title: The potential distribution of invading Helicoverpa armigera in North America: is it just a matter of time?
abstract: Helicoverpa armigera has recently invaded South and Central America, and appears to be spreading rapidly. We update a previously developed potential distribution model to highlight the global invasion threat, with emphasis on the risks to the United States. The continued range expansion of H. armigera in Central America is likely to change the invasion threat it poses to North America qualitatively, making natural dispersal from either the Caribbean islands or Mexico feasible. To characterise the threat posed by H. armigera, we collated the value of the major host crops in the United States growing within its modelled potential range, including that area where it could expand its range during favourable seasons. We found that the annual value of crops that would be exposed to H. armigera totalled approximately US$78 billion p.a., with US$843 million p.a. worth growing in climates that are optimal for the pest. Elsewhere, H. armigera has developed broad-spectrum pesticide resistance; meaning that if it invades the United States, protecting these crops from significant production impacts could be challenging. It may be cost-effective to undertake pre-emptive biosecurity activities such as slowing the spread of H. armigera throughout the Americas, improving the system for detecting H. armigera, and methods for rapid identification, especially distinguishing between H. armigera, H. zea and potential H. armigera x H. zea hybrids. Developing biological control programs, especially using inundative techniques with entomopathogens and parasitoids could slow the spread of H. armigera, and reduce selective pressure for pesticide resistance. The rapid spread of H. armigera through South America into Central America suggests that its spread into North America is a matter of time. The likely natural dispersal routes preclude aggressive incursion responses, emphasizing the value of preparatory communication with agricultural producers in areas suitable for invasion by H. armigera.
authors.affiliation: CSIRO, GPO Box 1700, Canberra, ACT, Australia; School of Biological Sciences, Faculty of Science, The University of Queensland, Queensland, 4072 Australia.
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Kriticos
authors.affiliation: CSIRO, Private Bag 5, Wembley WA, Australia.
authors.forename: Noboru
authors.initials: N
authors.lastname: Ota
authors.affiliation: Department of Entomology, University of Minnesota, St. Paul, Minnesota, United States of America.
authors.forename: William D
authors.initials: WD
authors.lastname: Hutchison
authors.affiliation: Department of Applied Economics, University of Minnesota, St. Paul, Minnesota, United States of America.
authors.forename: Jason
authors.initials: J
authors.lastname: Beddow
authors.affiliation: CSIRO, GPO Box 1700, Canberra, ACT, Australia.
authors.forename: Tom
authors.initials: T
authors.lastname: Walsh
authors.affiliation: CSIRO, GPO Box 1700, Canberra, ACT, Australia.
authors.forename: Wee Tek
authors.initials: WT
authors.lastname: Tay
authors.affiliation: Animal and Plant Health Inspection Service-Plant Protection and Quarantine-Center for Plant Health Science and Technology, Plant Epidemiology and Risk Analysis Laboratory, Raleigh, North Carolina, United States of America.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Borchert
authors.forename: Silvana V
authors.initials: SV
authors.lastname: Paula-Moraes
authors.affiliation: Embrapa Cerrados, BR 040 km 18, Planaltina-DF, Brasil.
authors.forename: Silvana V
authors.initials: SV
authors.lastname: Paula-Moreas
authors.affiliation: Escola de Agronomia e Engenharia de Alimentos, Universidade Federal de Goiás. Campus II, Caixa Postal 131, CEP, Goiânia, Brasil.
authors.forename: Cecília
authors.initials: C
authors.lastname: Czepak
authors.affiliation: School of Biological Sciences, Faculty of Science, The University of Queensland, Queensland, 4072 Australia.
authors.forename: Myron P
authors.initials: MP
authors.lastname: Zalucki
mesh_terms: D000383:Agriculture / Q000379:methods; D063147:Animal Distribution / Q000502:physiology*; D000818:Animals; D007300:Insect Control / Q000379:methods*; D058865:Introduced Species / Q000191:economics / Q000706:statistics & numerical data* / Q000639:trends; D009036:Moths / Q000502:physiology*; D009656:North America