title: Insecticidal efficacy and persistence of a co-occluded binary mixture of Helicoverpa armigera nucleopolyhedrovirus (HearNPV) variants in protected and field-grown tomato crops on the Iberian Peninsula.
abstract: BACKGROUND
  A binary co-occluded mixture (HearSP1B:LB6) of Helicoverpa armigera single nucleopolyhedrovirus (HearNPV) variants was previously found to be highly pathogenic under laboratory conditions. The insecticidal efficacy and persistence of this mixture were determined in greenhouse and field-grown tomato crops in Spain and Portugal.
  
  
  RESULTS
  Concentrations of 10(9) -10(11) occlusion bodies (OBs) L(-1) of HearSP1B:LB6 resulted in 89-100% mortality of larvae on treated tomato plants in growth chambers. In protected tomato crops, application of 10(10) OBs L(-1) of HearSP1B:LB6 was as effective as Bacillus thuringiensis (Bt) and spinosad in reducing the percentage of damaged fruits, and resulted in higher larval mortality than the Bt treatment. In open-field tomato crops, virus treatments were as effective in reducing the percentage of damaged fruit as spinosad, Bt and chlorpyrifos treatments. The persistence of the insecticides on tomato plants was negatively correlated with solar radiation in both field and greenhouse settings. Residual insecticidal activity of OBs on protected tomato crops at 6 days post-application was 55 and 35% higher than that of Bt and spinosad respectively. On field-grown tomato, OB persistence was significantly lower than with spinosad or chlorpyrifos.
  
  
  CONCLUSIONS
  The efficacy and persistence of HearSP1B:LB6 OBs were comparable with those of commercial insecticides in both field and greenhouse tomato crops. Future studies should focus on reducing application rates to determine insecticidal efficacy at lower OB concentrations. © 2015 Society of Chemical Industry.
authors.affiliation: Instituto de Agrobiotecnología, CSIC-UPNA, Gobierno de Navarra, Mutilva Baja, Spain.
authors.forename: Maite
authors.initials: M
authors.lastname: Arrizubieta
authors.affiliation: Instituto de Agrobiotecnología, CSIC-UPNA, Gobierno de Navarra, Mutilva Baja, Spain.
authors.forename: Oihane
authors.initials: O
authors.lastname: Simón
authors.affiliation: Servicio de Sanidad Vegetal, Consejería de Agricultura DRMAyE, Gobierno de Extremadura, Mérida, Spain.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Torres-Vila
authors.affiliation: Centro de Engenharia dos Biossistemas, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Figueiredo
authors.affiliation: Servicio de Sanidad Vegetal, Consejería de Agricultura DRMAyE, Gobierno de Extremadura, Mérida, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Mendiola
authors.affiliation: Centro de Engenharia dos Biossistemas, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Antonio
authors.initials: A
authors.lastname: Mexia
authors.affiliation: Instituto de Agrobiotecnología, CSIC-UPNA, Gobierno de Navarra, Mutilva Baja, Spain.|Departamento de Producción Agraria, Universidad Pública de Navarra, Pamplona, Spain.
authors.forename: Primitivo
authors.initials: P
authors.lastname: Caballero
authors.affiliation: Instituto de Ecología AC, Xalapa, Veracruz, Mexico.
authors.forename: Trevor
authors.initials: T
authors.lastname: Williams
mesh_terms: D000818:Animals; D004780:Environment, Controlled; D005060:Europe; D014644:Genetic Variation; D007753:Laboratories; D007814:Larva / Q000821:virology; D007915:Lepidoptera / Q000821:virology*; D018551:Solanum lycopersicum / Q000254:growth & development*; D017924:Nucleopolyhedroviruses / Q000235:genetics* / Q000502:physiology*
keywords: Bacillus thuringiensis; alphabaculovirus; crop protection; residual activity; spinosad