“Be afraid, be very afraid!” Kate Jones warned me over coffee in London. She is an expert on global emergent diseases. Her work showed that new diseases are on the increase and that they usually originate from contact with wild animals as our species occupies and further exploits natural areas on the planet (1). I remembered her warning a few years later in 2014–2015 when an unprecedented Ebola epidemic broke out in West Africa and threatened the rest of the planet. This lethal epidemic likely started because someone, somewhere, cooked and ate a virus-laden bat. In PNAS, Anderson et al. (2) provide another reason to be very afraid: a “mega-pest” of food and fiber has recently invaded the New World from the Old and has begun to mix its genome with a native mega-pest.

The genus Helicoverpa belongs to a group of heliothine moths in the family Noctuidae that are considered mega-pests because of the immense crop damage they cause (3). The Helicoverpa corn earworm and cotton bollworm complex of moth pests (Lepidoptera) are among the world’s most devastating pests of food and fiber crops. Helicoverpa zea is the New World representative, mainly known for its depredations on cotton and corn, and also found on over 100 other plant species belonging to 29 plant families (4). It causes hundreds of millions of dollars of annual damage. Its close relative, the Old World Helicoverpa armigera, is even more devastating, particularly in tropical Africa and Asia. This second pest feeds on over 300 species belonging to 68 plant families and is estimated to inflict over $5 billion of damage annually to crops worldwide (4). Helicoverpa caterpillars are particularly challenging because they prefer to bore into plant reproductive parts, the fruits and/or flowers of crops, the very same parts that are valuable …

↵¹Email: jmallet{at}oeb.harvard.edu.