title: Economic injury levels and sequential sampling plans for Frankliniella schultzei in watermelon crops.
abstract: BACKGROUND
  The thrips Frankliniella schultzei is an important watermelon pest. Nevertheless, economic injury levels and sampling plans for this pest have not yet been determined for this crop. Thus, the objective of the present study was to determine the economic injury levels and develop sequential sampling plans for F. schultzei in conditions of low, medium and high fruit prices.
  
  
  RESULTS
  The attack of F. schultzei on watermelon plants at the vegetative stage reduced the crop's productivity, which did not happen at the flowering and fruiting stage. The economic injury levels were 0.09, 0.04 and 0.02 thrips leaf-1when the watermelon price was low ($US 62.5 t-1), medium ($US 140.63 t-1) and high ($US 218.75 t-1) respectively. The three sequential sampling plans for F. schultzei generated for the economic injury levels resulted in similar and more rapid decisions compared with the conventional plan, especially when the pest density was high.
  
  
  CONCLUSIONS
  The three economic injury levels and the sequential sampling plans generated in the present study can be incorporated into integrated pest management programmes for watermelon crops because these plans provide a rapid and adequate control decision for F. schultzei. © 2016 Society of Chemical Industry.
authors.affiliation: Federal University of Tocantins (UFT), Gurupi, Tocantins, Brazil.
authors.forename: Poliana S
authors.initials: PS
authors.lastname: Pereira
authors.affiliation: Federal University of Tocantins (UFT), Gurupi, Tocantins, Brazil.
authors.forename: Renato A
authors.initials: RA
authors.lastname: Sarmento
authors.affiliation: Department of Entomology, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Tarcísio Vs
authors.initials: TV
authors.lastname: Galdino
authors.affiliation: Federal University of Tocantins (UFT), Gurupi, Tocantins, Brazil.
authors.forename: Carlos Ho
authors.initials: CH
authors.lastname: Lima
authors.affiliation: Federal University of Tocantins (UFT), Gurupi, Tocantins, Brazil.
authors.forename: Fábio A
authors.initials: FA
authors.lastname: Dos Santos
authors.affiliation: Federal University of Tocantins (UFT), Gurupi, Tocantins, Brazil.
authors.forename: Joedna
authors.initials: J
authors.lastname: Silva
authors.affiliation: Federal University of Tocantins (UFT), Gurupi, Tocantins, Brazil.
authors.forename: Gil R
authors.initials: GR
authors.lastname: Dos Santos
authors.affiliation: Department of Entomology, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Marcelo C
authors.initials: MC
authors.lastname: Picanço
mesh_terms: D000818:Animals; D029773:Citrullus; D018556:Crops, Agricultural; D005638:Fruit / Q000191:economics*; D007300:Insect Control / Q000191:economics* / Q000379:methods; D018515:Plant Leaves; D061149:Thysanoptera
keywords: Citrullus lanatus; decision-making; sampling plan validation; thrips