Link discovered between guava smell and weevil pest
Researchers from the Universidad Nacional de Colombia (UNC) have discovered a link between the pheromones of the guava weevil and the smell of the fruit, paving the way for a new alternative method of pest control.
The insect, also know as Conotrachelus psidii Marshall, was shown to be influenced by the aroma given off from guava fruit at certain stages of ripening, according the to UNC news website.
As soon as the male insects' pheromones are activated, they send signals to other guava weevils of both sexes letting them know the fruit is ready to be colonized.
"The chemicals responsible for these interactions are known as semiochemicals; the majority are volitile organic compounds - substances which readily diffuse into the environment - which are detected by the insect," UNC researcher Alicia Romero Frias said.
The research marks the first time in Colombia the components of the insect's pheromones have been detected, isolated, identified, characterized and synthesized.
"This is the aggregation pheromone, made up of two volitile organic components that have the same cyclic structure, which seem to be produced by the insect after it consumes any of the components from the host," Romero said.
The study involved three stages: identification of the volatile organic compounds emitted by the insect and from the guava at different stages of development; evaluation of the interactions between the compounds and the guava weevil; and finally a field test of an alternative method for catching the insect, based on the attraction of the semiochemicals.
Romero said the reserach would help to establish "an indicator to establish at what point to apply insecticides, so that it is not done indiscriminately, which can harm the environment."
Photo: Universidad Nacional de Colombia