata were obtained in April 2006, and 23 females and 10 males in May 2006, and the development of the parasitoid was observed until adults were obtained for identification. .

Results

Parasitated nymphs were obtained from orange and tangerine buds in Ledesma (Jujuy) (23º 49´ 08´´ S and 64º 47´ 48.5´´ W), and they were included in the collection of Zoología Agrícola (Estación Experimental Agroindustrial "Obispo Colombres", EEAOC), this being the first reference for Northwestern Argentina.

Cited references

1.Augier, L.; G. Gastaminza; M. Lizondo; M. Argañaraz y E. Willink. 2006. Presencia de Diaphorina citri (Hemiptera: Psyllidae) en el Noroeste Argentino (NOA). Rev. Soc. Entomol. Argent. 65 (3-4): 67-68.
2.Cáceres, S. y M. R. A. Aguirre. 2005. Presencia de Tamarixia radiata (Hymenoptera: Eulophidae), parasitoide del psílido asiático Diaphorina citri (Hemiptera: Psyllidae) en cultivos cítricos de Corrientes. Rev. Soc. Entomol. 64 (4): 348-349.
3.Étienne, J.; S. Quillici; D. Marival and A. Frank. 2001. Biological control of Diaphorina citri (Hemiptera: Psyllidae) in Guadeloupe by imported Tamarixia radiata (Hymenoptera: Eulophidae). Fruits 56: 307-315.
4.Roistacher, C. N. 1996. The economics of living with citrus disease: Huanglongbing (greening) in Thailand. En: Da Graça, J. V.; P. Moreno and R. K. Yokomi (eds.), Proc. Conference of the International Organization of Citrus Virologist (IOCV), 13, University of California, Riverside, USA, pp. 279-285.        [ Links ]         [ Links ]         [ Links ]         [ Links ]