Is a “super-resistant” insect threatening global agriculture?

Spread the knowledge
Two insects whose larvae are among the worst pests of agriculture have hybridized. Result: voracious parasites and, especially, multi-resistant to pesticides. What cause considerable agricultural losses.

This is a very frightening discovery made by two researchers from the Commonwealth Scientific and Industrial Research Organization (CSIRO), an Australian research organization. Two of the most devastating insects for crops have crossed to give birth to multiple hybrids, discovered in Brazil.

On the one hand,  Helicoverpa armigera (tomato moth): this butterfly, whose larvae attack more than 100 plants including corn, tomato, soya or cotton, causes nearly three billion euros of losses per year globally. The larvae are introduced into the fruit to devour it from the inside and go unnoticed until harvest. This formidable caterpillar has also developed a worrying resistance to pesticides. On the other hand,  Helicoverpa zea (“corn caterpillar”), a species very close, is less dangerous but affects other types of crops (such as pepperscucumbers or salads) and spreads very quickly. In other words, the combination of the two species forms an explosive cocktail.

Appeared in Brazil, these hybrids could migrate

In Brazil, the researchers found no fewer than nine different hybrids, most of them  Helicoverpa zeahaving integrated genes of  Helicoverpa armigera . Their study, published in the  Pnas, is particularly alarmist. “This hybridization represents a new threat that is likely to spread around the world,” said Tom Walsh, one of the co-authors, interviewed by  ABC NewsThese caterpillars attack a very wide variety of crops and seem able to withstand all attempts at control. “

According to Craig Anderson, the other coauthor, no less than 65% of US agriculture is potentially concerned. France is not immune either: with the human displacements and the commercial exchanges, the hybrid tracks could quickly land at home. Several invasive butterflies have already been accidentally introduced into the territory, such as the Anatrachyntis rileyi that attacks maize and lemon trees.

Cultivated plants suffer between 20 and 30% of  losses before harvest. Every year, the insects would cause 69 billion euros of  loss to the world economy, according to a study of 2016. A figure that would be largely underestimated by the admission of its authors.

  • Two caterpillar species, among the most dangerous for the crops, hybridized, making fear an invasion difficult to control.

  • The damage could be very high as these hybrids are resistant to pesticides and attack many plants.

  • Trade could promote their rapid spread to the world.

Dr. Jake Paul

Ph.D Plant Pathology, University of Georgia

Leave a Reply

Your email address will not be published. Required fields are marked *