Helicoverpa armigera has recently been discovered in South America. It has since been tracked spreading into the Caribbean. Pest risk modelling has revealed that most of the US crop production may be at some degree of risk from this pest, which has developed resistance to most pesticides. The rapid northward spread in the Americas suggests that it is now a matter of when, rather than if it will invade the USA. The pest risk research has been published in PLOS One.
H. armigera has been on USDA’s radar for many years, with it being intercepted quite frequently in fresh plant imports arriving by air and sea, and in some cases associated with passengers. The establishment of populations of H. armigera in South America, which have in turn started to spread northwards is changing the nature of the invasion threat to the USA fundamentally from a human-mediated threat to one of natural dispersal.