ECOLOGY, BEHAVIOR AND BIONOMICS Haplaxius crudus (Hemiptera: Cixiidae) Transmits the Lethal Yellowing Phytoplasmas, 16SrIV, to Pritchardia pacifica Seem. & H.Wendl (Arecaceae) in Yucatan, Mexico JDZIDO 1 ,RSÁNCHEZ 2 ,MDOLLET 1,3 ,JJULIA 1 ,MNARVAEZ 2 ,SFABRE 1 ,COROPEZA 2 1 Cirad, UMR IPME, Montpellier, France 2 Centro de Investigación Científica de Yucatán (CICY), Mérida, Mexico 3 Embrapa CENARGEN, Brasília DF, Brasil Abstract Keywords “In-mass introduction of insects”, vector, transmission, 16SrIV-A, 16SrIV-D Correspondence M Dollet, Embrapa CENARGEN, Brasília DF, Brasil; dolletm.palm@gmail.com Edited by Denise Návia – Embrapa Received 18 January 2020 and accepted 22 June 2020 * Sociedade Entomológica do Brasil 2020 Lethal yellowing (LY) affects several palm species in the Americas. It is caused by 16SrIV group phytoplasmas. In Florida (USA), LY was shown to be transmitted by the planthopper Haplaxius crudus (Van Duzee) (Hemiptera, Cixiidae) to different palm species, including Pritchardia pacifica Seem.& H. Wendl. (Arecaceae) in insect-proof cage experiments in the 1980s, a result that had never been reproduced later. LY has destroyed many coconut plantations as well as other palm species in the Caribbean and Mexico. In order to evaluate if H. crudus is a vector of LY phytoplasmas in Mexico, experiments were carried out in Yucatan (Mexico). Several H. crudus from palms infected by LY in the field were introduced into cages containing young P. pacifica palms. These insects were able to transmit 16SrIV group phytoplasmas to P. pacifica palms. According to DNA sequences comparative analysis, virtual restriction frag- ment length polymorphism, and phylogenetic analysis, the phytoplasmas detected in these infected P. pacifica were of subgroups A and D. All of ten P. pacifica palms infected with the subgroup D phytoplasmas developed symptoms of LY and died, whereas only one of two palms infected with subgroup A developed LY symptoms and died. This is the first time, more than 30 years later, that the role of H. crudus as a vector of LY is confirmed. Introduction The disease lethal yellowing (LY) affecting coconut (Cocos nucifera L.) palms was first reported in the Cayman Islands in the Caribbean in the nineteenth century (Martyn 1945). It was reported later in Florida (USA) around the 1950/1960s (Martinez & Robert 1965; McCoy et al 1983). It was detected in the late 1970s/beginning of the 1980s in México, in the Cancun-Cozumel area in the Yucatan Peninsula (McCoy et al 1982). Later it spread to other parts of Mexico and other countries in Central America (Oropeza & Zizumbo 1997). There are diseases with similar syndrome, but different etiological agent, throughout the world affecting coconut (and other palm species). They are now collectively named lethal yellowing diseases or lethal yellowing–type syndromes (LYTS) (Dollet et al 2009; Eden-Green 1997). In the 1970s, LY was associated with phytoplasmas us- ing electron microscopy in Jamaica and Florida (Beakbane et al 1972; Plavsic-Banjac et al 1972) and differential re- sponse to antibiotics (McCoy 1972; Hunt et al 1974). These findings triggered the search of a LY vector in both countries. The planthopper Haplaxius crudus Van Duzee (Hemiptera: Cixiidae) (ex- Myndus crudus), (Emeljanov 1989, Holzinger et al 2002, Ceotto & Bourgoin 2008, Ceotto et al 2008) was an early suspect due to its pres- ence in coconut plantations, particularly in areas affected by LY (McCoy et al 1983) and because it belongs to the group Auchenorrhyncha, family Cixiidae, that includes Neotrop Entomol https://doi.org/10.1007/s13744-020-00799-2