The Chrysodeixis chalcites moth is regarded as one of the most serious pests in horticultural, ornamental and fruit crops. On the Canary Islands they can be responsible for losses of up to 30 percent in the total weight of banana plantations. Public University of Navarre researcher Alexandra Bernal has tackled the biotechnological developments needed to obtain a new insecticide to control this pest.
Certain micro-organisms can constitute the active matter to develop bioinsecticides used for pest control. In this case, the researcher used a virus of the baculovirus family, which specifically infect invertebrates and naturally regulate the population of insects of this type on the ground. "We selected a virus that displayed the best insecticidal characteristics," she explained. "Using this virus we developed a large-scale production system by means of which we could treat a surface area equivalent to that of a football pitch using just two larvae."
When a larva infected by the virus dies, it constitutes a fresh source of infection because it contaminates the area where the crops are growing. So other larvae that feed in this area may be infected and die in the same way. To verify the effectiveness of the bioinsecticide, the results were compared with those of the chemical and biological insecticides routinely used on banana plantations on the Canary Islands. "We saw that our product is between 3 and 4 times more effective. We applied for a patent and established the bases to develop a new bioinsecticide, which is also a very useful tool for sustainable agriculture."
In this respect, controlling the pest using the usual treatments, like chemical insecticides, can lead to environmental hazards and leave residues on the surface of the crops, which hampers the marketing of them. "Baculoviruses have generated an interest in the control of insect pests, because of their insecticidal capacity and because of their specificity and safety of use," pointed out Alexandra Bernal, "so some have already been registered as insecticides in several parts of the world."
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Bernal A, Simón O, Williams T, Muñoz D, Caballero P. "A Chrysodeixis chalcites single-nucleocapsid nucleopolyhedrovirus population from the Canary Islands is genotypically structured to maximize survival". 2013.Appl Environ Microbiol. 79(24):7709-18. DOI: 10.1128/AEM.02409-13