Nematodes treated with particular pheromones more effective against larvae of harmful insects

In agriculture, nematodes are increasingly used to combat pest populations. Some species of these microscopic worms parasitize insect larvae and limit their spread. However, nematodes are not always very efficient with all types of insects and sometimes they may not be resistant to other contrasting methods such as chemical pesticides.

In a new study it is shown that it is possible to treat the nematodes used to kill insects, also called entomopathogenic nematodes, with particular pheromones so that they are more efficient in their parasitic actions in particular against Curculio caryae and Hermetia illucens, two larvae of insect pests for important cultivated plants. The first in particular is a pest of pecan nuts and, if left unchecked, can reduce production by up to 70%.

David Shapiro-Ilan, an entomologist author of the study, found that there are some pheromones in these beneficial nematodes that underlie their behavior. The researcher therefore asked himself if it was possible to use these pheromones in an “artificial” way to convey the behavior of the nematodes in order to kill more parasites.

Together with his colleagues he then exposed the nematodes to a particular pheromone and noticed that they were 28% up to 78% more effective, compared to nematodes not treated with pheromone, in killing the two parasites above.

It is the first time that the pheromone of a nematode has been used to improve its parasitic performance.