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.

Soybean Stem Fly, Melanagromyza sojae (Diptera: Agromyzidae), in the New World: detection of high genetic diversity from soybean fields in Brazil

“…Nevertheless, the fact that M. sojae has been detected across diverse eco-climatic zones at a global scale (Dempewolf, 2004) suggests that it has the potential to establish across the North and South America continents. To assist with biosecurity preparedness, its potential distribution range may benefit from preemptive population modeling, as has been carried out for H. armigera (Kriticos et al, 2015).…”

Mitochondrial DNA COI characterization of Helicoverpa armigera (Lepidoptera: Noctuidae) from Paraguay and Uruguay

“…Since then, H. armigera has been reported from countries neighbouring Uruguay; including Paraguay (Senave, 2013), Argentina (Murúa et al, 2014;Arneodo et al, 2015), and Bolivia (Kriticos et al, 2015). Kriticos et al (2015) modeled the anticipated spread of H. armigera across the southern and northern American continents. The pest has since been detected in Puerto Rico and Florida in the United States of America (Animal and Plant Health Inspection Service, 2015).…”

Pearl Millet: A Green Bridge for Lepidopteran Pests

“…9, No. 6;2017 In recent years, H. armigera has been reported in different crops and Americas regions, and this new record in millet should reinforce attention with this pest in off-season crops (Czepak, Albernaz, Vivan, Guimarães, & Carvalhais, 2013;Specht, Sosa-Gómez, Paula-Moraes, & Yano, 2013;Murúa et al, 2014;Pratissoli, Lima, Pirovani, & Lima, 2015;Kriticos et al, 2015;Krinski & Godoy, 2015).…”