Evaluation of the morphological diversity of different populations of Brevipalpus species (Acari: Tenuipalpidae) that are virus vectors

Author(s)

Aline Daniele Tassi

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2014-01-23

Examining board members

Elliot Watanabe Kitajima; Gilberto José de Moraes; Valdenice Moreira Novelli

• Advisor: Elliot Watanabe Kitajima

Abstract

Brevipalpus is a genus of mites belonging to the family Tenuipalpidae (Acari: Prostigmata), which are commonly found in tropical and subtropical regions. The genus includes more than 280 species, and is of economic importance because they cause damage in various crops as pests and also as vector for some plant viruses. B. californicus Banks, B. obovatus Donnadieu and B.phoenicis (Geijskes) are the species known as vector. Brevipalpus species are morphologically very similar, frequently resulting misidentification. Among the virus diseases transmitted by these mites is citrus leprosis which is considered one of the most destructive diseases of citrus industry. Leprosis is one of the most important problem for citrus in the state of São Paulo, Brazil, the world largest producer of orange juice, where about $ 80 million/year are spent with acaricides for control the mite vector B. phoenicis. The present work aimed to give support for the a rapid and accurate identification of species of Brevipalpus, to contribute for the systematic of the group, and relate it to the transmission of viruses, especially of citrus leprosis cytoplasmic type (CiLV-C). The expectation is to contribute for a better understanding of the epidemiology of the CiLV-C and its management. The specific objectives were: 1) To study and describe the phenotypic variation among different species and morphological groups of Brevipalpus mites evaluated by light and scanning electron microscopy. Internal and external morphology of different populations were observed, trying to find characteristics new details, beyond dorsal lateral setae, solenidion on the tarsus of leg II presently used, that could help in the discrimination of species; 2) To contribute to update the list of Brevipalpus mites hosts in Brazil and the world; 3) To assess the hability of distict Brevipalpus populations to transmit plant viruses, especially CiLV-C. In the surveys made, resulting in the analysis of more than 8,000 specimens, collected from 111 plant species in Brazil and several other countries, six different species of Brevipalpus were identified: B. phoenicis, divided into seven morphological groups; B. californicus divided into two morphological groups; B. obovatus; B. chilensis; B. araucanus; B. longisetosus; and Brevipalpus sp. This latter was found in Delonix regia and not identified to species level yet. In Brazil mites were found in 111 species belonging to 45 botanical families. Four species have been identified: B. californicus, B. obovatus and B. phoenicis and Brevipalpus sp. Mite transmission tests, involving CiLV-C, Passion fruit green spot virus (PFGSV) and Solanum violaefolium ringspot virus (SvRSV), only mites species collected in host plants for these viruses were able to transmit these viruses under experimental conditions. (AU)

• FAPESP's process: 11/14496-2 - Evaluation of the morphological and genomic diversity of different populations of Brevipalpus (Acari: Tenuipalpidae) species transmitting plant viruses and their ability as vector
• Grantee: Aline Daniele Tassi
• Support Opportunities: Scholarships in Brazil - Master