First record of Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) in Misiones province, Argentina

Abstract

Citrus greening or Huanglongbing (HLB) is considered the world's most destructive citrus disease (Bové, 2006). In Argentina, HLB was detected for the first time in Misiones in 2012 in a tangerine tree (Agostini et al., 2015). HLB is associated with an unculturable α-proteobacterium, 'Candidatus Liberibacter' and is transmitted by two psyllid vectors, Diaphorina citri Kuwayama (Hemiptera: Liviidae) and Trioza erytreae (Del Guercio) (Hemiptera: Triozidae). D. citri was reported to appear for the first time in Northwestern Argentina (Augier et al., 2006). To date, chemical control has been the basis of D. citri management programs, but this strategy strongly relies upon frequent applications of a few chemical insecticides throughout the crop season (Yamamoto et al., 2009). Because of this intensive use of pesticides, new control strategies for the vector are being sought, such as biological control. Biological control of D. citri can be accomplished using the parasitoid Tamarixia radiata Waterston, 1922 (Hymenoptera: Eulophidae), which is the most effective natural enemy. The idiobiont ectoparasitoid T. radiata is native to northern India, where it develops on D. citri nymphs, preferentially those in the 3 rd to 5 th instars (Etienne et al., 2001), and is considered a specialist parasitoid (Zuparko et al., 2011). The female T. radiata also kills its host by feeding, and one female can cause the death of up to 500 nymphs from feeding and parasitism (Hoy and Nguyen, 2001). Considering the importance of citrus crops in Argentina and the biological control of D. citri as an alternative management, the present note reports for the first time the presence of T. radiata in the province of Misiones. The search of D. citri and its biological controller T. radiata was carried out in Misiones between September 2016 and December 2017. Field collections were conducted in orchards planted with Citrus spp. from different locations and trees of orange jessamine, Murraya paniculata (L.) Jack (Rutaceae) in urban areas. In nine orchards planted with Citrus spp. (less than 4 ha. each) were installed yellow sticky traps (12.5 x 10 cm). One trap at each cardinal point and one in the center of the grove were placed, as suggested by Robles García (2012). Also, yellow sticky traps were located in M. paniculata distributed in urban areas. The traps suspend from 1.5 m above the ground were deployed and retrieved from the same trees every two