First record of a new microsporidium pathogenic to Gonipterus platensis in Brazil

Made available in DSpace on 2021-06-25T11:01:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Microsporidia are naturally occurring fungal-related parasites that can infect nearly all animal hosts, but their biocontrol potential of insect pests is routinely overlooked in agriculture and forestry. This research brings the first report describing the natural occurrence of a microsporidium causing disease in field-collected populations of the invasive eucalyptus snout beetle, Gonipterus platensis (Coleoptera: Curculionidae), a major destructive pest of eucalyptus plantations in Brazil. Adult beetles were collected during field surveys in commercial eucalyptus plantations in southern Brazil to be examined and dissected with typical symptoms to verify presence of microsporidian spores in haemolymph. From 14 plantations in different sites, the natural infection occurrence in these populations ranged from 0 to 65%, while a lab colony exhibited an infection incidence of 70%. Spore density in haemolymph of symptomatic insects averaged 2.1 (± 0.4) × 107 spores/beetle. Symptoms in infected adults were identified by an abnormal abdomen with malformation of the second pair of wings, impairing their flight activity. Electron transmission microscopy of the pathogen showed morphological features similar to species belonging to the genus Nosema or Vairimorpha. Phylogenetic analysis of the full-length small subunit ribosomal RNA gene suggests this pathogen’s placement in the genus Vairimorpha, but with a sequence identity of ~ 94% with the nearest neighbours. The low level of sequence identity suggests this pathogen may represent a novel taxon in the genus and further requires whole genome sequencing for definitive taxonomic resolution. These findings provide insights on the natural occurrence of this novel pathogen of this invasive pest in Eucalyptus plantations in Brazil. Further studies are needed to determine potential of this microsporidium in the design of conservative or augmentative biological control programs for this invasive pest. School of Agricultural Sciences São Paulo State University (UNESP), Campus of Botucatu, Av. Universitária, 3780, Altos do Paraíso, Fazenda Experimental Lageado Laboratory of Environmental Microbiology Brazilian Agricultural Research Corporation Embrapa Environment, Rodovia SP-340, km 127.5 Botucatu Medical School Dept. Internal Medicine Sao Paulo State University (UNESP), Campus of Botucatu, Av. Prof. Mário Rubens Guimarães Montenegro, s/n USDA Agricultural Research Service National Center for Agricultural Utilization Research Crop Bioprotection Research Unit, 1815, N. University St School of Agricultural Sciences São Paulo State University (UNESP), Campus of Botucatu, Av. Universitária, 3780, Altos do Paraíso, Fazenda Experimental Lageado Botucatu Medical School Dept. Internal Medicine Sao Paulo State University (UNESP), Campus of Botucatu, Av. Prof. Mário Rubens Guimarães Montenegro, s/n