title: Can a chitin-synthesis-inhibiting turfgrass fungicide enhance black cutworm susceptibility to a baculovirus?
abstract: BACKGROUND
  Developmental resistance, i.e. reduced virulence and speed of kill of late instars, is a limiting factor in the use of baculoviruses for caterpillar control. Agrotis ipsilon multicapsid nucleopolyhedrovirus (AgipMNPV) is highly infective to young black cutworms, Agrotis ipsilon, but too slow-acting against late instars for effective curative control on golf courses or sports fields. Chitin-synthesis-inhibiting fungicides containing the active ingredient polyoxin-d are used to control fungal diseases in turfgrass, and similar compounds have been shown in the laboratory to synergize baculoviruses by disrupting peritrophic membrane function. This study tested whether applying the virus together with such a fungicide can synergize AgipMNPV activity against A. ipsilon in turfgrass.
  
  
  RESULTS
  The addition of a chitin synthesis inhibitor failed to increase AgipMNPV infectivity to A. ipsilon in the field. Rather, delayed and slightly reduced mortality from viral infection was seen when larvae fed on fungicide/virus-treated grasses as opposed to virus-only treatments. Choice tests revealed the fungicide residues to be a mild feeding deterrent.
  
  
  CONCLUSIONS
  Because polyoxin-d does not deactivate AgipMNPV, the two substances are compatible. However, combination applications of polyoxin-d and Agip MNPV on turfgrass might interfere with larval ingestion of a lethal virus dose, resulting in prolonged larval feeding in the field.
authors.affiliation: Department of Entomology, University of Kentucky, Lexington, KY 40546-0091, USA.
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Bixby-Brosi
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Potter
mesh_terms: D000818:Animals; D002686:Chitin / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D005659:Fungicides, Industrial / Q000494:pharmacology*; D007300:Insect Control / Q000379:methods; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000502:physiology / Q000821:virology; D009036:Moths / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000821:virology*; D017924:Nucleopolyhedroviruses / Q000502:physiology*; D010572:Pest Control, Biological / Q000379:methods*; D010935:Plant Diseases / Q000469:parasitology*; D006109:Poaceae / Q000382:microbiology / Q000469:parasitology*; D011741:Pyrimidine Nucleosides / Q000494:pharmacology
chemical_list: D005659:Fungicides, Industrial; D011741:Pyrimidine Nucleosides; D002686:Chitin; C002458:polyoxorim