title: High-resolution melt and morphological analyses of mealybugs (Hemiptera: Pseudococcidae) from cacao: tools for the control of Cacao swollen shoot virus spread.
abstract: BACKGROUND
  Mealybugs (Hemiptera: Coccoidea: Pseudococcidae) are key vectors of badnaviruses, including Cacao swollen shoot virus (CSSV), the most damaging virus affecting cacao (Theobroma cacao L.). The effectiveness of mealybugs as virus vectors is species dependent, and it is therefore vital that CSSV resistance breeding programmes in cacao incorporate accurate mealybug identification. In this work, the efficacy of a CO1-based DNA barcoding approach to species identification was evaluated by screening a range of mealybugs collected from cacao in seven countries.
  
  
  RESULTS
  Morphologically similar adult females were characterised by scanning electron microscopy, and then, following DNA extraction, were screened with CO1 barcoding markers. A high degree of CO1 sequence homology was observed for all 11 individual haplotypes, including those accessions from distinct geographical regions. This has allowed the design of a high-resolution melt (HRM) assay capable of rapid identification of the commonly encountered mealybug pests of cacao.
  
  
  CONCLUSIONS
  HRM analysis readily differentiated between mealybug pests of cacao that cannot necessarily be identified by conventional morphological analysis. This new approach, therefore, has potential to facilitate breeding for resistance to CSSV and other mealybug-transmitted diseases.
authors.affiliation: School of Agriculture, Policy and Development, University of Reading, Reading, UK.
authors.forename: Andy
authors.initials: A
authors.lastname: Wetten
authors.affiliation: 480 London Road, Ditton, Aylesford, Kent, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Campbell
authors.affiliation: Department of Biological, Biomedical and Applied Sciences, University of the West of England, Bristol, UK.
authors.forename: Joël
authors.initials: J
authors.lastname: Allainguillaume
mesh_terms: D000818:Animals; D019195:Badnavirus / Q000502:physiology; D002099:Cacao / Q000502:physiology* / Q000821:virology; D058893:DNA Barcoding, Taxonomic; D003576:Electron Transport Complex IV / Q000235:genetics; D004772:Entomology / Q000379:methods*; D005260:Female; D020387:Food Chain; D006430:Hemiptera / Q000145:classification / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000517:prevention & control; D017422:Sequence Analysis, DNA
chemical_list: D019476:Insect Proteins; D003576:Electron Transport Complex IV
keywords: Cacao swollen shoot virus; DNA barcoding; Pseudococcidae; Theobroma cacao; high-resolution melt; mealybugs