Researcher Alexandra Bernal Rodriguez

The Chrysodeixis chalcites moth is regarded as one of the most serious pests in horticultural, ornamental and fruit crops. Its caterpillars feed on many plant species, including banana plants, and on the Canary Islands they can be responsible for losses of up to 30% in the total weight of the yield. In her PhD thesis read at the NUP/UPNA-Public University of Navarre, Alexandra Bernal-Rodríguez has tackled the biotechnological developments needed to obtain a new insecticide to control this pest, and has already applied for a patent.

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.”

Video. Alexandra Bernal explains her research in the Three Minute Thesis competition

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."

The PhD thesis, “Development of a new bioinsecticide based on a Chrysodeixis chalcites nucleopolyhedrovirus from the Canary Islands”, was supervised by Primitivo Caballero, Professor of the Department of Agricultural Production, and Oihane Simón, researcher at the Institute of Agrobiotechnology. Alexandra Bernal-Rodríguez is an agricultural engineer (specialising in farming) and holds a PhD in Agrobiotechnology from the NUP/UPNA, where she has been a member of the Crop Protection research group.

* Elhuyar translation, published in www.basqueresearch.com